Jinesh Bahubali Nagavi

A simple, sensitive, accurate and specific stability-indicating high-performance liquid chromatographic method was developed and validated for the estimation of clopidogrel bisulphate in bulk. In the present study, extensive testing of clopidogrel bisulphate in different stress conditions were carried out as per the ICH guidelines Q1A (R2). The system consisted of a pump (Shimadzu, prominence, LC20AD), with 20µl sample injector, along with a PDA (Shimadzu, prominence, SPDM20A) detector at a wavelength of 254nm. Data was compiled using Shimadzu LC Solution software. The degraded products formed under various stress conditions were separated successfully from the drug by using a PHENOMENEX C8 Column (150 x 4.6mm, 5µm) with binary gradient conditions. Acetonitrile: phosphate buffer of pH 2.0 was used as mobile phase at flow rate of 1.2ml/min. Clopidogrel bisulphate was exposed to various stress conditions like oxidation, hydrolysis, photolysis and neutral decomposition. Clopidogrel bisulphate, which was found to degrade considerably in acidic, photo and oxidative conditions, was found to be stable in alkaline and neutral conditions. Apart from the formation of minor degraded products under accelerated conditions, the drug was reasonably stable in solid state. A good linear relationship over the concentration range of 150-500µg/ml was shown. Validation of the method was carried out as per the ICH guidelines. The method developed was found to be precise, accurate, specific and selective. Clopidogrel bisulphate showed degradation in 5M Hydrochloric acid at 80oC, in 3% hydrogen peroxide for 5min the drug showed around 35% of degradation, when exposed to sunlight for 15 min, formed around 25-30% of degradation products. Statistical analysis shows that the method is reproducible and selective for the estimation of clopidogrel bisulphate in dosage form.

A HPLC method for simultaneous estimation of Ramipril and Hydrochlorothiazide in tablets was developed and validated. The developed method involves Purosphere® Star Rp18e, 5μm, 150×4.6mm column with mobile phase composition of acetonitrile and sodium perchlorate (pH 2.5) buffer in the ratio of 3:2, at a flow rate of 1.0 ml/min and UV detection at 316nm for first five minutes for Hydrochlorothiazide and 210nm for Ramipril. The method was validated as per ICH guidelines, Linearity was observed over concentration range of 17.5 to 32.5 µg/ml for Ramipril and 87.5 to 162.5 µg/ml for Hydrochlorothiazide. The Accuracy of the proposed method was determined by recovery studies and found to be 97.95-102.3% and 97.98-102.66% for Ramipril and Hydrochlorothiazide respectively. The proposed method was extended for estimation of Ramipril and Hydrochlorothiazide in marketed tablet formulation (Ramace-HTM) and it was found to be well within the acceptance limit. The developed and validated HPLC method for simultaneous estimation of Ramipril and Hydrochlorothiazide was found to be linear, accurate, precise, robust and rugged. Hence it can be used for routine analysis of Ramipril and Hydrochlorothiazide in tablets.