DEVELOPMENT OF UV SPECTROSCOPY AND HPTLC METHOD FOR THE ANALYSIS OF DOFETILIDE AND ITS DEGRADATION PRODUCTS

Rapilane Krishnamurthi Sangeetha*, Thengungal Kochupapy Ravi and Muruganathan Gandhimathi

ABSTRACT

There are no reported methods till date for the analysis of dofetilide by UV spectroscopy and HPTLC method as a single drug. The aim of the present study is to develop a UV spectroscopic and HPTLC method and validate it according to ICH guidelines. The developed method was adopted for the stability testing of dofetilide. The maximum absorbance in UV spectroscopy was found at 231 nm with methanol as the solvent. The linearity was established at the concentration range of 2-18 mcg/ml with a correlation coefficient of 0.9987 .The Interday and intraday studies gave reproducible values with a % RSD of less than 1.The HPTLC method was developed with a mobile phase of Methanol: Toluene: Acetonitrile in ratio of 4:2:4. The Rf value was found to be 0.60 ± 0.02 with symmetrical peaks. The linearity range was 1000-10000 ng/spot with a correlation coefficient of 0.9961. The precision studies were found to be acceptable and % RSD value was found to be below 1. The drug was subjected to various stress conditions of acid hydrolysis, base hydrolysis, oxidation, photolysis and thermal degradation according to ICH guidelines. Successful separation of the drug peak and the degradants were found at well separated Rf value. The drug was found to be stable with acid hydrolysis, oxidation, base hydrolysis and thermal degradation at 40oC upto 4 hours with degradation of less than 10% and the degradation of more than 10% was found in elevated temperature of 40oC after 4 hours, 60oC, 80oC and photolysis. The drug solution was found to be stable at room temperature for 44 hours and in refrigeration for 7 days. The method developed has the merit of being simple, economical, sensitive and accurate for the analysis of dofetilide in bulk drugs.

Keywords: Dofetilide, UV Spectroscopy, HPTLC, Degradation studies, Stability Indicating method.