Method validation.

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.

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.

A specific and accurate HPLC method is developed for the determination of etoposidein bulk drugs and in solid capsule dosage form. Best symmetric peak shape obtained with Inertsil ODS C-18 column (250 X 4.6 mm, 5μ) column in an isocratic mode, with retention time 5 min.The mobile phase used was Water : Acetonitrile  60:40(v/v)with flow rate 1.0 ml/min and effluent was monitored at 263 nm. As per ICH guidelines method has validated. Method has found linear in the range of 5-45 µg/ml. The LOD and LOQ were found to be 0.02 and 0.06 µg/ml respectively. Method was found specific with respective of diluents, excipients and degradants.

This research manuscript describes simple, sensitive, accurate, precise and repeatable reverse phase high performance liquid chromatography method for the estimation of Ketoconazole in tablet dosage form. The sample was analyzed by reverse phase ACE 5 C18 column (150 mm × 4.6 mm i.d, 5 μm particle size) as stationary phase; methanol: acidic water  [91:9, v/v] pH 3.0 as a mobile phase at a flow rate of 0.85 ml/min. Quantification was achieved with Photo Diode Array detector at 243 nm. The retention time for Ketoconazole was found to be 2.764 min. The linearity was obtained in the concentration range of 5-40 µg/ml for Ketoconazole. The method was successfully applied to tablet because no chromatographic interferences from formulation excipients were found. The method retained its accuracy and precision when the standard addition technique was applied.

This research manuscript describes simple, sensitive, accurate, precise and repeatable reverse phase high performance liquid chromatography method for the estimation of Chlorhexidine gluconate in mouthwash. The sample was analyzed by reverse phase ACE 5 C18 column (150 mm × 4.6 mm i.d, 5 μm particle size) as stationary phase; acetonitrile : methanol : triethyl Amine (0.1 %) PH 3.0 (22: 49: 29, v/v/v) as a mobile phase at a flow rate of 0.8 ml/min. Quantification was achieved with Photo Diode Array detector at 258 nm. The retention time for chlorhexidine gluconate was found to be 2.477 min. The linearity was obtained in the concentration range of 10 -80 µg/ml for chlorhexidine gluconate. The method was successfully applied to mouthwash because no chromatographic interferences from formulation excipients were found. The method retained its accuracy and precision when the standard addition technique was applied.

A simple, accurate, precise, specific, sensitive, reproducible and Reliable RP- HPLC Method was developed for Quantitative Estimation of Metaxalone and Diclofenac potassium in Pharmaceutical Dosage Form. The developed RP- HPLC method with the mobile phase Methanol: Water (80: 20) and Qualisilgold-C18 (250Χ4.6mm, 5μm particle size) as stationary phase with a flow rate of 1.0 mL/minute by using λmax 275nm and PDA detector. Proposed method was found to be linear in the concentration range of 8.0 to 80.0 μg/mL for Metaxalone and 1.0 to 10.0 μg/mL for Diclofenac potassium respectively, and the correlation coefficient was found to be 0.9991 for both the drugs. Precision study showed that the % RSD was within the range of acceptable limits (< 2), and the % Recovery was found to be in the range of 99.29%-101.28% for Metaxalone and 99.98%-102.45% for Diclofenac potassium. The proposed method has been validated as per ICH guidelines.