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[74] viXra:1905.0406 [pdf] replaced on 2020-12-31 01:24:22
Authors: Yongnan Kim, Myongchol Ryu
Comments: 9 Pages.
We studied on the methods involving the recovery of chromate salt from COPR, the sequential detoxification of COPR and the reclamation of the detoxified COPR. The results of leaching experiments showed that it is possible to recover Cr (VI) existed in COPR using an inexpensive method, in which ca. 84% of Cr (VI) extraction rate could be under the following condition; seawater as leaching solution, 25% of solid content, leaching period of 30min, intermittent agitation, gravitational sedimentation as solid/liquid separating mode, repetition number of up 5. Cr (VI) contained in leaching liquor was recovered as chrome yellow, followed by recirculating the Cr (VI)-depleted supernatant to the leaching process. For the detoxification of post-leach COPR (plCOPR), plCOPR was mixed with sodium sulfide as a single reductant in a mixer and was discharged from the mixer without retention time for reduction. Cr (VI) content in the mixture became lower than cleanup criteria by US EPA with the Na2S/Cr (VI) mass ratio of 6 at the reaction time of 36h. Also, the results of the experiment with the detoxified plCOPR as a substitution for sand in fabricating clay brick shows that acceptable compression strength (52N/mm2) is obtained when the detoxified COPR accounts for '30% in raw material mixture, with the Cr (VI) content of 0.5mglkg-bricks below cleanup criteria by US EPA.
Category: Chemistry
[73] viXra:1905.0388 [pdf] submitted on 2019-05-19 05:51:53
Authors: Venkata Narayana A, Vamsi Priya A, Venkata Nadh R, Swami AVN, Sumalatha B, Vijaya Leela M
Comments: Pages.
Production of L-methionine by Cornybacterium glutamicum MTCC 2745 was assessed in batch fermentation by varying parameters viz., initial glucose concentration, initial nitrogen concentration, fermentation time, temperature, pH, initial shaking rate. Nynhydrin test and paper chromatography were used to identify methionine. Methionine estimated by using nitroprusside method. Effect of nitrogen sources on methionine production was examined. The parameters such as concentrations of glucose, ammonium sulphate, K2HPO4, MgSO47H2O, 3,4-dihydroxy benzoic acid and Yeast extract are optimized and maximum yield was 5.6 g of methionine/L.
Category: Chemistry
[72] viXra:1905.0387 [pdf] submitted on 2019-05-19 05:53:58
Authors: Muvvala Subrahmanya Sudhir1, Pavuluri Madan Mohan, Ratnakaram Venkata Nadh
Comments: 6 Pages. OK
For estimation of the Febuxostat in bulk and pharmaceutical dosage forms, an ultra violet
– spectrophotometric method has been developed and validated. The method employed 0.1 N
NaOH as solvent. At 275 nm, the linear regression analysis data for the calibration plot showed
good linear relationship with correlation coefficient value of 0.998 in the concentration range of 10
– 70 μg/ml. The limit of detection and limit of quantitation were found to be 0.239 μg/ ml and 0.725
μg/ml respectively. The results demonstrated that the pro-cedure is accurate, precise and
reproducible (R.S.D. < 2 %).
Category: Chemistry
[71] viXra:1905.0386 [pdf] submitted on 2019-05-19 05:55:52
Authors: K. Kiran Kumar1, R. Venkata Nadh, K.e.v. Nagoji3
Comments: 7 Pages. OK
Two simple, sensitive, selective, accurate and economical spectrophotometric methods
(A and B) have been described in the present work for the determination of Nicergoline in bulk drug
and pharmaceutical formulations (tablets). Methods – A/B are based on the formation of orange
red / yellow colored ion-association complexes between Nicergoline and Tropaeolin ooo (TPooo)
/ Alizarine Red S (ARS) in acid medium followed by their extraction with chloroform, exhibiting
absorption maxima at 490nm / 430nm, and obeying Beer’s law in the concentration range of 2.5–
12.5μg/ml. Statistical analysis of the results of the proposed methods reveals high accuracy and
good precision. The proposed methods could be
Category: Chemistry
[70] viXra:1905.0385 [pdf] submitted on 2019-05-19 05:57:26
Authors: K. K. Kumar, K. E. V. Nagoji, R. V. Nadh
Comments: 5 Pages. OK
A simple, selective, rapid, precise and economical reverse‑phase high‑performance liquid chromatography method
has been developed for the determination of lapatinib in tablet using gemcitabine hydrochloride as an internal
standard. Chromatography was carried out on an ODS C‑18 RP column (4.6 mm i.d. ×250 mm) using a mixture
of acetonitrile and water (50:50 v/v) as the mobile phase at a flow rate of 1.0 ml/min. The drug was monitored
at 232 nm. The retention times for lapatinib and gemcitabine hydrochloride were found to be 4.25±0.05 and
6.10±0.05 min, respectively. The method produced linear responses in the concentration range of 2‑60 μg/ml of
lapatinib. The limit of detection and limit of quantitation were 0.265 and 0.884 μg/ml, respectively.
Category: Chemistry
[69] viXra:1905.0384 [pdf] submitted on 2019-05-19 05:59:03
Authors: Y. Lakshman Kumar 2, R. Venkata Nadh, P.s. Radhakrishnamurti 2
Comments: 4 Pages. OK
Kinetics of oxidation of myo-inositol by potassium periodate both in alkaline and acid media were studied. The reactions were found to
be first order in case of periodate in both media. In the case of base catalyzed reactions, a decrease in the rate of the reaction was observed
with an increase in the concentration of substrate. An inverse fractional order with respect to substrate in alkaline shows the substrate
inhibition. A positive fractional order was observed for substrate in acid catalyzed reactions. The dependence on hydrogen ions and
hydroxide ions was found to be inverse fractional order. Arrhenius parameters were calculated for both the reactions conducted in acid and
alkali media. Plausible mechanism is postulated based on experimental results.
Category: Chemistry
[68] viXra:1905.0383 [pdf] submitted on 2019-05-19 06:00:10
Authors: Sudhir S Muvvala1, Venkata Nadh Ratnakaram, Rama RaoNadendla3
Comments: 9 Pages. OK
An accurate, sensitive, precise and robust reverse phase high performance liquid
chromatographic (RP-HPLC) method for the estimation of Febuxostat in bulk forms has been developed and
validated. Chromatographic separation is conducted on Nucleosil C18 (250 x 4.6mm, 5μm) column at
ambient temperature using mixture of 10 mM ammonium acetate buffer (buffer of pH 4.0 adjusted with 0.2%
triethyl amine) and acetonitrile in the ratio (15: 85, v/v) as a mobile phase and at a flow rate of 1.2 ml / min,
while UV detection is performed at 275nm. The retention time for Febuxostat is found to be 3.45 ± 0.05
min. The method is found to be linear in the range of 50.0 – 400.0 μg/mL. The limit of detection and
quantization for Febuxostat are found to be 9.98 and 30.23 μg /mL respectively. Analytical recovery is 99.29
%. The percentage RSD for precision and accuracy of the method is found to be less than 2%. The method is
validated as per the ICH guidelines and applied for the quantitative analysis of Febuxostat in bulk forms.
Category: Chemistry
[67] viXra:1905.0382 [pdf] submitted on 2019-05-19 06:02:31
Authors: K.Kiran Kumar1, R. Venkata Nadh
Comments: 5 Pages. OK
A simple, selective, rapid, precise and economical reverse phase HPLC method has been developed for the
determination of melphalan in tablet. The analyte was resolved by using a mobile phase (Acetonitrile, water and
1% ortho phosphoric acid in the ratio 70:27:3 v/v/v) at a flow rate 1 ml/min on an isocratic HPLC system (PEAK)
consisting UV-Visible detector, ODS C-18, RP column (4.6 mm i.d x250 mm) at a wavelength of 275 nm. The
linear dynamic range for melphalan was 2.0 μg/mL – 14.0μg/mL. The limit of detection [LOD] and Limit of
quantification [LOQ] for melphalan was 0.5μg/mL and 1.5μg/mL respectively.
Category: Chemistry
[66] viXra:1905.0381 [pdf] submitted on 2019-05-19 06:04:47
Authors: K.Kiran Kumar, R. Venkata Nadh
Comments: 5 Pages. OK
A simple, selective, accurate, and economical reverse phase high performance liquid chromatography (RP-HPLC)
was developed for estimation of nicergoline in pharmaceutical formulations. Chromatographic separation achieved
isocratically on a C18column (ODS, C18, 5μ, 250×4.6 mm i.d.) with mobile phase containing methanol, acetonitrile
and 1.0 % ortho phosphoric acid in the ratio 80:18:2 v/v/v. The flow rate was 1.0mL/min and effluent was
monitored at 265nm. The retention time was 3.128min. The method was validated in terms of linearity, accuracy and
precision. The linearity curve was found to be linear over 1.0 - 6.0 μg/mL. The limit of detection and limit of
quantification were found to be 0.3 μg /ml and 0.9 μg /ml respectively. The proposed method was successfully used
to determine the drug content of marketed formulations.
