Development of a validated RP-HPLC assay method for quantitative separation of Teriflunomide and its process-related impurities in bulk drugs Bhagavan Rajesh Babu Koppisetty, Rajendra Prasad Yejella, A. Krishna Manjari Pawar, Srinivasa Rao Yarraguntla, Varaprasada Rao Kollabathula, Vasudha Dadi, Challa Gangu Naidu Journal of Applied Pharmaceutical Science, 2023 Development and validation of a stability indicating related substances of Opicapone by reverse phase high performance liquid chromatography and its degradationRamachandran Dittakavi, Neeharika Tirumalasetty
THE DEVELOPMENT AND VALIDATION OF A FAST STABILITY INDICATING RP-HPLC METHOD FOR QUANTIFICATION OF LUMEFANTRINE AND ITS ORGANIC IMPURITIES USING CENTRAL COMPOSITE EXPERIMENTAL DESIGN TARAKA RAMESH G., Y. RAJENDRA PRASAD International Journal of Applied Pharmaceutics, 2023 Objective: The objective of the present study was to develop and validate a stability indicating RP-HPLC method for Lumefantrine (LF) and its organic impurities using a central composite design (CCD). Methods: A specific, simple quality control friendly isocratic elution method using reverse phase HPLC was developed for quantification of Lumefantrine (LF) and its organic impurities at a wavelength of 265 nm. The chromatographic separation was achieved on the column of Thermo Hypersil ODS C18 (150x4.6 mm, 3µ) with a buffer containing 0.1percent formic acid and acetonitrile 10:90 v/v as a mobile phase with a flow rate of 1.6 ml/min at 35 °C with a run time of 10 min. Based on the preliminary trials, CCD was employed to check the effect of independent variables such as Acetonitrile ratio (A), Flow rate (B), and Column oven temperature (C). While resolution between Lumefantrine (LF) and Impurity-A (X1), Impurity-A and Impurity-B (X2), and Plate count of Lumefantrine (LF) (X3) were considered as dependent variables and statistical evaluation performed by using design expert software. The optimized conditions were validated as per ICH guidelines. Results: The retention time of LF and its organic impurities were 1.9 min, 3.0, 4.5, and 6.4 min, respectively. Design space was established and desirability was found. LOD and LOQ for the Lumefantrine (LF) and its impurities were established with respect to test concentration. The plotted calibration curves were linear with a regression coefficient of R2>0.99, indicating that the linearity was within the limit. As a part of method validation, the parameters like Specificity with forced degradation, Linearity, Precision, Accuracy, Ruggedness, and Robustness were determined and the results were found to be within the allowable limits. Conclusion: The method developed and validated was found to be suitable for routine analysis and to be used for the measurement of Lumefantrine and its impurities. Since there is no stability indicating the RP-HPLC method with design space was reported in the literature, there is a need to develop quantitative methods under different conditions to achieve improvement in specificity and selectivity.
UTILITY OF QUALITY BY DESIGN APPROACH IN RP-HPLC METHOD DEVELOPMENT FOR QUANTIFICATION OF LAMIVUDINE AND EFFAVIRENZ IN COMBINATION FORMULATION Bhagavan Rajesh Babu KOPPİSETTY, Prof. Y. Rajendra PRASAD, Krishna Manjari Pawar AMGOTH, Srinivasa Rao YARRAGUNTLA, Vasudha DADI, Hemant Kumar TATAPUDI Ankara Universitesi Eczacilik Fakultesi Dergisi, 2023 Objective: For the measurement of lamivudine(LAM) and effavirenz (EVZ) in combination formulation, a uncomplicated and reliable liquid chromatographic approach has been proposed.
 Material and Method: Multivariate optimization of the RP-HPLC method, experimental conditions were accomplished using the design of experiments (DoE). The crucial method parameters were determined by a risk assessment. The mathematical models were created using three independent variables: percentage of acetonitrile, percentage of methanol, and buffer pH. The impacts of these independent elements were thoroughly investigated using the central composite design (CCD), which was utilized to analyze the response surface methodology. 
