S.R. Dhaneshwar’s research while affiliated with Amity University and other places

A unique, easy, accurate and precise HPTLC method is demonstrated for simultaneously estimating Atenolol, Amlodipine besylate and Aspirin in bulk drug (API) and in capsule dosage forms. The three drugs were separated using precoated aluminum plates, silica gel 60 F254 was used for coating the plates. The mobile phase used for separating the three drugs was n-butanol, water and acetic acid in the ratio of 8: 2: 0.2 v/v/v. The separated bands were evaluated at 235 nm. RF values for the three drugs were 0.23 ± 0.02, 0.47 ± 0.02 and 0.70 ± 0.02 for Atenolol, Amlodipine besylate and Aspirin, respectively. All the three drugs were very well resolved from each other depicting resolution of more than 2. Linearity was performed in the concentration range of 100-600 ng/spot for Atenolol, Amlodipine besylate and Aspirin, and a good linear curve was displayed over the concentration vs area plot. The limit of detection (LOD) was 80 ng/spot and limit of quantitation (LOQ) was 100 ng/spot for Atenolol, Amlodipine besylate and Aspirin, respectively. HPTLC method was successfully applied to capsule dosage form and no interference from excipients was observed. The developed method was validated as per ICH guideline and was found to be specific, precise, robust and accurate. Hence this method can be useful for routine analysis of Atenolol, Amlodipine besylate and Aspirin in pure drug and capsule forms.

Objective: A simple, sensitive, selective, precise repeatable and stability-indicating high-performance thin layer chromatographic method was developed and validated for Eszopiclone in bulk drug and in formulation. Method: Silica gel 60 F-254, TLC precoated aluminium plates was used as the stationary phase for analyzing Eszopiclone and its degradation products, using mobile phase consisting toluene: ethyl acetate: methanol (6: 4: 2 v/v/v). Result: This mobile phase gave compact spots for Eszopiclone with Rf value of 0.52 ± 0.02. Eszopiclone was exposed to hydrolysis, oxidation, neutral and photolytic conditions for conducting stress degradation study. The peak of Eszopiclone and the degradation product was well resolved from each other with a significantly different Rf value. Densitometric estimation of Eszopiclone was performed at 304nm. A good linear plot was obtained in the concentration range of 150-300ng/spot. The method was validated for precision, accuracy (recovery) and robustness study. The limit of detection (LOD) and limit of quantitation (LOQ) was found to be 130ng/spot and 150ng/spot, respectively. Conclusion: The developed HPTLC method can separate Eszopiclone from its degradation products, hence stability studies can be performed using this method.

High performance thin layer chromatography (HPTLC) is becoming increasingly popular amongst analysts for its simplicity of operation and capability of running several samples simultaneously. This coupled with the many stationary phases now available together with the availability of different development techniques makes HPTLC a very powerful separation technique. The introduction of newer spectroscopic detection methods like ultraviolet, infrared, Raman, fluorescence, nuclear magnetic resonance, and the recent combination of HPTLC with Mass Spectrometry (MS) (TLC–MS) has made this method useful for analysts all over the world. That is why HPTLC finds numerous applications in the pharmaceutical field as well. All analyses reported with High Performance Liquid Chromatography (HPLC) are now being performed by HPTLC with a saving of time and cost.

A simple, precise and accurate high performance liquid chromatography (HPLC) method was developed for the simultaneous estimation of mefformin hydrochloride, rosiglitazone maleate, glibenclamide present in multicomponent dosage forms. Chromatography was performed on a 25 cmx4.6 mm id, 5-mu m particle, C-18 column with 78:22 (v/v) methano1:20 mM potassium dihydrogen phosphate buffer as mobile phase at a flow rate of 1.0 ml/min and UV detection at 238 nm for metformin hydrochloride, rosiglitazone maleate and glibenclamide. The total elution time was shorter than 9 min. This method was found to be precise and reproducible. The proposed method was successfully applied for the analysis of mefformin hydrochloride, rosiglitazone maleate, glibenclamide as a bulk drug and in pharmaceutical formulation without any interference from the excipients.