Category: Chemistry
[65] viXra:1905.0380 [pdf] submitted on 2019-05-19 06:08:24
Authors: K. Kiran Kumar1, R. Venkata Nadh
Comments: 5 Pages. OK
A simple, selective, rapid, precise and economical reverse phase HPLC method has been developed for the
determination of satranidazole in pharmaceutical formulations. The method was carried out on a isocratic ODS -
C18 (250 x 4.6mm i.d.,5 μ) column with a mobile phase consisting of Acetonitrile , 0.025M Ammonium phosphate
buffer and 1.0% Ortho phosphoric acid in the ratio 65:35:5 v/v/v) at a flow rate 1.2mL/min. Detection was carried
out at 318nm using UV lamp visible detector. The developed method was validated in terms of accuracy, precision,
linearity, limit of detection, limit of quantitation and solution stability. The proposed method can be used for the
estimation of satranidazole in pharmaceutical formulations.
Category: Chemistry
[64] viXra:1905.0378 [pdf] submitted on 2019-05-19 06:11:11
Authors: R.Venkata Nadh, B.Syama Sundar, P.S. Radhakrishnamurti
Comments: 8 Pages.
Kinetics of Oxidation of Iodide ion by Cerium (IV),
Category: Chemistry
[63] viXra:1905.0377 [pdf] submitted on 2019-05-19 06:13:11
Authors: R.Venkata Nadh, B.Syama Sundar, P.S. Radhakrishnamurti
Comments: 5 Pages. OK
Kinetics of oxidation of iodide ion by Vanadium (V),
Category: Chemistry
[62] viXra:1905.0376 [pdf] submitted on 2019-05-19 06:14:13
Authors: R.Venkata Nadh, B.Syama Sundar, P.S. Radhakrishnamurti
Comments: 6 Pages. OK
Kinetic Studies of thiocyanate and iodide oxidation with 2,6-dichloro-quinone-4-chloro-imide: A novel and a new oxidising agent,
Category: Chemistry
[61] viXra:1905.0375 [pdf] submitted on 2019-05-19 06:15:47
Authors: R.Venkata Nadh, B.Syama Sundar, P.S. Radhakrishnamurti
Comments: 8 Pages. OK
Kinetics of oxidation of ethylamine, monoethanolamine and benzylamine by chloramine-T
Category: Chemistry
[60] viXra:1905.0374 [pdf] submitted on 2019-05-19 06:17:44
Authors: R.Venkata Nadh, B.Syama Sundar, P.S. Radhakrishnamurti
Comments: 6 Pages. OK
Kinetics of oxidation of aniline, p-aminobenzoic acid and p-nitroaniline by 2,6-dichloro quionone-4-chloro-imide
Category: Chemistry
[59] viXra:1905.0373 [pdf] submitted on 2019-05-19 06:20:22
Authors: R.Venkata Nadh, B.Syama Sundar, P.S. Radhakrishnamurti
Comments: 5 Pages. OK
Kinetics of reduction of substituted cobaloximes by iron(II)
Category: Chemistry
[58] viXra:1905.0372 [pdf] submitted on 2019-05-19 06:21:46
Authors: R.Venkata Nadh, B.Syama Sundar, P.S. Radhakrishnamurti
Comments: 5 Pages. OK
Kinetics of oxidation of ethylamine, monethanolamine and benzylamine by N-bromosuccinimide,
Category: Chemistry
[57] viXra:1905.0341 [pdf] submitted on 2019-05-19 01:47:28
Authors: Arunkumar Thiriveedhi, Ratnakaram Venkata Nadh, Navuluri Srinivasu, Yamini Bobde c, Balaram Ghosh c, Kondapalli Venkata Gowri Chandra Sekhar
Comments: 10 Pages. OK
The new pyrimidine-pyrrole scaffolds (7a–7m) with substituted 1,2,3-traizole moiety were synthesized in good
to mild yields and subjected for anti-cancer activity against melanoma and breast cancer cell lines using MTT
assay. The compounds 7f and 7m exhibited highest anti-cancer activity against both the tested cell lines in in
vitro assay. The molecular docking analysis provided the insights of binding orientation of pyrimidine-pyrrole
nucleus of current ligands and their crucial interactions with Cys797 and other residues of the EGFR tyrosine
kinase active site. The interactions of triazole and its various substituted groups with EGFR tyrosine kinase have
been discussed
Category: Chemistry
[56] viXra:1905.0340 [pdf] submitted on 2019-05-19 01:53:49
Authors: Giri Prasad Gorumutchu, Venkata Nadh RATNAkaram, Kishore VNV
Comments: 6 Pages. OK
A visible spectrophotometric method was developed and validated for the determination of gemigliptin present in bulk drug and tablet formulation. It involves an indirect method of charge transfer complex formation in presence of NBS, metol and suphanilic acid. Gemigliptin was subjected to oxidation with excess amount of oxidant (NBS) and the unconsumed NBS oxidizes metol to give p-N-methylbenzoquinone monoamine (PNMM) which in turn forms a charge transfer complex with sulphanilic acid. Then validated the above developed method as per the current ICH guidelines. An excellent correlation coefficient (> 0.999) was found for the obtained regression equation
(y = –0.0302x + 0.928) in the range of 2.0–30.0 μg mL-1. The method was found to be simple and rapid because it does not involve any solvent extraction. The recovery levels of the drug were in the range 99.92 – 100.08.
Category: Chemistry
[55] viXra:1905.0339 [pdf] submitted on 2019-05-19 01:55:32
Authors: M. S. Sudhira, R. Venkata Nadh, H. Manjunatha
Comments: 6 Pages. OK
A simple, sensitive, precise, accurate, highly reproducible and economical, visible spectrophotometric
method for the determination lurasidone in bulk form was developed and validated. The method is
based on the formation of an oxidative coupling product by the reaction of lurasidone with 3-methylbenzothiazolin-
2-one hydrazone as a chromogenic reagent in presence of ferric chloride. The linear regression
analysis data for the calibration plot showed good linear relationship within the concentration range of 0–100
μg/mL with a correlation coefficient (r) value of 0.9997. The limits of detection and quantitation are 0.6 and
1.7 μg/mL, respectively. The method was tested and validated according to ICH guidelines. The results
demonstrated that the procedure is accurate, precise and reproducible (RSD < 2%).
Category: Chemistry
[54] viXra:1905.0338 [pdf] submitted on 2019-05-19 01:58:01
Authors: Arunkumar Thiriveedhi, Ratnakaram Venkata Nadh, Navuluri Srinivasu1, Narayana Murthy Ganta3
Comments: 8 Pages. OK
Abstract: Background: Nowadays, hybrid drugs have gained a significant role in the treatment of different
health problems. Most of the hybrid molecules with different heterocyclic moieties were proved
to be potent anti-tumor agents in cancer chemotherapy. Hence, the present study is aimed at the evaluation
of in vitro anticancer activity of novel hybrid molecules (pyrazolyl benzoxazole conjugates) and to
investigate their anticancer activity by molecular docking studies.
Methods: Designed, synthesized and characterized the novel pyrazolyl benzoxazole conjugates.
Anticancer activity of these compounds was determined by SRB assay. Then molecular docking studies
were carried out against proto-oncogene tyrosine-protein kinase (ATP-Src, PDB: 2BDF), a putative
target for cancer.
Results: All the synthesized compound derivatives were evaluated against MCF-7, KB, Hop62 and
A549 cancer cell lines. Compounds 9b and 9c exhibited excellent anticancer activities with GI50 values
of <0.1 μM against MCF-7 and A549 cell lines. Compound 9e exhibited good antitumor activity on
MCF-7 and A-549 with GI50 values of 0.12 μM and 0.19 μM respectively. Compound 9g showed better
anticancer activity on A-549 cancer cell line with GI50 value of 0.34 μM.
Conclusion: The two-hybrid molecules 9b and 9c are found to be comparably potent with the standard
drug doxorubicin and may act as drug lead compounds in medicinal chemistry aspect. The present
docking investigation proved that having benzoxazole of compound 9c at benzofuran of reference
compound N-acetyl pyrazoline derivative might be valid for contributing to anti-cancer activity.
Category: Chemistry
[53] viXra:1905.0337 [pdf] submitted on 2019-05-19 02:00:27
Authors: Giri Prasad Gorumutchu, Venkata Nadh RATNAkaram, Sireesha Malladi 3
Comments: 6 Pages. OK
A simple spectrophotometric method was developed to determine riociguat in bulk and tablet formulation. The present method lies on the oxidation of MBTH by Fe+3 ions in acidic medium to form active coupling species and followed by its coupling with riociguat to form the chromophore having lmax 660 nm. Validated the proposed method as per the existing guidelines of ICH. Good linearity (r~ 0.999) was observed for calibration curve in the studied concentration range (6.25 – 37.50 μg mL-1). Reproducibility, accuracy and precision of the method were confirmed from low values of % RSD.