 Result and Discussion: The LAM and EVZ retention time and resolution were both concurrently optimized using the desirability function. Acetonitrile, methanol, and phosphate buffer (pH 7.0) in the proportions of 40:20:40 v/v each were used in the optimized and anticipated data from the contour diagram, with detection occurring at a wavelength of 215 nm. Baseline separation of both pharmaceuticals with high resolution and a run time of under 6 minutes was accomplished under these ideal conditions. The validated test parameters followed ICH recommendations. As a consequence, the findings demonstrated that the Quality by Design methodology could be successfully used to optimize the RP-HPLC technique for the concurrent quantification of LAM and EVZ.
Antitubercular activity assessment of fluorinated chalcones, 2-aminopyridine-3- carbonitrile and 2-amino-4H-pyran-3- carbonitrile derivatives: In vitro, molecular docking and in-silico drug likeliness studies Surendra Babu Lagu, Rajendra Prasad Yejella, Srinath Nissankararao, Richie R. Bhandare, Venu Sampath Golla, Bontha Venkata Subrahmanya Lokesh, M. Mukhlesur Rahman, Afzal Basha Shaik Plos One, 2022 A series of newer previously synthesized fluorinated chalcones and their 2-amino-pyridine-3-carbonitrile and 2-amino-4H-pyran-3-carbonitrile derivatives were screened for their in vitro antitubercular activity and in silico methods. Compound 40 (MIC~ 8 μM) was the most potent among all 60 compounds, whose potency is comparable with broad spectrum antibiotics like ciprofloxacin and streptomycin and three times more potent than pyrazinamide. Additionally, compound 40 was also less selective and hence non-toxic towards the human live cell lines-LO2 in its MTT assay. Compounds 30, 27, 50, 41, 51, and 60 have exhibited streptomycin like activity (MIC~16–18 μM). Fluorinated chalcones, pyridine and pyran derivatives were found to occupy prime position in thymidylate kinase enzymatic pockets in molecular docking studies. The molecule 40 being most potent had shown a binding energy of -9.67 Kcal/mol, while docking against thymidylate kinase, which was compared with its in vitro MIC value (~8 μM). These findings suggest that 2-aminopyridine-3-carbonitrile and 2-amino-4H-pyran-3-carbonitrile derivatives are prospective lead molecules for the development of novel antitubercular drugs.
Exploration of Fulvic Acid as a Co-Former in Crystal Engineering Kattamanchi Gnananath, Kolli Prabhanjan Kumar, Yejella Rajendra Prasad, Kalakonda Sri Nataraj, Mohamad Taleuzzaman, Mohammad Javed Ansari, Mohd. Aamir Mirza Separations, 2022 The aim of the project was to investigate Peat-derived Fulvic acid for its propensity to form co-crystals with quercetin and curcumin and characterize it by using different analytical techniques. The formation of co-crystals generally enhances water solubility and the overall bioavailability of molecules. Co-crystals were synthesized using a 1:1 stoichiometric ratio of fulvic acid with quercetin and curcumin, respectively, using solvent crystallization techniques taking tetrahydrofuran and water in a 1:1 v/v ratio. The co-crystals were characterized by spectroscopic methods, FTIR and Differential scanning calorimetry. Further confirmation was made by morphological studies using SEM. A structural analysis was also carried out, using 13C solid-state NMR analysis. The studies confirmed the formation of semi crystalline forms. Furthermore, the saturation solubility displayed the enhancement in solubility of up to 10, 5-folds for Quercetin and Curcumin, respectively. The in vitro dissolution results showed that T50% was achieved within 30 min for both the drugs. The literature supports that the nutraceutical co-crystals offer advantages, particularly in the improvement of biopharmaceutical properties and addressing the challenges of the lab and manufacturing scale process. Both the semi crystalline powders exhibited enhanced solubility and a better dissolution profile.
