Validated UV and Rp-Hplc Methods for the Simultaneous Estimation of Amlodipine Besylate and Indapamide in Bulk and Tablet Dosage form.

The present study is the prime importance of drug analysis is to gain information about the qualitative and quantitative compositions of substance and chemical species, that is to find out what a substance is composed of and exactly how much. This information guides development of the manufacturing operations and therapeutic action of drugs. Standard analytical procedure for newer drugs or its formulation may not be available in Pharmacopoeias. Hence it is essential to develop newer analytical methods which are accurate, precise, specific, linear, simple and rapid. Amlodipine besylate and Indapamide is a newer combination which is yet to be launched in Indian market. Hence, the present study aims to develop simple, precise and accurate methods for the determination of Amlodipine besylate and Indapamide by simple UV methods and RP-HPLC method. The combination dosage form selected for the present study contains Amlodipine besylate and Indapamide in solid oral dosage forms, recently this combination of the drugs are introduced into the market. Simple, rapid, precise and accurate UV Spectrophotometric method and RPHPLC method were developed and validated for the estimation of Amlodipine besylate and Indapamide in tablet dosage form. UV SPECTROSCOPIC METHODS: From the solubility profile and stability studies, methanol followed by Borate buffer pH 8.0 was chosen as a common solvent for the estimation of Amlodipine besylate and Indapamide. The sample solutions of 10 μg/ml of Amlodipine besylate and Indapamide in methanol followed by Borate buffer - pH 8.0 prepared individually and the solutions were scanned in the wavelength range from 200 to 400 nm by using methanol and 0.2M Borate buffer - pH 8.0 as blank. The overlaid spectra of mixture of Amlodipine besylate and Indapamide were recorded. From the spectra, 339.0 nm for Amlodipine besylate and 293.0 nm for Indapamide were selected as wavelength. The same spectrums were derivatised and 339.0 nm selected for detection of Amlodipine besylate where Indapamide shows zero crossing and also 293.0 nm selected for detection Indapamide where Amlodipine besylate shows zero crossing. The percentage label claim present in the formulation was found to be 98.60 ± 0.6196 and 99.325 ± 1.2554 for Amlodipine besylate and Indapamide respectively. The percentage recovery was found to be in the range of 98.03- 99.67% for Amlodipine besylate, and 98.30 – 101.10% for Indapamide. RP – HPLC METHOD: In RP-HPLC method, mobile phase used is Acetonitrile: Methanol: 0.04M Phosphate buffer - pH 3.0 (25:30:45 v/v/v) with flow rate of 1.0 mL per min, the retention time of Amlodipine besylate and Indapamide were found to be 8.77 and 6.62, respectively at 240.0 nm. The percentage purity was found to be 100.86 ± 0.7023 and 100.61± 0.4471 for Amlodipine besylate and Indapamide, respectively. The precision of the method was confirmed by repeatability of formulation for six times. The accuracy of the method was confirmed by recovery studies. The percentage recovery was found to be in the range between 100.06 and 101.65 % for Amlodipine besylate and 100.4 and 101.39% for Amlodipine besylate and Indapamide. The low % RSD values for recovery indicated that the method was found to be accurate. Simple, rapid and accurate UV Spectroscopic (First order derivative method) and an isocratic RP – HPLC methods showed excellent sensitivity