Category: Chemistry
[52] viXra:1905.0336 [pdf] submitted on 2019-05-19 02:02:00
Authors: K. Kiran Kumar, R.Venkata Nadh, M. Siva Kishore1, G. Giri Prasad3
Comments: 5 Pages. OK
A simple, selective, accurate and low-cost spectrophotometric method
has been described for determination of satranidazole in bulk and
pharmaceutical formulations. The developed method involves the
formation of chloroform extractable colored ion-association complex
of satranidazole with Tropaeolin OOO (TPooo). The extracted colored
complex showed absorbance maximum at wavelength 484 nm and
obeying Beer′s law in the concentration 4-20 μg mL-1 with the
correlation coeffiecent of 0.9998. The results of statistical analysis of
the proposed method reveals high accuracy and good precession. Thus,
the proposed method can be used commercially for the determination
of satranidazole in bulk and pharmaceutical formulations.
Category: Chemistry
[51] viXra:1905.0335 [pdf] submitted on 2019-05-19 02:03:35
Authors: Giri Prasad Gorumutchu, Ven kata Nadh RATNAkaram, Sireesha Malladi 3
Comments: 7 Pages. OK
A simple method is described to determine the amount of gemigliptin in bulk and tablet formulation by visible spectrophotometry. Basis of the proposed method is the reaction of the primary amine present on gemigliptin with ninhydrin in alkaline pH (alkaline borate buffer) medium to produce a purple color (Ruhemann’s purple) which has maximum absorption at 558 nm. The method was validated as per the current ICH guidelines. The obtained regression equation (y = 0.0148x+0.0011) in the range of 5-30 μg mL-1 has a good correlation coefficient (> 0.999). As the method does not require any separation, it is rapid and simple. The recovery levels of the drug were in the range of 99.73 – 99.96. This method is a green method as it no organic solvents were employed.
Category: Chemistry
[50] viXra:1905.0334 [pdf] submitted on 2019-05-19 02:05:22
Authors: Giri Prasad Gorumutchu, Venkata Nadh Ratnakaram
Comments: 6 Pages. OK
Ulipristal acetate is used to treat uterine fibroids and for emergency birth control. The present study is a first report on development of a visible spectrophotometric method for determination of Ulipristal acetate present in bulk and tablet formulation. The method involves the sequential addition of HCl (0.1 N) and Napthol Blue Black solution to Ulipristal acetate. Cation formed on tertiary amine group of Ulipristal acetate attracts anion of naphthol blue black (an acid dye) to develop a coloured ion-association complex. From the aqueous phase, the chromophore is extractable into chloroform, which exhibits λmax at 640 nm. As per the existing guidelines of ICH, various parameters of the method were tested for validation. Regression analysis (r > 0.999) shows that the plotted calibration curve exhibits good linearity in the studied range of concentration (2.50 – 15.00 μg mL-1). The % recovery values falls in 99.80 – 100.72 range. %RSD results of both precision studies were observed in the range 0.007 – 0.560, indicating the satisfactory precision of the method. Low values of R.S.D. (< 1 %) were observed indicating that the proposed method is reproducible, accurate and precise. The proposed method can be used in quality control laboratories for routine analysis of Ulipristal acetate (bulk drug and pharmaceutical dosage forms) without requirement of expensive instruments.
Category: Chemistry
[49] viXra:1905.0333 [pdf] submitted on 2019-05-19 02:07:35
Authors: Giri Prasad Gorumutchu, Venkata Nadh Ratnakaram, Kiran Kumar Katari3
Comments: 5 Pages. OK
Objective: The objective of the study was to develop a simple, validated, and affordable visible spectrophotometric method for determination of
piperacillin (PIP) present in bulk and powder for injection formulation.
Methods: In the present method, cobalt thiocyanate (CTC) was used as a chromogenic reagent where it forms 2:1 ion pair complex at pH 2 with PIP
which is having secondary and tertiary amine groups.
Results: The formed bluish-green colored ion pair between PIP and CTC is quantitatively extractable into nitrobenzene with an absorption maximum of
665 nm. Regression analysis (r=0.9996) shows that the plotted calibration curve exhibits good linearity in the studied range of concentration (3–18 μg/mL).
Low values of relative standard deviation (<2%) were observed indicating that the proposed method is reproducible, accurate, and precise.
Conclusions: As per the existing guidelines of ICH (international council for harmonization of technical requirements for pharmaceuticals for human
use), various parameters of the proposed method were tested for validation and can be used method of choice for routine analysis in industrial quality
control laboratories, especially in developing countries.
Category: Chemistry
[48] viXra:1905.0332 [pdf] submitted on 2019-05-19 02:11:37
Authors: Giri Prasad G, Venkata Nadh R, Kiran Kumar K
Comments: 8 Pages. OK
Ion associative complex formation for the stimation of piperacillin
Category: Chemistry
[47] viXra:1905.0331 [pdf] submitted on 2019-05-19 02:13:33
Authors: Giri Prasad Gorumutchu, Venkata Nadh Ratnakaram
Comments: 4 Pages. OK
Mianserin is used as an antidepressant medication. A visible spectrophotometric method was developed for
determination of Mianserine present in bulk and tablet formulation. The basis of the proposed method is
formation of a chromophore (of λ max 484 nm) in presence of Fe3+-Phenanthroline. Optimization of reaction
conditions was carried out to get highly sensitive and stable colored complex. The proposed method does not
require a pre-treatment process. The method has the advantage of simple, reproducible, selective and sensitive.
Regression analysis (r > 0.999) shows that the plotted calibration curve exhibits good linearity in the studied
range of concentration (1 – 6 μg mL-1). The % recovery values falls in 98.00 – 99.66 range. As per the existing
guidelines of ICH, various parameters of the method were tested for validation. %RSD results of both precision
studies were observed in the range 0.181 – 0.530 and -0.135 – 0.408 respectively, indicating the satisfactory
precision of the method. Low values of R.S.D. (< 2 %) were observed indicating that the proposed method is
reproducible, accurate and precise. The proposed method can be used in routine analysis of Mianserine (bulk
drug and pharmaceutical dosage forms) in quality control laboratories, as an alternative to the methods which
require expensive instruments.
Category: Chemistry
[46] viXra:1905.0330 [pdf] submitted on 2019-05-19 02:16:43
Authors: Giri Prasad Gorumutchu1, Venkata Nadh Ratnakaram
Comments: 6 Pages. OK
Objective: The present study was aimed at the development of a simple visible spectrophotometric method for the assay of mianserin, a drug used for the treatment of depression.
Methods: The method was developed using tropaeolin-ooo (TPooo) as an ion associative complex forming a chromophore. Developed the chromophore by sequential mixing of aqueous solutions of mianserin, hydrochloric acid, and TPooo. Chromophore was extracted into an organic solvent (chloroform) and absorbance values of organic layers were measured. As per the existing guidelines of an international conference on harmonization (ICH), various parameters of the method were tested for validation.
Results: At the optimized reaction conditions, the formed chromophore (λ max
Conclusion: Due to lack of pre-treatment process for this method, it was simple. All the tested parameters of the method were validated as per ICH guidelines.
Category: Chemistry
[45] viXra:1905.0329 [pdf] submitted on 2019-05-19 02:19:27
Authors: Sireesha Malladi, Venkata Nadh Ratnakaram, K. Suresh Babu, M. Sreenivasulu
Comments: 13 Pages. OK
In history, medicinal plants were proven as a source of active compounds with therapeutic applications, and at present, they are an important collection for the discovery of novel drug leads. Caralluma is a genus used as traditional medicine. The present article thoroughly reviewed about the classification of Caralluma into subgenera, number of its species, its distribution in different parts of the world, and pharmacological activities exhibited by different species of Caralluma.
Category: Chemistry
[44] viXra:1905.0328 [pdf] submitted on 2019-05-19 02:21:12
Authors: Giri Prasad Gorumutchu, Venkata Nadh Ratnakaram
Comments: 7 Pages. OK
Aim and Objective: The aim and objective of this study were to develop a spectrophotometric method for the assay of selexipag (selective IP prostacyclin receptor agonist indicated for the treatment of pulmonary arterial hypertension) in pure and pharmaceutical formulations so that it will be an alternative quantitative method to chromatographic methods which require large quantities of organic solvents, where some are with hazardous and toxic properties. Materials and Methods: The method is based on the diazo coupling of selexipag with diazotized p-nitroaniline in alkaline medium to form a stable green-colored and water-soluble azo dye with a maximum absorption at 510 nm. Optimization of reaction conditions was carried out to get highly sensitive and stable colored complex. Results and Discussion: Beer’s law is obeyed over the concentration range of 2–12 μg/mL with a molar absorptivity of 3.33 × 104 L/mol/cm. The limit of detection was 0.35 μg/mL and limit of quantification was 1.0 μg/mL. The results demonstrated that the procedure is accurate, precise, and reproducible (relative standard deviation <2%). Conclusions: This method was tested and validated for various parameters according to the current ICH guidelines.