Synthesis, Anticancer and Antiviral Activity Studies of 1,3,4-Oxadiazoles: A Review K. DEVI, A. SRINIVASA RAO, Y. RAJENDRA PRASAD, K. RAJU, D. GEETA MOUNIKA Asian Journal of Chemistry, 2022 1,3,4-Oxadiazole is a five membered heterocyclic nucleus and a versatile lead structure, where its derivatives showed broad and potent biological functions especially as anticancer and antiviral agents which are associated with various mechanisms such as inhibition of different enzymes, kinases and growth factors. The present review summarizes various synthetic procedures and highlights the targeted inhibitory activities of 1,3,4-oxadiazoles as potential anticancer and antiviral agents along with their structure activity relationship. Molecular modeling and pharmacokinetic studies on 1,3,4-oxadiazoles proved a change in their polarity, flexibility and metabolic stability led to their improved biological activity potential. Among all the substituted 1,3,4-oxadiazoles, the mono- and 2,5-disubstituted derivatives showed considerable biological activities especially as anticancer and antiviral agents. Hence, scientists/researchers considered these as future lead molecules to treat cancer and viral infections along with other diseases. In future, the oxadiazole motif is likely to be incorporated in various other therapeutic molecules.
Sekikaic acid modulates pancreatic β-cells in streptozotocin-induced type 2 diabetic rats by inhibiting digestive enzymes Vinay Bharadwaj Tatipamula, Satya Sowbhagya Priya Annam, Ha Thi Nguyen, Haritha Polimati, Rajendra Prasad Yejella Natural Product Research, 2021 The antioxidant and antidiabetic effects of sekikaic acid (SA) were investigated using in vitro and in vivo study models. SA possessed good antioxidant activity as assessed through hydroxyl radicals (IC50 value = 41.5 µg/mL) and ferric ions assay (IC50 value = 42.0 µg/mL). SA exhibited stronger α-glucosidase and α-amylase inhibition than that of aldose-reductase and protein tyrosine phosphatase 1B. The hypoglycemic activity of SA caused significant reduction of plasma glucose levels in normal and glucose loaded rats. The anti-hyperglycemic activity of SA (2 mg/Kg body weight) was indicated by the reduction of blood glucose by 44.17 ± 3.78% in the third week in streptozotocin-induced diabetic rats. The hypolipidaemic action of SA was evident by the significant decrease in the levels of low-density lipoprotein, total cholesterol, and total glycerides. Histologically, the pancreas of the treated groups showed significant regeneration of the pancreatic β-cells compared to diabetic control, possibly due to the inhibition of digestive enzymes.
Design, synthesis, and antibacterial and antifungal activities of novel trifluoromethyl and trifluoromethoxy substituted chalcone derivatives Surendra Babu Lagu, Rajendra Prasad Yejella, Richie R. Bhandare, Afzal B. Shaik Pharmaceuticals, 2020 Despite the availability of many drugs to treat infectious diseases, the problems like narrow antimicrobial spectrum, drug resistance, hypersensitivities and systemic toxicities are hampering their clinical utility. Based on the above facts, in the present study, we designed, synthesized and evaluated the antibacterial and antifungal activity of novel fluorinated compounds comprising of chalcones bearing trifluoromethyl (A1–A10) and trifluoromethoxy (B1–B10) substituents. The compounds were characterized by spectroscopic techniques and evaluated for their antimicrobial activity against four pathogenic Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Escherichia coli and Bacillus subtilis) bacterial and fungal (Candida albicans and Aspergillus niger) strains. In this study, the compounds with trifluoromethoxy group were more effective than those with trifluoromethyl group. Among the 20 fluorinated chalcones, compound A3/B3 bearing an indole ring attached to the olefinic carbon have been proved to possess the most antimicrobial activity compared to the standard drugs without showing cytotoxicity on human normal liver cell line (L02). Further, the minimum inhibitory concentration (MIC) for A3/B3 was determined by serial tube dilution method and showed potential activity. These results would provide promising access to future study about the development of novel agents against bacterial and fungal infections.
