Forced degradation

To develop a simple, precise, accurate, and stability indicating a UV-method for estimation of Clotrimazole. In bulk and formulated dosage form. The method was under subjected to stress degradation at different conditions recommended by the International Conference on Harmonization (ICH). The drug samples are generated and used for the degradation studies. The λmax of the Clotrimazole was found to be 220 nm. The linearity of calibration curve (Absorbance Vs Concentration) in pure solution was checked over the concentration ranges of about 5-30μg/ml for Clotrimazole respectively, with the correlation coefficient higher than 0.999. The regression equation of the curve was Y = 0.0168x + 0.0041. The % RSD was found to be within the limit as per ICH guidelines. The obtained percentage recovery of Clotrimazole was found to be within the limit 100% ± SD. The proposed method can be successfully applied for the method development, validation and stress degradation studies of Clotrimazole. The percentage degradation limit should be 5-20%. The drug Clotrimazole was found to be within the limit.

A new simple, accurate, precise and selective stability indicating high performance thin layer chromatographic method has been developed and validated for estimation of Orlistat Tablet.T he mobile phase selected was Toluene: Methanol(8:2v/v) with UV detection at 211nm.The retention factor for Orlistat was found to be 0.60±0.02. The method was validated with respect to linearity, accuracy, precision and robustness as per the ICH guidelines. The drug were subjected to stress condition of hydrolysis (acid, base), oxidation, photolysis and thermal degradation. Results found to be linear in concentration range of 6000-36000 ng/band. The thermal method has been successfully applied for the analysis of drug in pharmaceutical formulation. The % assay (Mean ± S.D) was found to be 99.30±1.10.The developed method can be used for checking the stability of  Orlistst in bulk drug and pharmaceutical dosage form.

A rapid and sensitive stability indicating RP-HPLC method was developed for simultaneous estimation of salbutamol, carbocisteine and theophylline in combined tablet formulations. Chromatography was carried out on a Discovery HS C18 HPLC Column at 35 °C (250 x 4.6 mm; 5m) by eluting with a mobile phase consisting of a 50:50 v/v mixture of acetonitrile and 0.1 % orthophosphoric acid in water at a flow rate of 1.0 mL/ min. The detection wavelength was set at 215 nm. Accuracy was assessed by using standard addition method. The developed HPLC method was validated with respect to precision, specificity, accuracy, linearity and robustness. Forced degradation studies on the formulation were conducted by adopting the proposed method to assess the stability of the analytes under acid, base, peroxide, thermal and photolytic conditions and suitability of the method to resolve the degradation products.

To develop rapid, rugged, precise and an accurate stability indicating analytical method for estimation of related substances in Ursodeoxycholic Acid tablets. The separation of impurities and Ursodeoxycholic Acid drug is achieved by an isocratic chromatographic method on C18, 250 mm x 4.6 mm, 5µm column. The mobile phase consists of buffer, acetonitrile and methanol in the ratio of 35:28:37 v/v/v pumped at a flow rate of 1.0 ml/minute 35:37:28v/v/v pumped at a flow rate of 1.0 ml/minute. The detection was carried out by using refractive index (RI) detector. The proposed chromatographic method was validated and found to be linear over the concentration range from LOQ to 150.0% of impurity limit level.  Overall mean recovery of Chenodeoxycholic acid impurity was found to be 100.6±4.0%w/w The method was found to be simple, stability indicating, precise, accurate and robust which can be utilized for estimation of related substances in Ursodeoxycholic Acid tablets

Fluindione is an oral anticoagulant drug. A simple and rapid and was validated stability indicating HPLC method for Fluindione was successfully developed and was validated. This method is based on HPLC separation followed by UV detection at 285 nm. HPLC method was developed on a Symmetry thermo C18 (4.6 x 250 mm) column with a mobile phase consisting of 10mM di-sodium hydrogen phosphate buffer pH 3.5: methanol 15:85 v/v, pumped at 1.0 ml min-1 flow rate. The pH of buffer was adjusted to 3.5 with ortho phosphoric acid. The column was maintained at ambient temperature and 20μl of solutions were injected. The eluted compound was detected by using PDA detector. Fluindione was eluted at 2.4 ± 0.2 min. Stress degradation study shows that sample degraded with acid and base hydrolysis, under oxidation, thermal and photolytic stress conditions. The method was validated in accordance with requirement of ICH guidelines.