Category: Chemistry
[43] viXra:1905.0327 [pdf] submitted on 2019-05-19 02:22:38
Authors: Giri Prasad Gorumutchu, Venkata Nadh Ratnakaram, Sireesha Malladi
Comments: 7 Pages. OK
Aim: The objective of the current study is to develop a colorimetric method for the determination of mianserin, an antidepressant drug. Materials and Methods: Fast Sulphon Black F, an acidic dye was used to develop a soluble colored ion-pair complex. The complex was extracted into an organic solvent and absorbance was measured. Results: Reaction conditions were optimized to obtain a sensitive and stable chromophore (λmax 554 nm) in dichloromethane. Good linearity was observed for the calibration curve plotted in the studied concentration range (4–14 μg/mL) with regression analysis (r > 0.9997). High percentage recovery values (98.25–101.40) show that the method is accurate. Reproducibility of the method is evident from lower relative standard deviation (<2%) for both intra- and inter-day precision studies. Conclusions: The proposed method is validated as per the existing ICH guidelines. This method is simple as it does not require any pre-treatment process.
Category: Chemistry
[42] viXra:1905.0326 [pdf] submitted on 2019-05-19 02:34:18
Authors: Giri Prasad Gorumutchu, Venkata Nadh RATNAkaram
Comments: 6 Pages. OK
The present study is a first report on development of a spectrophotometric method for determination of selexipag (used to cure pulmonary arterial hypertension) in bulk and tablet formulation and its validation. The basis of the proposed method is formation of a chromophore (of λ max 600 nm) in presence of acidic ferric chloride by oxidative coupling reaction between selexipag and MBTH (3-methylbenzo-thiazolin-2-one hydrazone) solution. Regression analysis (r > 0.999) shows that the plotted calibration curve exhibits good linearity in the studied range of concentration (5 – 30 μg mL-1). As per the existing guidelines of ICH, various parameters of the method were tested for validation. Low values of R.S.D. (< 2%) were observed indicating that the proposed method is reproducible, accurate and precise.
Category: Chemistry
[41] viXra:1905.0325 [pdf] submitted on 2019-05-19 02:35:59
Authors: Sireesha Malladi, Venkata Nadh Ratnakaram, K. Suresh Babu, T. Pullaiah
Comments: 13 Pages. OK
Phtytochemical Library of Caralluma Genus
Category: Chemistry
[40] viXra:1905.0324 [pdf] submitted on 2019-05-19 02:37:23
Authors: Garbapu Suresh, Ratnakaram Venkata Nadh, Navuluri Srinivasu, Durgaprasad Yennity
Comments: 8 Pages. OK
A highly efficient and milder protocol for the syntheses of novel series of 2-aminothiazoles
bearing 5-methylisoxazoline and pyridine-piperazine hybrid molecules has been developed. The target
compounds 13a-e were screened for their in vitro cytotoxicity activity against various tumor cell lines
including MCF-7 (human breast adenocarcinoma), HCT-116 (colorectal carcinoma), Jurkat (human Tcell
leukemia) and THP-1 (human acute monocytic leukemia). The bioactive assay showed most of the
new compounds exhibited promising results in comparison with the parental Sunitinib. The synthesized
compounds could well be used in the future as lead anticancer drugs in drug development studies. The
synthesized compounds were fully characterized by IR, 1H NMR, 13C NMR, elemental analysis and
mass spectral data.
Category: Chemistry
[39] viXra:1905.0323 [pdf] submitted on 2019-05-19 02:39:52
Authors: 58.G. Venkata Narasimha Rao, Muralee Krishna, Ravi Kumar Bellam, R. Venkata Nadh
Comments: 10 Pages. OK
LC-MS compatible stability indicating RP-UPLC method for the estimation of ester prodrug of mycophenolic acid in injection formulation
Category: Chemistry
[38] viXra:1905.0322 [pdf] submitted on 2019-05-19 02:41:23
Authors: P.Vijetha, R. Venkata Nadh, K. Ramesh Naidu, T.Swapna Sundari
Comments: 3 Pages. OK
Most of the synthetic colours are carcinogenic. Many
natural colours are thought to play- a significant role in preventing
or delaying the onset of many diseases. Optimized conditions were
arrived for the extraction of plant based biocolours based on the
literature survey. In the present study, extraction of bixin from
annatto seeds was carried out using ethyl acetate and ethanol. A
pure bixin is obtained by precipitating from petroleum ether. A
simple method for preparing butter colour from annatto seeds is
tested using castor oil and groundnut seed oil. Lycopene was
extracted from tomatoes using ethyl acetate as a solvent and
further purified by successive recrystallisation from ethyl acetate
and ethanol. A stable oleoresin of lycopene was prepared in
soybean oil. Purity of extracted colours is established from spectral
studies.
Category: Chemistry
[37] viXra:1905.0321 [pdf] submitted on 2019-05-19 02:42:54
Authors: Vishnu Vardhan Reddy Beeram, Krupanidhi S, Venkata Nadh R
Comments: 8 Pages. OK
Rifampicin PLGA nanospheres are
formulated with a specific goal in order to decrease
the dose, adverse effects and to enhance targeted
drug delivery. Rifampicin nanospheres were
prepared and evaluated by emulsion solvent
evaporation method. In vivo bio distribution studies
reveal that there was a long term accumulation of
rifampicin nanospheres in the lungs over other
organs. The increase in Cmax values confirmed that
inhalable PLGA nanospheres are suitable for
targeting and providing sustained release of antitubercular
drugs to lungs. So inhalation is a
selected administration route of Rifampicin PLGA
nanospheres. The in vivo screening of M.
tuberculosis showed good activity as well as its
activity against multidrug-resistant M. tuberculosis
and against M. tuberculosis isolates in a
potentially latent state, makes Rifampicin PLGA
nanospheres as an attractive drug dosage form
for the therapy of tuberculosis. It can be concluded
that there is a significant potential for effective
oral delivery as well as nasal delivery of the
Nanospheres for the treatment of tuberculosis.
Category: Chemistry
[36] viXra:1905.0320 [pdf] submitted on 2019-05-19 02:44:25
Authors: Nukendra Prasad Nadella, Venkata Nadh Ratnakaram, N. Srinivasu
Comments: 11 Pages. OK
A methodical design-of-experiments were performed by applying quality-by-design concepts to establish
a design-space for simultaneous and rapid quantification of Carvedilol and Ivabradine by UPLC in the
presence of degradation products. Response-surface, central-composite design, and quadratic model
were employed for statistical assessment of experimental data using the Design-Expert software.
Response variables such as resolution and retention time were analyzed statistically for chromatographic
screening. During DoE study, various plots such as perturbation, contour, 3D and design-space plots were
considered for method optimization. The method was developed using C8 [100 � 2.1 mm, 1.8 μ] UPLC
column, mobile phase comprising 0.5% triethylamine buffer [pH 6.4] and acetonitrile in the ratio of 50:50
v/v, the flow rate of 0.4 mL minute−1 and UV detection at 285 nm for both Carvedilol and Ivabradine.
The method was developed with a short run time of two minutes. The method was found to be linear in
the range of 25.0–199.9 μg mL−1 and 8.9–21.3 μg mL−1 for Carvedilol and Ivabradine, respectively with a
correlation coefficient of 0.9998 in each case. The recovery values were found in the range of 99.7–100.8%
and 98.9–100.9% for Carvedilol and Ivabradine, respectively. The method was validated according to ICH
Q2 (R1) guidelines.
Category: Chemistry
[35] viXra:1905.0319 [pdf] submitted on 2019-05-19 02:46:27
Authors: Arunkumar Thiriveedhi, Ratnakaram Venkata Nadh, Navuluri Srinivasu, Kishore Kaushal3
Comments: 9 Pages. OK
Background: A new series of quinazoline linked chalcone conjugates were synthesized
and evaluated for their in vitro cytotoxicity.
Methods: The quinazoline-chalcone derivatives (13a-r) have been prepared by the Claisen-Schmidt
condensation of various substituted benzaldehydes (12a-r) with substituted l-(4-(3,4-
dihydroquinazolin-4-ylamino)phenyl)ethanone (11a-b) in the presence of aqueous NaOH. Three
potential compounds 13f, 13g and 13h exhibited cytotoxicity against leukemia (GI50 value of
1.07, 0.26 and 0.24 μM), Non-small lung (GI50 values of 2.05,1.32 and 0.23 μM), colon (GI50
values of 0.54, 0.34 and 0.34 μM) and breast (GI50 values of 2.17, 1.84 and 0.22 μM) cell line,
respectively.
Results and Conclusion: Based on these biological results, it is evident that compound 13h has the
potential to be considered for further detailed studies either alone or in combination with existing
therapies as potential anticancer agents.
Category: Chemistry
[34] viXra:1905.0318 [pdf] submitted on 2019-05-19 02:48:05
Authors: Arunkumar Thiriveedhi, Ratnakaram Venkata Nadh, Navuluri Srinivasu1, Kishore Kaushal3
Comments: 7 Pages. OK
Background: Now-a-days, the model of “hybrid drugs” has acquired recognition in
medicine due to their significant role in the treatment of different health problems.
Methods: We have synthesized new series of isoxazole-chalcone conjugates (14a-m) by the
Claisen-Schmidt condensation of suitable substituted acetophenones with isoxazole aldehydes (12a-d).
In vitro cytotoxic activity of the synthesized compounds was studied against four different selected
human cancer cell lines by using sulforhodamine B (SRB) method.
