Preparation and in vitro/in vivo evaluation of felodipine nanosuspension

The purpose of this study was to develop a nanosuspension of a poorly soluble drug felodipine by nanoprecipitation to achieve superior in vitro dissolution and high oral absorption in vivo in rats. Felodipine nanosuspensions were prepared by precipitation with ultrasonication method using polyvinyl alcohol (PVA) and hydroxy propyl methyl cellulose (HPMC) as stabilizers. The particle size of nanosuspension with PVA was 60-200 nm, while with HPMC is 300-410 nm. The in vitro dissolution and pharmacokinetics of optimized nanosuspensions were studied after oral administration in male wistar rats. The results showed significant improvement during in vitro dissolution and in vivo plasma level. Dissolution studies of lyophillised nanoparticles showed that up to 93.0 % dissolved in 2 h. In the in vivo evaluation, nanosuspension exhibited significant increase in AUC(0-24), C (max) and decrease in t (max). The findings revealed that particle size reduction can influence felodipine absorption in gastrointestinal tract and nanosuspension can enhance oral bioavailability of felodipine in rats.