A HPLC method has been described for simultaneous determination of Chlorpheniramine Maleate, Phenylpropanolamine Hydrochloride and Paracetamol in formulation. This method is based on HPLC separation of the three drugs on the Thermo Hypersil Gold C18 column (250mm ×4.6mm, 5.0µ), with isocratic conditions and mobile phase containing methanol: 0.01M disodium hydrogen phosphate dihydrate buffer pH 7 adjusted with Ortho Phosphoric Acid (OPA) (60: 40) at a flow rate of 1mL/min using UV detection at 217 nm. This method has been applied to formulation without interference of excipients of formulation. The linear regression analysis data for the calibration plots showed a good linear relationship over the concentration range of 0.5-3µg/mL for Chlorpheniramine Maleate, 7-12µg/mL for Phenylpropanolamine hydrochloride, and 0.4-1.4µg/mL for Paracetamol, respectively. The mean values of the correlation coefficient, slope and intercept were 0.999 ± 1.72, 28455 ± 1.01, 26185 ± 1.28 for Chlorpheniramine Maleate, 0.999 ± 0.34, 23604 ± 1.16, 73758 ± 1.49 for Phenylpropanolamine hydrochloride and 0.999 ± 0.80, 51233 ± 1.89, 5560 ± 1.62 for Paracetamol respectively. The method was validated for precision, robustness and recovery. The limit of detection (LOD) and limit of quantitation (LOQ) was 0.5μg/mL and 1μg/mL for Chlorpheniramine Maleate, 5μg/mL and 7μg/mL for Phenylpropanolamine hydrochloride and 0.2µg/mL and 0.4µg/mL for Paracetamol, respectively. Statistical analysis showed that the method is repeatable and selective for the estimation of, Chlorpheniramine Maleate, Phenylpropanolamine hydrochloride and Paracetamol.

Aim: To develop and validated stability-indicating RP-HPLC-PDA assay method for quantitative determination of dexketoprofen and thiocolchicoside in bulk drugs and in pharmaceutical dosage form. Method: Methanol: water (60:40% v/v) was used as mobile phase at the flow rate of 0.7ml/min using a Kromasil C18 column (250mm×4.6mm, 5.0μ particle size), column was maintained at 35°C. The detection was carried out at the wavelength of 254nm and injection volume was 10μl. The peak purity was checked with the PDA detector. Result: The developed method was validated with respect to linearity, accuracy (recovery), precision, specificity and robustness. Linearity range was found to be 3.125-125μg/ml results for all the parameters were within the limit. Conclusion: The method is very simple, rapid and economic in nature as all peaks are well separated, which makes it especially suitable for routine quality control analysis work. © 2013 JPR Solutions. Published by Reed Elsevier India Pvt. Ltd.

A simple, precise and accurate HPLC method was developed for estimation of Doxofylline (DO) and Terbutaline Sulphate (TS) in formulation. HPLC separation was achieved with Thermo Hypersil BDS-C18 (250 mm × 4.6 mm, 5.0 μ) with isocratic conditions and simple mobile phase containing methanol: Aq. phosphate buffer (pH- 4.55) (90:10 v/v) at flow rate of 1 mL/min using UV detection at 282nm. The retention time of DO and TS were found to 2.925 and 4.233 min respectively. The developed method was validated as per ICH guidelines.

Pramipexole belongs to a class of nonergot dopamine agonist recently approved for the treatment of early and advanced Parkinson's disease. A validated specific stability indicating reversed-phase liquid chromatographic method has been developed for the quantitative determination of pramipexole in bulk as well as in pharmaceutical dosage forms in the presence of degradation products. Forced degradation studies were performed by exposition of drug to hydrolytic (acidic and basic), oxidative and photolytic stress conditions, as defined under ICH guideline Q1A (R2). Significant degradation was observed under hydrolytic, oxidative and photolytic conditions and the degradation products formed were identified by LC–MS.

A simple, sensitive and rapid reverse phase high performance liquid chromatographic method was developed for the estimation of Benfotiamine (BEN) and Metformin Hydrochloride (MET) in pure and in pharmaceutical dosage forms. Thermo Hypersil BDS-C18 Column (250 mm × 4.6 mm, 5.0 μ Germany) with isocratic conditions was used with a mobile phase containing mixture of Methanol and Aq. Phosphate buffer (10mM of Potassium Dihydrogen Phosphate adjusted to 3.2 with ortho phosphoric acid) in the ratio of 80: 20. The flow rate was 1 ml/min and effluents were monitored at 239nm and eluted at 2.583 min (BEN) and 3.233 min (MET). Calibration curve was plotted with a range of 1-6 μg/ml for BEN and 0.1-5 μg/ml for MET. The assay was validated for the parameters like accuracy, precision, robustness and system suitability parameters. The proposed method can be useful in the routine analysis for the determination of Benfotiamine and Metformin Hydrochloride in pharmaceutical dosage forms.