Results: The adopted scheme resulted in good yields of new series of isoxazole-chalcone
conjugates (14a-m). Potent cytotoxic activity was observed for compounds -14a, 14b, 14e, 14i, 14j
and 14k against prostate DU-145 cancer cell line.
Conclusion: The observed potent cytotoxic activities were due to the presence of 3,4,5-
trimethoxyphenyl group.
Category: Chemistry
[33] viXra:1905.0317 [pdf] submitted on 2019-05-19 02:49:37
Authors: Sireesha Malladi, Venkata Nadh Ratnakaram, K. Suresh Babu4, T. Pullaiah5
Comments: 15 Pages. OK
Caralluma lasiantha is used as a traditional medicine in India to heal body
heat and inflammations. In order to find out a scientific validation for the Indian
traditional knowledge, antibacterial activity of C. lasiantha extracts was studied
against inflammation causing bacteria (viz., Staphylococcus aureus, Escherichia coli,
Streptococcus Sp., Bacillus subtilis, Enterobacter aerogenes, Klebsiella pneumoniae)
along with other Gram-positive and Gram-negative bacteria. Solvents with different
polarity were used for extraction from dry roots and stems. Minimum inhibitory
concentrations (MIC) were also studied. Differential antibacterial activity was
exhibited by extracts and higher inhibition potential against Gram-positive bacteria
was explained. The observed antibacterial activities were correlated with the chemical
structures of phytochemicals present in C. lasiantha. Anti-inflammation activities
are related to C. lasiantha extracts through their antibacterial activities.
Category: Chemistry
[32] viXra:1905.0316 [pdf] submitted on 2019-05-19 02:52:32
Authors: S. Malladi, R.Venkata Nadh, K.Suresh Babu, P.Suri Babu
Comments: 9 Pages. OK
Synthesis and antibacterial activity studies of 2, 4- di substituted furan derivatives
Category: Chemistry
[31] viXra:1905.0315 [pdf] submitted on 2019-05-19 02:56:11
Authors: R. P. Mokkapati, V. N. Ratnakaram, J. S. Mokkapati
Comments: 12 Pages. OK
Abundantly available agricultural waste materials
(banana bunch, sorghum stem and casuarinas fruit) are
processed with negligible cost and are found to be highly
suitable as biosorbents for chromium(VI) removal from
aqueous environment due to high surface area and functional
groups of adsorbents. The equilibrium data have
been analyzed for the adsorbate–adsorbate/adsorbent
interactions and found to be fitted to the data in the order,
Hill–de Boer C Fowler–Guggenheim % Frumkin[Kiselev.
To determine the characteristic parameters for process
design, mass transfer studies have been carried out using
two-parameter isotherm models (Harkins–Jura, Halsey,
Smith, El-Awady and Flory–Huggins) and three-parameter
isotherm models (Redlich–Peterson and Sips) which are
applied to the experimental data. The fitness of the isotherms
describes that both mono- and multilayer adsorptions
occur in the present studied three biosorbents in
preference to the latter. The mechanism of adsorption has
been studied using diffusion kinetic models (viz. liquid film
diffusion, Dunwald–Wagner intra-particle diffusion model
and moving boundary model) and described the possibility
of diffusion in the order of banana bunch–stem powder[
sorghum stem powder[casuarinas fruit powder in
terms of diffusion coefficients. In essence of all the results,
the selected adsorbents can be used as a potential adsorbent
for the removal of Cr(VI) from aqueous solutions.
Category: Chemistry
[30] viXra:1905.0314 [pdf] submitted on 2019-05-19 02:59:03
Authors: Garbapu Suresh, Ratnakaram Venkata Nadh, Navuluri Srinivasu, Durgaprasad Yennity
Comments: 12 Pages. OK
A new and efficient synthetic route for dual-Src/Abl kinase inhibitor
dasatinib (Sprycel®), an anticancer drug, is described. This commercially
viable process yields dasatinib monohydrate free of potential impurities
with consistent yield of 68% in route A and 61% in route B with HPLC
purity >99.80% over four stages.
Category: Chemistry
[29] viXra:1905.0313 [pdf] submitted on 2019-05-19 03:01:17
Authors: Nukendra Prasad Nadella, Venkata Nadh Ratnakaram, N. Srinivasu
Comments: 11 Pages. OK
A systematic design-of-experiments was performed by applying quality-by-design concepts to determine
design space for rapid quantification of teriflunomide by the ultraperformance liquid chromatography
(UPLC) method in the presence of degradation products. Response surface and central composite
quadratic were used for statistical evaluation of experimental data using a Design-Expert software. The
response variables such as resolution, retention time, and peak tailing were analyzed statistically for the
screening of suitable chromatographic conditions. During this process, various plots such as perturbation,
contour, 3D, and design space were studied. The method was developed through UPLC BEH C18
2.1 � 100 mm, 1.7-μ column, mobile phase comprised of buffer (5 mM K2HPO4 containing 0.1%
triethylamine, pH 6.8), and acetonitrile (40:60 v/v), the flow rate of 0.5 mL min 1 and UV detection at
250 nm. The method was developed with a short run time of 1 min. Forced degradation studies revealed
that the method was stability-indicating, suitable for both assay and in-vitro dissolution of a drug product.
The method was found to be linear in the range of 28–84 μg mL 1, 2.8–22.7 μg mL 1 with a correlation
coefficient of 0.9999 and 1.000 for assay and dissolution, respectively. The recovery values were found in
the range of 100.1–101.7%. The method was validated according to ICH guidelines.
Category: Chemistry
[28] viXra:1905.0312 [pdf] submitted on 2019-05-19 03:03:10
Authors: Venkata Narasimha Rao G., Ravi B., Jalandhar D., Manoj P., R. Venkata Nadh
Comments: 16 Pages. OK
In the present study, two cancer therapeutic drugs (docetaxel and bortezomib) were separated from their
potential impurities on a chromatographic platform by utilizing CO2 gas (supercritical state) and quantified.
The chromatographic separations were achieved on two short columns BEH-2EP (100mm 3mm, 1.7 mm)
and CHIRALPAK AD-3 (100 mm 4.6 mm, 3 mm) for docetaxel and bortezomib, respectively. The present
work describes the role of organic modifiers in the separation of polar compounds by supercritical fluid
chromatography. The two new methods were fully validated in accordance with the current ICH
(International Council for Harmonization of technical requirements for pharmaceuticals for human use)
guidelines. The stability indicating power of the methods was demonstrated from the stress studies
conducted on the injection formulations of the two compounds. The methods are precise with % RSD of
0.4, linear with the correlation coefficient of r2 $ 0.999 and accurate in the range of 50–150% of the
target assay concentration. The two methods can be equally employed for the assay determination of
docetaxel and bortezomib APIs as well.
Category: Chemistry
[27] viXra:1905.0311 [pdf] submitted on 2019-05-19 03:04:38
Authors: Sireesha Malladi1, Venkata Nadh Ratnakaram, Suresh Babu K, Pullaiah T
Comments: 5 Pages. OK
Phytochemical screening of Caralluma lasiantha was carried out and one C21 pregnane steroid was isolated from chloroform extract. Based on spectroscopic studies (IR, 1H NMR, 13C NMR and ESI-MS) the isolated compound is 3b,14b-dihydroxy-14b-pregn-5-en-20-one which was earlier isolated from other species.
Category: Chemistry
[26] viXra:1905.0309 [pdf] submitted on 2019-05-19 04:52:21
Authors: Malladi S1, Ratnakaram VN, Suresh Babu K, Pullaiah T
Comments: 9 Pages. OK
Stigmasterol, a phytosteroid was isolated for the first time from C. lasiantha using n-hexane as a solvent. Stigmasterol was characterized on the basis of physical, chemical and spectral data (IR, 1H NMR, 13C NMR, 1HNMR, DEPT-45, 90 & 135, and MS) analysis as well as by comparing them to their literature data. A sequence of steps was adopted like saponification, fractional crystallization and gradient elution column chromatography to isolate stigmasterol because some phytosterols possess identical physical properties which makes it difficult to isolate the constituents.
Category: Chemistry
[25] viXra:1905.0308 [pdf] submitted on 2019-05-19 04:53:53
Authors: Sireesha Malladi1, Venkata Nadh Ratnakaram, Suresh Babu K3, Pullaiah T4
Comments: 7 Pages. OK
Caralluma is a genus used as traditional medicine. Caralluma lasiantha is medicinally important due
to existence of pregnane glycosides, which may possess various biological activities. This article thoroughly
reviewed about the usage of C. lasiantha in traditional medicinal system, phytochemicals present in it, profile
identification studies, anti-hyperglycemic effect, antibacterial, antifungal, cytotoxic and antioxidant activities.