A simple, sensitive and reproducible stability indicating RP-HPLC method for the simultaneous determination of Phenylephrine and Ebastinein bulk and Pharmaceutical dosage formhas been developed and validated. Chromatographic separation was carried out on kromasil C18 (250×4.6mm, 5mparticle size) column using a mobile phase composed of Phosphate buffer (adjusted to pH 5.0 with dilute OPA): acetonitrile: methanol in the ratio of 30:45:25 %v/v/vat a flow rate of 0.8 ml/min. The analyte was monitored using PDA detector wavelength at 211 nm. The retention time was found to be 2.295 min and 4.225 min for Phenylephrine and Ebastine respectively. The proposed method was found to be having linearity in the concentration range of 25-150µg/ml for both Phenylephrine(r20.99996)and Ebastine(r20.99987)respectively. The developed method has been statistically validated according to ICH guidelines. Stress testing which covered acid, alkali, peroxide, photolytic and thermal degradation was performed on under test to prove the specificity of the method and the degradation was achieved. The proposed method can be successfully applied for the stability indicating RP-HPLC simultaneous determination of Phenylephrine and Ebastine in bulk and combined tablet dosage form and in routine quality control analysis.

A simple and precise stability indicating RP-HPLC method was developed and validated for the simultaneous determination of Hydrochlorothiazide (HCTZ) and Nebivolol Hydrochloride (NBV) inbulk and Pharmaceutical dosage forms. Chromatography was carried out on Thermo Hypersil BDS C 18 (150 x 4.6 mm, 5mparticle size) column using a mobile phase of phosphate buffer (adjusted to pH 6.5 with dilute orthophosphoric acid): acetonitrile (40:60% v/v) at a flow rate of 0.8 ml/min. The analyte was monitored using PDA detector at 282 nm. The retention time was found to be2.4 min and 4.0min for Hydrochlorothiazide and Nebivolol Hydrochloride respectively. The proposed method was found to be having linearity in the concentration range of 6.25-37.5 µg/ml for Hydrochlorothiazide (r2 0.9999) and 2.5-15 µg/ml for Nebivolol Hydrochloride (r2 0.9999) respectively. The mean % recoveries obtained were found to be 99.93 % for Hydrochlorothiazide and 100.03% for Nebivolol Hydrochloride respectively. Stress testing which covered acid, alkali, peroxide, photolytic and thermal degradation was performed on under test to prove the specificity of the method and the degradation was achieved. The developed method has been statistically validated according to ICH guide lines and found to be simple, precise and accurate with the prescribed values. Thus the proposed method was successfully applied for the stability indicating simultaneous determination of Hydrochlorothiazide and Nebivolol Hydrochloridein bulk and Pharmaceutical formulations and in routine quality control analysis.

The objective of the present research work is to develop a isocratic reversed-phase liquid chromatographic (RP-HPLC) method for the determination of Aspirin in pharmaceutical pharmaceutical dosage forms for its related impurities in presence of esomeprazole. The chromatographic separation was achieved on a RP 18 column (100mm×4.6mm, 5 µm). The isocratic LC method employs mixture of buffer methanol and isopropyl alcohol in the ratio of (84:13:3 v/v) solutions as mobile phase. The buffer solution contains 6.8g of Potassium dihydrogen orthophosphate adjusted to pH 2.5 with orthophosphoric acid .The flow rate was 1.5 ml/min and the detection wavelength was 275 nm. In the developed HPLC method, the resolution between Aspirin and its potential impurity salicylic acid was found to be greater than 4.0. The drug was subjected to stress conditions of hydrolysis, oxidation, photolysis and thermal degradation in presence of esomeprazole. Considerable degradation was found to occur in basic medium and mild degradation observed in acid hydrolysis stress conditions. Degradation product formed during acidic hydrolysis was salicylic acid. The stress samples were assayed against a qualified reference standard and the mass balance was found close to 99.5%. The developed RP-HPLC method was validated with respect to linearity, accuracy, precision and robustness.

The objective of the present research work is to develop a gradient, reversed-phase liquid chromatographic (RP-UPLC) method for the determination of Dutasteride in pharmaceutical bulk drugs for assay and its related impurities. The chromatographic separation was achieved on a Waters ACQUITY TM UPLC C8 Column (100mm×2.1mm, 1.7µm),. The isocratic LC method employs mixture of buffer and Acetonitrile in the ratio of (50:50 v/v) solutions as mobile phase. The buffer solution contains 1.0mM potassium di hydrogen orthophosphate pH adjusted to 5.0 with dil.Potassium hydroxide solution (Buffer) .The flow rate was 0.4 ml/min and the detection wavelength was 210 nm. In the developed UPLC method, the resolution between Dutasteride and its potential impurities, namely Imp-1, Imp-2 and Imp-3 was found to be greater than 4.0. The drug was subjected to stress conditions of hydrolysis, oxidation, photolysis and thermal degradation. Considerable degradation was found to occur in Acidic medium and mild degradation observed in base hydrolysis stress conditions. Degradation product formed during acidic hydrolysis was found to be Unknown impurity. The stress samples were assayed against a qualified reference standard and the mass balance was found close to 99.5%. The developed RP-UPLC method was validated with respect to linearity, accuracy, precision and robustness. The developed method was found to be linear in the range of 2.5-15µg/mL with correlation coefficient of 0.999 for assay procedures and found to be linear in the range of 0.05-3µg/mL with correlation coefficient of 0.999 for related impurities