Studies On Valsartan-Loaded Solid Lipid Nanoparticles

Valsartan is an oral effective non-peptide angiotensin receptor Ⅱ anticaking agent. It is suitable for various kinds of mild-to-modreate hypertension. Because of the low bioavailability, its clinical application is greatly limits.Valsartan solid lipid nanoparticles were prepared by emulsification evaporation-solidification at low temperature with glycerin monostearate and the orthogonal design was applied to optimize its formula and technology. The morphology,particle size,entrapment efficiency and stability were investigated. In result, the valsartan solid lipid nanoparticles were sphere-like with a mean diameter of (362.7±8.75)nm. The entrapment efficiency and drug-loading rate were (63.89±0.36)%and (1.07±0.016)%.There were no obvious changes in entrapment efficiency and drug-loading rate when loaded drug at4℃within a month. The results of released in vitro showed tally with the first order dynamic model.An HPLC method was developed for the determination of Valsartan solid lipid nanoparticles in mice plasma. Oral pharmacokinetic behaviors of VST suspension and VST-SLN were investigated in rats. The results showed that oral absorption has a markly improvement in Valsartan solid lipid nanoparticles. The AUC0-t are1843.43ng/ml-h and2052.97ng/ml-h; The Cmax are563.81ng/ml and813.95ng/ml. Cmax rose by144%and AUC0-t rose by109%,so no significant increase in bioavailability.