Category: Chemistry
[24] viXra:1905.0307 [pdf] submitted on 2019-05-19 04:55:23
Authors: G. Venkata Narasimha Rao, B. Ravi1, M. Sunil Kumar1, P. Manoj1, R. Venkata Nadh
Comments: 14 Pages. OK
Plerixafor (PLX) injections are administered to patients with cancers of lymphocytes
(non-Hodgkin’s lymphoma) and plasma cells (multiple myeloma). The main
objective of the current study was to develop a short reverse phase chromatographic
method for the simultaneous quantification of PLX and its impurities, in an injection
formulation, to reduce the time required for these quality tests. Furthermore, the
present work describes the role of nonalkyl branched nonquaternary ion pair reagent
in improving the peak shape and reducing column equilibration time. The separation
of PLX and its related substances is pH dependent (optimum pH = 2.50) and was
achieved on an octadecylsilyl (C18) column. The method was validated for its intended
purpose in accordance with the current regulatory guidelines for validation. The
proposed method can be applied for quality control, release, and stability analyses of
active pharmaceutical ingredient, PLX, as well as finished products, PLX injections.
Category: Chemistry
[23] viXra:1905.0306 [pdf] submitted on 2019-05-19 04:57:15
Authors: Garbapu Suresh, Ratnakaram Venkata Nadh, Navuluri Srinivasu, Kishore Kaushal
Comments: 9 Pages. OK
A highly efficient and mild protocol for the syntheses of ethyl-3-
[7-benzyloxy-4-methyl-2-oxo-2H-8-chromenyl]-5-aryl-4,5-dihydro-4-
isoxazole carboxylates and ethyl-3-[7-benzyloxy-3-chloro-4-methyl-2-
oxo-2H-8-chromenyl]-5-aryl-4,5-dihydro-4-isoxazole carboxylates in
good yields via [3 þ 2] cycloaddition of in situ–generated nitrile
oxides from 7-benzyloxy-4-methyl-coumarin hydroxymoylchlorides
and 7-benzyloxy-3-chloro-4-methyl-coumarin hydroxymoylchlorides
respectively with ethyl-3-aryl prop-2-enoate has been developed.
The new compounds are screened for antibacterial activity.
Category: Chemistry
[22] viXra:1905.0305 [pdf] submitted on 2019-05-19 04:59:11
Authors: Mokkapati Ramya Prasanthi, Mokkapati Jayasravanthi, Ratnakaram Venkata Nadh, †
Comments: 10 Pages. OK
Removal of Cr(VI) by biosorption on two agro waste materials, casuarinas fruit powder (CFP) and sorghum
stem powder (SSP), has been investigated. The prepared adsorbent materials were characterized by SEM, EDX,
FTIR and BET. These biomaterials effectively removed Cr(VI) with a maximum removal of 93.35% and 63.75% using
15 gL−1 and 5 gL−1 of CFP and SSP, respectively, at 60 oC with 20mgL−1 initial Cr(VI) concentration in solution. In both
cases of adsorbents, kinetic data of adsorption fitted well in pseudo-second-order in terms of correlation coefficient
(R2). This helps in proposing the process of adsorption as chemical coordination, which is correlated with the thermodynamic
study results conducted at different values of temperature. Langmuir, Freundlich and D-R models were evaluated
for description of metal sorption isotherms. Values of coefficients of intra-particle diffusion and mass transfer have
also been determined at different values of temperature.
Category: Chemistry
[21] viXra:1905.0304 [pdf] submitted on 2019-05-19 05:01:07
Authors: Ramya Prasanthi Mokkapati1, Jayasravanthi Mokkapati, Venkata Nadh Ratnakaram
Comments: 10 Pages. OK
Three novel and distinct agricultural waste materials, viz., Casuarinas fruit powder (CFP), sorghum stem powder
(SSP) and banana stem powder (BSP) were used as low cost adsorbents for the removal of toxic copper(II) from
aqueous solutions. Acid treated adsorbents were characterized by SEM, EDX and FTIR. Different factors effecting
adsorption capacity were analyzed and the effi ciency order was BSP>SSP>CFP. Based on the extent of compatibility
to Freundlich/Langmuir/D-R/Temkin adsorption isotherm and different models (pseudo-fi rst and second order,
Boyd, Weber’s and Elovich), chemisorption primarily involved in the case of CFP and SSP, whereas, simultaneous
occurrence of chemisorption and physisorption was proposed in the case of BSP. Based on the observations, it was
proposed that three kinetic stages involve in adsorption process viz., diffusion of sorbate to sorbent, intra particle
diffusion and then establishment of equilibrium. These adsorbents have promising role towards removal of Cu(II)
from industrial wastewater to contribute environmental protection.
Category: Chemistry
[20] viXra:1905.0303 [pdf] submitted on 2019-05-19 05:02:43
Authors: Vishnu Vardhan Reddy Beeram1, Venkata Nadh R, Krupanidhi S1, Gnana Prakash K3
Comments: 8 Pages. OK
The emergence of multidrug-resistant TB (MDR-TB) against first-line drugs and extensively drug resistant TB (XDRTB)
due to misuse of second-line anti tubercular drugs (ATDs) is a further concern. Recommended treatment involves
long term and multiple drug therapy with severe side effects. Due to this concern nanoparticle-based systems
have significant potential for treatment and prevention of tuberculosis (TB) to overcome the need to administer
ATDs at high and frequent doses, would assist in improving patient compliance and circumvent hepatotoxic ity
and/or nephrotoxicity/ocular toxicity/ototoxicity associated with the prevalent first-line chemotherapy.
Nanostructured delivery systems constitute a wide range of systems varying from liposomes, micelles, micro- and
nanoemulsions, to polymeric nanoparticles (PNPs ) and solid lipid nanoparticles (SLNs). Pulmonary administration
of inhaled nanoparticles in the form of dry powder inhalers offer particular advantages for pulmonary administration
of anti tubercular drugs (ATDs). Present review comprehensively about different approaches of nanobased
drug delivery, devises and techniques for pulmonary delivery of nanoparticle encapsulated ATD.
Category: Chemistry
[19] viXra:1905.0302 [pdf] submitted on 2019-05-19 05:09:31
Authors: Venkata Narasimha Rao Ganipisetty, D Jalandhar, G. Gnanadev, P. Manoj, R. Venkata Nadh
Comments: 9 Pages. OK
In the present study 12 impurities of bisoprolol fumarate (BISO) and hydrochlorothiazide (HCTZ) were
separated simultaneously in a single HPLC method. Out of these 12 impurities, five are potential
degradants, which are validated as per The International Council for Harmonisation of Technical
Requirements for Pharmaceuticals for Human Use (ICH) guidelines. As the two active drug substances
BISO and HCTZ have different solubilities and polarities, the most critical parameters in resolving the
components from each other are pH, temperature, and solvents. The method is precise (RSD < 1.0%),
accurate, linear (r2 > 0.999), robust, and stability indicating in the range of limit of quantification (LOQ)
to 150%. The HPLC method is then migrated to ultra-performance liquid chromatography (UPLC) to
further reduce the run time and solvent consumption, and increase the sample throughput.
Category: Chemistry
[18] viXra:1905.0301 [pdf] submitted on 2019-05-19 05:10:49
Authors: R. Venkata Nadh, B. Syama Sundarb, P. S. Radhakrishnamurtic
Comments: 6 Pages. OK
Abstract—Kinetics of uncatalyzed and ruthenium(III) catalyzed oxidation of monoethanolamine by N-bromosuccinimide
(NBS) has been studied in an aqueous acetic acid medium in the presence of sodium acetate
and perchloric acid, respectively. In the uncatalyzed oxidation the kinetic orders are: the first order in NBS,
a fractional order in the substrate. The rate of the reaction increased with an increase in the sodium acetate
concentration and decreased with an increase in the perchloric acid concentration. This indicates that free
amine molecules are the reactive species. Addition of halide ions results in a decrease in the kinetic rate,
which is noteworthy. Both in absence and presence of a catalyst, a decrease in the dielectric constant of the
medium decreases the kinetic rate pointing out that these are dipole—dipole reactions. A relatively higher
oxidation state of ruthenium i.e., Ru(V) was found to be the active species in Ru(III) catalyzed reactions. A
suitable mechanism consistent with the observations has been proposed and a rate law has been derived to
explain the kinetic orders.
Category: Chemistry
[17] viXra:1905.0300 [pdf] submitted on 2019-05-19 05:12:31
Authors: Y. Lakshman Kumara, R. Venkata Nadh, P. S. Radhakrishnamurti
Comments: 8 Pages. OK
Role of added chloride ions on the shift of reaction pathway of oxidation of aromatic ketones (acetophenone,
desoxybenzoin) by dichloroisocyanuric acid (DCICA) was studied in aqueous acetic acid—perchloric
acid medium. Participation of enolic and protonated forms of ketones in the rate determining steps is
manifested from zero and first orders with respect to the oxidant in absence and presence of added chloride
ions, respectively. Positive and negative effects of acid and dielectric constant on the reaction rate were
observed. The observations deduce plausible mechanisms involving (i) rate-determining formation of enol
from the conjugate acid of the ketone (SH+) in the absence of added chloride ions and (ii) rapid formation of
molecular chlorine species from HOCl (hydrolytic species of DCICA) in the presence of added chloride ions,
which then interacts with SH+ in a rate-determining step prior to the rapid steps of product formation. The
order of Arrhenius parameters substantiate the proposed plausible mechanisms based on order of reactants
both in presence and absence of added chloride ions.
