Telmisartan

ABSTRACTA simple, accurate, precise, and cost-effective reversed-phase high-performance liquid chromatography (RP-HPLC) method has been developed and validated for the simultaneous estimation of Telmisartan and Cilnidipine in bulk and marketed tablet dosage form. Chromatographic separation was achieved using an Agilent C18 column (250mm × 4.6mm, 5 ?m) with a mobile phase consisting of Acetonitrile and phosphate buffer (pH 3.0) in a 90:10 v/v ratio, at a flow rate of 1.0 mL/min and detection wavelength of 254 nm. Method validation followed ICH Q2 (R1) guidelines for system suitability, linearity, accuracy, precision, robustness, LOD, and LOQ. The method showed linearity over the range of 40–240 ?g/mL for Telmisartan and 10–60 ?g/mL for Cilnidipine, with correlation coefficients (R²) of 0.9998 for both drugs. The method was found to be accurate, precise (%RSD < 2%), robust, and suitable for routine quality control analysis in pharmaceutical formulations. Keywords: Telmisartan, Cilnidipine, RP-HPLC, Method Validation, ICH Q2(R1), Fixed-Dose Combination

The simple, sensitive, reliable and economically new method was developed for the estimation of Ramipril (RAM) and Telmisartan (TEL) by RP-HPLC in combined dosage form. After several trials with the different combinations and ratios of solvents, the present chromatographic parameters were optimized. It was found that potassium dihydrogenphosphate (pH 3.0): methanol: acetonitrile (30:20:50 v/v/v) was given satisfactory results. A C18 column (Agilent ODS UG 5 column) having dimensions of 4.5mmx250mm was used. The mobile phase was pumped at a flow rate of 1.0ml/min and the eluents were monitored at 210nm. System suitability was carried out by injecting six replicate injections of 100% standard concentration, number of theoretical plates, HETP(height equivalent Theoretical plate) and resolution were satisfactory. The optimized chromatograms confirm the presence of Ramipril and Telmisartan at Rt: 4.1 min and Rt: 5.11min respectively without any interference. The concentration range of 1-5µg/ml for RAM and 8-40µg/ml for TEL were linear with correlation coefficients 0.999 and 0.989 respectively. The percent recovery studies were found to be 99.5-99.88% and 99.93-99.99% w/w for RAM and TEL respectively which indicate method was accurate. The proposed method was precise and reproducible with %RSD of 0.93 for Ramipril and 0.41 for Telmisartan, respectively. The limits of detection and limits of quantification were 0.10µg/ml and 0.25µg/ml for Ramipril 0.32µg/ml and 0.78µg/ml for Telmisartan, respectively. The method was found to be robust and ruggedness and was well suitable for the estimation of commercial formulations of selected combinations.

A simple, accurate, precise and fast reverse phase, gradient RP-HPLC method was developed for the separation of telmisartan and hydrochlorothiazide in combination dosage form of Tablets. The method was carried out by using Kromasil, C18, 4.6 x 150mm, 5 μm enhanced polar selectivity column and mobile phase comprised of potassium dihydrogen phosphate buffer pH adjusted to 3.2 ± 0.5 with orthophosphoric acid and acetonitrile, and degassed under ultrasonication. The flow rate was 1.5 mL/min and the effluent was monitored at 225nm. The retention time of hydrochlorothiazide and telmisartan were 2.7 ± 0.5 and 7.3 ± 0.5 respectively. The method was validated as per ICH guideline. The proposed method is suitable for simultaneous determination of telmisartan and hydrochlorothiazide in pharmaceutical dosage form.