In vitro studies The dissolution test were carried out using a USP type I apparatus (model TDT-08l, Electrolab, Mumbai, India) at 100 rpm and 37°C for the first 2 h in simulated gastric condition (0.1NHCl) and later in 900 mL of pH 7.4 phosphate buffer. Five ml of the dissolution samples was withdrawn at regular intervals of time and replaced with an equal volume of drug-free dissolution fluid to maintain sink conditions. The samples were suitably diluted with blank dissolution fluid and analyzed for drug release by UV-visible spectrophotometer at 237 nm [5].