Category: Chemistry
[16] viXra:1905.0299 [pdf] submitted on 2019-05-19 05:14:22
Authors: Y. Lakshman Kumara, R. Venkata Nadh, P. S. Radhakrishnamurtia
Comments: 9 Pages. OK
Kinetics of ruthenium(III) catalyzed oxidation of biologically important sugar alcohols (myo-inositol,
D-sorbitol, and D-mannitol) by dichloroisocyanuric acid was carried out in aqueous acetic acid—perchloric
medium. The reactions were found to be first order in case of oxidant and ruthenium(III). Zero order
was observed with the concentrations of sorbitol and mannitol whereas, a positive fractional order was found
in the case of inositol concentration. An inverse fractional order was observed with perchloric acid in oxidation
of three substrates. Arrhenius parameters were calculated and a plausible mechanism was proposed.
Category: Chemistry
[15] viXra:1905.0298 [pdf] submitted on 2019-05-19 05:16:03
Authors: Ramya P.M., Jayasravanthi M., Dulla B.J., Venkata N.R.
Comments: 10 Pages. OK
The utilization of
t hree novel and distinct agricultural waste materials, namely c asuarina fruit powder
CFP s orghum stem powder SSP ) and b anan a stem powder ( as low cost adsorbents for reducing
chemical oxygen demand ( COD levels of coffee industry waste water has been examined. Prepared
adsorbents were characteriz ed by scanning electron microscopy ( SEM), Energy dispersive x ray
spectros copic ( and Fourier Transform Infrared Spectroscopy The effects of parameters like
adsorbent dose, pH, temperature agitation rate and time of adsorption on the reduction of COD levels
were analyzed for each adsorbent individually and the efficiency order is CFP>SSP>BSP. Based on the
extent of compatibility to Freundlich/ Langmuir adsorption isotherm and different models ( pseudo first
order and second order , Boyd, Weber’s and Elovich), simultaneous occurrence of chemis orption and
physi sorption was proposed. Based on the observations, it is proposed that three kinetic stages involve in
adsorption process viz., diffusion of sorbate to sor bent, intra particle d iffusion and then establishment of
equilibrium. As these three adsorbents exhibit adsorption capacity more than 80%, the adsorbents
prepared from agricultural wastes have promising role towards reduction of COD from industrial
waste water to contribute envi ronmental protection .
Category: Chemistry
[14] viXra:1905.0297 [pdf] submitted on 2019-05-19 05:18:13
Authors: R.Venkata Nadh, M.Sireesha
Comments: 9 Pages. OK
The kinetics of Ru(III) catalysed and uncatalysed oxidation of DL-alanine by N-bromosuccinimide (NBS) was studied in aqueous acetic acid and in the presence of perchloric acid and Hg (II). In both Ru(III) catalysed and uncatalysed oxidations, the kinetic orders were: first order in NBS, fractional order in substrate. The rate of the reaction decreased with the increase in perchloric acid concentration and addition of halide ions. The reactions were of fractional order with respect to Ru (III). Addition of Os(VIII) had no effect on the rate of oxidation of DL-alanine by NBS. The presence of catalysis with Ru (III) and the absence of catalysis with Os(VIII) in NBS oxidations was traced to different factors. A factor other than complexation could be a more powerful oxidant species like Ru (V) which accelerates the NBS oxidations. The effect of temperature was also investigated. By varying the solvent composition it was found that the reaction rate decreased with the decrease in dielectric constant of the solvent. All kinetic features were explained by postulating suitable mechanisms and rate laws.
Category: Chemistry
[13] viXra:1905.0296 [pdf] submitted on 2019-05-19 05:20:14
Authors: Y. Lakshman Kumara, R. Venkata Nadh, P. S. Radhakrishnamurtia
Comments: 8 Pages. OK
Effect of added chloride ions on kinetics and pathway of reaction between cyclic ketones (five to
eight membered rings) and dichloroisocyanuric acid (DCICA) was studied in aqueous acetic acid—perchlo
ric acid medium. Formation of aliphatic dicarboxylic acids as the end products demonstrates the ring cleav
age oxidation. Positive effect of acid and negative effect of dielectric constant on the reaction rate reveals a
interaction between positive ion (oxidant in the form of H2OCl+) and dipolar substrate molecule. Zero and
first orders by oxidant in absence and presence of added chloride ions illustrates the participation of substrate
as enolic form of ketone and protonated ketone, respectively, in the rate determining steps. The observed
order of reactivity of cyclic ketones (cyclohexanone > cyclooctanone > cyclopentanone > cycloheptanone)
was explained on the bases of ring strain, change of hybridization and conformational considerations. The
envisaged plausible mechanism based on order of reactants in presence and absence of added chloride ions
was substantiated by the order of Arrhenius parameters.
Category: Chemistry
[12] viXra:1905.0295 [pdf] submitted on 2019-05-19 05:22:25
Authors: Y. Lakshman Kumar, R. Venkata Nadh, P.S. Radhakrishnamurti
Comments: 8 Pages. OK
Kinetics of reactions of enolisable ketones (S = acetone/2-butanone) with dichloroisocyanuric
acid (DCICA) were studied in aqueous acetic acid and perchloric acid media in absence and presence of added
chloride ions. The reactions were found to be pseudo zero order and pseudo first order on [DCICA] in absence and
presence of chloride ions respectively. Both in presence and absence of chloride ions, first order and fractional
order in substrate and perchloric acid were observed respectively. An increase in the rate of reaction was observed
with an increase in chloride ion concentration as well as acetic acid composition. The results were interpreted in
terms of probable mechanisms involving (i) rate-determining enol formation from the conjugate acid of the ketone
(SH+) in the absence of added chloride ions and (ii) rate-determining interaction of SH+ with the most effective
molecular chlorine species produced by the hydrolysis of DCICA (rather than a rate-determining interaction of
enol with chlorine) in the presence of added chloride ions, prior to the rapid steps of product formation.
Category: Chemistry
[11] viXra:1905.0294 [pdf] submitted on 2019-05-19 05:24:35
Authors: Venkata Narasimha Rao Ganipisetty, a B. Ravi, a Ch. Rajsekhara Reddy, a RajKumar Gurjar, a P. Manoj, a R. Venkata Nadh, Gnana dev Gudipatia
Comments: 6 Pages. OK
In the present study, supercritical fluid (carbon dioxide) chromatographicmethods were developed and validated
for the quantitative assay determination of two cancer therapeutic substances, fulvestrant and azacitidine, using a
UPC2 system. Fulvestrant was separated from six potential impurities, while impurities of azacitidine were
separated using a 150 mm 4.6 mm, I.D., a chiral column and 5 mm, particle size. Both drugs were analysed
simultaneously in a single sequence using multiple channels in the system and respective methods. These
new methods were validated for their intended purpose in accordance with the current ICH guidelines. The
method exhibited excellent intra- and inter-day precision. A precision with RSD 1% and 1.6% was achieved for
fulvestrant and azacitidine, respectively. A linear relationship r2 > 0.999 was achieved between the
concentration and detector response over a range of 25–150% of the target concentrations for both
compounds. The two compounds were well quantified from their unspecified impurities obtained from stress
studies. The method can be employed for routine quality control testing and stability analysis.
Category: Chemistry
[10] viXra:1905.0293 [pdf] submitted on 2019-05-19 05:26:34
Authors: Kiran Kumar KATARE, Venkata Nadh RATNAKARAM, Nagoji K.E.V.
Comments: 8 Pages. OK
Using gemcitabine hydrochloride as an internal standard, an
accurate, sensitive, precise and robust reverse phase high performance
liquid chromatographic (RP-HPLC) method has been developed
for the estimation of bendamustine in bulk and dosage forms. The
proposed method was validated as per the ICH guidelines (2005)
and can be applied for the quantitative analysis of bendamustine
in bulk and pharmaceutical dosage forms. The chromatographic
separation was performed on ODS C-18 RP column (4.6 mm i.d
x 250 mm) at ambient temperature using a mixture of methanol :
water (50:50 v/v) as a mobile phase and at a flow rate of 1.0 ml/
min, while UV detection was performed at 232 nm. The retention
times of gemcitabine and bendamustine were in the ranges of
6.647–6.797 and 11.66–12.49 minutes, respectively. The method
was found to be linear in the range of 1 – 10 μg/ml. The LOD and
LOQ for bendamustine were found to be 0.0422 and 0.1279 µg/ml
respectively. Analytical recovery varied from 98.9% to 99.13%. The
percentage RSD for precision and accuracy of the method was found
to be less than 2%.
Category: Chemistry
[9] viXra:1905.0292 [pdf] submitted on 2019-05-19 05:29:59
Authors: H. Sudhakar1, G. Pavana Kumari2, R. Venkata Nadh, Naveen Mulakayala
Comments: 6 Pages. OK
A new method for the synthesis of N-alkyl anilines from phenols using silica sulfuric acid as a catalyst is described via smiles rearrangement. The synthesized anilines are handy intermediates in the organic synthesis.