Development and validation of a stability indicating rp-hplc method for simultaneous estimation of teneligliptin and metformin Rajani VETAPALEM, Rajendra Prasad YEJELLA, Lakshmana Rao ATMAKURI Turkish Journal of Pharmaceutical Sciences, 2020 OBJECTIVES: The main objective of the present work is to develop a simple, precise, specific and stability method indicating reverse phase high performance liquid chromatography method for simultaneous estimation of teneligliptin and metformin in bulk and tablet dosage form. MATERIALS AND METHODS: The analysis was performed with a Kromasil C18 column (250×4.6 mm, 5 μm) at 30°C using buffer: acetonitrile: methanol (65:25:10, v/v/v) as mobile phase. The detection was carried out with a flow rate of 1.0 mL/min at 254 nm. RESULTS: The retention time of teneligliptin and metformin was 2.842 min and 2.017 min, respectively. The linearity range was 5-30 μg/mL for teneligliptin and 125-750 μg/mL for metformin. The forced degradation studies were performed as per the guidelines of the The International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use under acidic, alkaline, oxidative, thermal, photostability, and neutral conditions. CONCLUSION: This method was successfully validated for all the parameters and could detect the the correct amounts of active drug substance in formulations that are available in the market. This developed method in the present study could be successfully employed for the simultaneous estimation of teneligliptin and metformin in bulk and tablet dosage form.
Synthesis and in vitro studies of thiazolidine-4-carboxylic acid hydrazones as potential antitubercular agents Indian Journal of Chemistry Section B Organic and Medicinal Chemistry, 2018
Comparative in vitro antioxidant activities of ethanolic extract, ethyl acetate extract (EAE), and hexane extracts (HE) of Tecoma gaudichaudi flowers International Journal of Green Pharmacy, 2018
Synthesis, characterization and pharmacological evaluation of some novel 4,5-dihydro pyrazole derivatives bearing thiazole and furan as potent antimicrobial and anticancer agents Research Journal of Pharmaceutical Biological and Chemical Sciences, 2016
Development and validation of stability indicating RP-HPLC method for the simultaneous estimation of levofloxacin and cefodoxime in bulk and their combined dosage form Research Journal of Pharmaceutical Biological and Chemical Sciences, 2015
Design, facile synthesis, characterization and computational evaluation of novel isobutylchalcones as cytotoxic agents: Part-A Fabad Journal of Pharmaceutical Sciences, 2015
Development and validation of RP-HPLC method for the estimation of sitafloxacin in bulk and pharmaceutical dosage forms International Journal of Pharmacy and Pharmaceutical Sciences, 2014
A novel spectrofluorimetric method for the determination of gemifloxacin in bulk and pharmaceutical formulation International Journal of Chemical Sciences, 2014
Synthesis, biological activity and molecular properties prediction of novel chalcones Indian Journal of Heterocyclic Chemistry, 2014
Synthesis, characterization, antibacterial and antifungal activities of Isatin derivatives International Journal of Chemtech Research, 2013
Newer applications of 1,5-benzothiazepines and their cytotoxic and anticonvulsant activity Der Pharmacia Lettre, 2013
Synthesis of novel 1-(4'-fluorophenyl)-3-(4"-aryl)-2-propen-1-ones by conventional and microwave irradiation methods and their pharmacological activities Der Pharmacia Lettre, 2013
Synthesis of 2-[(substituted benzylidene)imino]-3-N-propylcarboxamido-6-N-methyl piperidino thiophenes for in vitro anti-inflammatory and antimicrobial evaluation Der Pharma Chemica, 2013
Synthesis and antimicrobial activity of novel falvonols Der Pharma Chemica, 2013
Synthesis, screening and in vitro anticancer activity of piperazine nucleus containing novel chalcones on different cell lines International Journal of Pharmtech Research, 2013
