Synthesis and Characterization of calcium Starch: A New Controlled Release Polymer for floating tablets of Losartan Potassium

Losartan potassium is used to treat high blood pressure (hypertension). The present study was aimed to prepare a floating drug delivery system to design a controlled release oral dosage form of Losartan potassium. This helps to overcome the demerit of limited residence time of the drug in the gastrointestinal track and hence to increase the duration of release. Hence objective of the present study is to develop Losartan potassium floating tablets by direct compression method using calcium starch as release retarding polymer. The calcium starch was synthesized by gelatinizing potato starch in the presence of sodium hydroxide and cross linking by treatment with calcium chloride. The micromeritic properties studies indicated that calcium starch is a promising pharmaceutical excipient in tablets. Floating tablets of Losartan potassium was formulated by direct compression technique, using different concentration of calcium starch and compared with HPMC K-100 as release retard polymer. As the amount of calcium starch in the tablet increased, the drug release decreased. The formulation F5 containing 125 mg calcium starch showed better controlled release of 76.38% after 12 hours.