Category: Chemistry
[8] viXra:1905.0291 [pdf] submitted on 2019-05-19 05:31:34
Authors: Katare Kiran Kumar1, Ratnakaram Venkata Nadh, K.e.v. Nagoji3
Comments: 6 Pages. OK
The present study is aimed to develop visible spectrophotometric methods for the
determination of Bendamustine hydrochloride. The developed methods involve the formation of
chloroform extractable colored ion-association complexes of Bendamustine hydrochloride with
tropaeolineo-oo (Method A) and Alizarin Red S (Method B). The chloroform extracted coloured
complexes showed absorbance maxima at wavelengths 480 and 460nm in methods A and B
respectively. Beer’s law obeyed in the concentration range of 2.5–12.5 μg/mL in both the cases.
Correlation coefficients were found to be 0.9991 and 0.9998 for methods A and B respectively. In
addition molar absorptivity, Sandell sensitivity and the optimum conditions for quantitative analysis
of the Bendamustine hydrogenchloride were determined. The developed ion-association complex
methods were rapid, simple and economically viable compared to other reported analytical methods
which require expensive instruments and are not available in common laboratories. Thus the
proposed methods for Bendamustine determination in bulk and pharmaceutical formulations can
be used in commercial laboratories.
Category: Chemistry
[7] viXra:1905.0290 [pdf] submitted on 2019-05-19 05:33:49
Authors: S.S. Muvvala1, V.N. Ratnakaram
Comments: 6 Pages. OK
Many of the classical synthetic methodologies have broad scope but generate copious amounts of waste. The
chemical and pharmaceutical industries have been subjected to increasing pressure to minimize or, preferably, eliminate
this waste. In the present study a series of some newer 1,2,3–benzotriazole derivatives were synthesized under
ultrasonicated and solvent–free conditions. Newer “1–(1H–benzo[d][1,2,3]triazole–1–carbonyl) derivatives” (5A – 5P)
were synthesized from “1H–benzo[d][1,2,3]triazole” (1) by optimizing the reaction conditions. The resulting products
were isolated and characterized by spectral studies. The anti bacterial activities of these compounds were screened in
vitro against different strains of bacteria i.e. Gram negative organism (Pseudonomous aureginosa, MTCC – 1035) and
Gram positive organisms (Bacillus cereus, MTCC – 430, Bacillus subtilis, MTCC – 441, Staphylococcus aureus,
MTCC – 737, Staphylococcus epidermidis, MTCC – 3086) by paper disc diffusion method. Some of the synthesized
compounds showed significant activity against various bacteria.
Category: Chemistry
[6] viXra:1905.0289 [pdf] submitted on 2019-05-19 05:35:10
Authors: Y. Lakshman Kumar, R. Venkata Nadh, P. S. Radhakrishnamurti
Comments: 5 Pages. OK
Abstract—In the oxidation of Dsorbitol and Dmannitol by potassium periodate in alkaline mediam, sub
strate inhibition was observed with both the substrates, i.e., a decrease in the rate of the reaction was observed
with an increase in the concentration of substrate. The substrate inhibition was attributed to the formation of
stable complex between the substrate and periodate. The reactions were found to be first order in case of peri
odate and a positive fractional order with hydroxide ions. Arrhenius parameters were calculated for the oxi
dation of sorbitol and mannitol by potassium periodate in alkali media.
Category: Chemistry
[5] viXra:1905.0288 [pdf] submitted on 2019-05-19 05:36:32
Authors: K. Suresh Babu1, Sireesha Malladi2, R. Venkata Nadh, S. Siva Rambabu
Comments: 16 Pages. OK
Aims: To find out a scientific validation for the traditional knowledge of tribals of Chittoor
District, India for their usage of Caralluma umbellata Haw to cure stomach disorder and
pain.
Methodology: Antibacterial activity of Caralluma umbellata Haw was studied on a few
Gram positive and Gram negative bacteria. The dry roots and stems were extracted using
hexane, benzene, diethyl ether, chloroform, acetone and methanol and were tested for
their antibacterial activity.
Results: The root extracts were found to be effective against most of the organisms than
the stem extracts. The extracts were highly effective against Bacillus subtillis, Bacillus
cereus, Escherichia coli and Staphylococcus aureus. Chloroform extracts of both roots and
stems exhibited good antibacterial activity againstConclusion: The demonstration of antibacterial activity of C. umbellata against Gram
positive (B.subtilis and B.cereus) and Gram negative bacteria (E.coli) provides the scientific
basis for its use in the traditional treatment of stomach disorder.
Category: Chemistry
[4] viXra:1905.0287 [pdf] submitted on 2019-05-19 05:37:40
Authors: Muvvala Subrahmanya Sudhir1, Ratnakaram Venkata Nadh
Comments: 8 Pages. OK
A simple, precise, accurate, high reproducible and economical visible spectrophotometric method of analysis for the synthesized rasagiline hemitartrate was developed and validated. The proposed method involves diazotization of sulphanilic acid under acidic conditions in presence of sodium nitrite, followed by its coupling with rasagiline in alkaline medium. The absorption spectra of the yellow colored chromophore formed between rasagiline and positive diazonium ion has absorption maximum at 440 nm. The linear regression analysis data for the calibration plot showed good linear relationship (r = 0.99937) with in the concentration range of 0 – 10 μg mL-1. The limit of detection and limit of quantitation were found to be 0.033 μg mL-1and 0.1 μg mL-1 respectively. This method was tested and validated for various parameters according to ICH guidelines. The results demonstrated that the procedure is accurate, precise and reproducible (R.S.D. < 2 %).
Category: Chemistry
[3] viXra:1905.0286 [pdf] submitted on 2019-05-19 05:40:04
Authors: Venkata Narasimha Rao Ganipisetty, a Jalandhar D, a Gnana dev G, a Rajendar Bandari, a Manoj P, a Dhananjay Da, Venkata Nadh R
Comments: 6 Pages. OK
The present study reports the development and validation of a stability indicating assay method for
clofarabine in injection on a UPC2 (ultra performance convergence chromatography) instrument,
which utilizes the unrealized potential of supercritical fluid chromatography. The use of UPC2 provides
a single viable technique that is a sustainable, reduced cost, and green technology that lowers the use
of organic solvents. Based on this advantage, we explored a simple and robust method in order to
increase sample throughput and productivity to quantify clofarabine in the presence of its potential
impurities and other degradants. The separation was achieved on a BEH-2-ethyl pyridine (BEH 2EP)
column (100 mm 3.0 mm I.D. with an average pore diameter of 1.7 mm) by using methanol as a cosolvent
and carbon dioxide as a mobile phase in the ratio of 30 : 70. The detection is carried out at a
wavelength of 254 nm. We are able to achieve the separation of clofarabine from its potential
impurities and other degradants in less than 6 minutes with a low amount of solvent consumption. The
new method is validated in accordance with the ICH-guidelines and exhibited good intra- and inter-day
precision, accuracy and linearity (r2 $ 0.999) over a range of 50% to 150% of target concentration.
Category: Chemistry
[2] viXra:1905.0285 [pdf] submitted on 2019-05-19 05:42:03
Authors: Ganipisetty Venkata Narasimha Rao, a G. Gnanadev, a Bellam Ravi, a D. Dhananjaya, a P. Manoj, a B. Indua, R. Venkata Nadh
Comments: 6 Pages. OK
UltraPerformance convergence chromatography (UPC2) is a new category of separation science which
utilizes the unrealized potential of the supercritical chromatography phenomenon. UPC2 is a standalone,
viable technique that is cost effective, sustainable, and uses green technology that lowers the use
of organic solvents. Based on this advantage, we explored a simple and robust supercritical liquid-based
UPC2 method in order to increase sample throughput and productivity to quantify the diastereomers of
fulvestrant. The two isomers of fulvestrant were well separated on a chiral column (150 mm 4.6 mm,
I.D.) by applying a mixture of methanol and acetonitrile (9.5 : 0.5) as the co-solvent of the mobile phase
of carbon dioxide (75%). The detection was carried out at 280 nm. We were able to achieve a threefold
reduction in retention with an isocratic mode as compared to the United States Pharmacopoeias
(USP) normal phase method. This new method was validated in accordance with the ICH guidelines; it
exhibited good intra- and inter-day accuracy, precision, and the results were linear over a range of 25%
to 150% of the target concentration. The method could be successfully applied for the determination of
the diastereomeric ratio of fulvestrant as an API and in fulvestrant injectable finished products.
Category: Chemistry
[1] viXra:1905.0281 [pdf] submitted on 2019-05-19 05:50:15
Authors: Muvvala S Sudhir, Ratnakaram V Nadh
Comments: 9 Pages. OK
A simple, sensitive, precise, accurate and economical spectrophotometric method of analysis for lurasidone in bulk form was developed and validated. The method employed acetonitrile as solvent and the drug shows maximum absorbance at 263 nm. The absorbance was found to increase linearly with increasing concentration of lurasidone, which is corroborated by the calculated correlation coefficient value (r2 = 0.999). The linear regression analysis data for the calibration plot showed good linear relationship with in the concentration range of 10 – 60 μg/ml. The limit of detection and limit of quantitation were found to be 1.25316 μg/ ml and 3.797468 μg /ml respectively. This method was tested and validated for various parameters according to ICH guidelines. The results demonstrated that the procedure is accurate, precise and reproducible (R.S.D. < 2 %).
Category: Chemistry
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