Development and validation of a reverse phase-HPLC method for the determination of balofloxacin in bulk and pharmaceutical dosage forms Drug Invention Today, 2012
Synthesis of some new thiophenes as anti-inflammatory and antimicrobial agent International Journal of Chemical Sciences, 2012
Estimation of lafutidinen tablet dosage form by RP-HPLC International Journal of Pharmaceutical Research, 2012
Design and Synthesis of 1-(3',5'-bis trifluoromethyl phenyl)-3-(substituted phenyl)-2-propene-1-one as potent antifungal and antibacterial agents Der Pharma Chemica, 2012
Development and validation of novel isocratic RP-HPLC method for the estimation of Prulifloxacin in bulk and pharmaceutical dosage forms International Journal of Pharmaceutical Sciences Review and Research, 2012
Synthesis and biological evaluation of some new 2,4,6-trisubstituted pyrimidines Asian Journal of Chemistry, 2012
Evaluation of the in vivo hypoglycemic effect of neem (Azadirachta indica A. Juss) fruit aqueous extract in normoglycemic rabbits Research Journal of Pharmaceutical Biological and Chemical Sciences, 2012
Dissolution studies and quantification of meloxicam in tablet dosage form by spectrophotometry Pakistan Journal of Pharmaceutical Sciences, 2012
Simultaneous estimation of Metformin HCl and Sitagliptin phosphate in tablet dosage forms by RP-HPLC Research Journal of Pharmacy and Technology, 2011
Simultaneous quantification of efavirenz and lamivudine in tablet dosage form by liquid chromatography Indian Journal of Pharmaceutical Education and Research, 2011
Estimation of Troxipide in tablet dosage form by RP-HPLC International Journal of Pharmacy and Pharmaceutical Sciences, 2011
QSAR studies on bisaryl substituted thiazoles and oxazoles as PPARδ agonists Journal of Chemical and Pharmaceutical Research, 2011
Synthesis and biological evaluation of some novel phenyl thiazole derivatives as possible antimicrobial agents Indian Journal of Pharmaceutical Education and Research, 2011
Development and validation of reversed-phase hplc method for simultaneous estimation of telmisartan and amlodipine in tablet dosage form International Journal of Pharmacy and Pharmaceutical Sciences, 2010
Development and validation of reversed-phase HPLC method for simultaneous estimation of rosuvastatin and fenofibrate in tablet dosage form International Journal of Pharmtech Research, 2010
Development and validation of reversed-phase HPLC method for simultaneous estimation of atorvastatin calcium and telmisartan in tablet dosage form International Journal of Pharmtech Research, 2010
Swine flu- an update Journal of Pharmaceutical Research and Health Care, 2010
Synthesis and pharmacological activities of 5-chloro-3- methylbenzofuran incorporated pyrimidines and isoxazolines Indian Journal of Heterocyclic Chemistry, 2009
Microwave mediated synthesis and antifungal activity of some bicyclic pyrrolidines Indian Journal of Heterocyclic Chemistry, 2009
Synthesis of Some 4′-amino chalcones and their antiinflammatory and antimicrobial activity Asian Journal of Chemistry, 2009
Oral manifestation of AIDS Biosciences Biotechnology Research Asia, 2008
Synthesis and antimicrobial activities of new triazoles Indian Journal of Heterocyclic Chemistry, 2008
Synthesis and antimicrobial activity of 6,7,8,9-tetrahydro-5(H)-5- nitrophenylthiazolo[2,3-b]-quinazoline-3(2H)-one derivatives Asian Journal of Chemistry, 2008
Simultaneous estimation of simvastatin and ezetimibe by PR-HPLC in pure and pharmaceutical dosage form Oriental Journal of Chemistry, 2008
Synthesis and antimicrobial activity of some chalcones of 3-acetyl coumarin and 2-hydroxy-1-acetonapthone Asian Journal of Chemistry, 2007
Synthesis and antidepressant activity of some 3-(3″-coumarinyl)-1,5- diphenyl-2-pyrazolines and 3-(2″-hydroxy naphthalen-1″-yl)-1,5- diphenyl-2-pyrazolines Asian Journal of Chemistry, 2007
Synthesis and antimicrobial activity of some new coumarin derivatives Asian Journal of Chemistry, 2006
Synthesis and antimicrobial activity of some novel chalcones Asian Journal of Chemistry, 2006
