Objective of the present study was to develop hydrophilic polymer and hydrophobic polymer based matrix Losartan potassium sustained release tablet which can release the drug up to time of 24 hrs in predetermined rate. Formulation of Losartan potassium matrix tablet was prepared by the polymer combination in order to get required theoretical release profile. Influence of hydrophilic and hydrophobic polymer on Losartan potassium was studied. Formulated tablet were also characterized by physical and chemical parameters. In vitro release profile was check for 24 hrs to evaluate the SR matrix tablet of Losartan potassium. Losartan potassium (LP) is a potent, highly specific Angiotensin II type 1 (AT1) receptor antagonist with antihypertensive activity. It is readily absorbed from the gastrointestinal tract with oral bioavailability of about 33% and a plasma elimination half-life ranging from 1.5 to 2.5 hr. Administration of LP in a sustained release dosage would be more desirable for antihypertensive effects by maintaining the plasma concentrations of the drug well above the therapeutic concentration. From in vitro dissolution profile, Batch B4 was prepared with blend of HPMC K4M (67.2 mg), HPMC K200M(90mg) and Eudragit RSPO(112.5 mg), where drug release was about 94-98%. Batch B4 showed highest similarity factor values (f2 = 67.76).

Toxicology, the study of poisons, focuses on substances and treatments that cause adverse effects in living things. A critical part of this study is the characterization of the adverse effects at the level of the organism, the tissue, the cell, and the molecular makeup of the cell. Thus, Toxicology traditionally has focused on phenotypic changes in an organism that result from exposure to chemical, physical, or biologic agents. Such changes range from reversible effects, such as transient skin reactions, to chronic diseases, such as cancer, to the extreme end point of death. Typical whole-animal toxicology studies may range from single-dose acute to chronic lifetime exposures, and they include assessments of end points such as clinical signs of toxicity, body and organ weight changes, clinical chemistry, and histopathologic responses.