Losartan potassium is an antihypertensive agent used in the treatment of hypertension which has low peak plasma concentration and half-life. It has been selected as candidate for the formulation of sustained release dosage forms. In the present work losartan potassium loaded chitosan nanoparticles were prepared by ionic gelation of chitosan with tripolyphosphate anions. Nanoparticles of different core: coat ratio were formulated and evaluated for drug content, loading efficiency, particles size, zeta potential, In vitro drug release and stability studies. Scanning Electron Microscopy indicated that the nanoparticles were found to be in nanometer range and showed ideal surface morphology. Differ ential scanning calorimetry analysis indicated that there were no chemical interactions between drug and polymer and stability of drug. In vitro release behavior from all the drug loaded batches were found to follow zero order and provided sustained release over a period of 24 hours. No appreciable difference was observed in the extent of degradation of product during 60 days in which nanoparticles were stored at various temperatures. The developed formulation overcomes and could possibility be advantageous in terms of sustained release dosage forms of losartan potassium.
Key words: Nanoparticles, Chitosan, Losartan potassium, Ionic gelation technique.
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