Preparation and evaluation of nanosuspension of nifedipine

Processing a poorly soluble drug is a challenging task during formulation development. Nano suspension is one of the techniques that can improve the dissolution of poorly soluble drug. Nanosuspension is the fine dispersion of uniform-sized solid particles in an aqueous vehicle. The present work was aimed at the formulation and evaluation of nanosuspension of Nifedipine, a poorly water soluble anti-hypertensive drug. The nanosuspensions were prepared by nanoprecipitation alone and in combination with ultrasonication method using acetone as solvent and water as antisolvent. The prepared nanosuspensions were characterized for particle size, zeta potential, polydispersity index, Scanning electron microscopy (SEM), drug entrapment efficiency and release behaviour. The effect of variable concentration of drug, stabilizer, extent of ultrasonication, and solvent to antisolvent ratio on the physical, morphological and dissolution properties of Nifedipine were studied. The average particle size of Nifedipine nanoparticles was found to be in the range of 13–230 nm. It was further confirmed by SEM photograph. The particle size varies with increase in concentration of drug and stabilizer. The preparations showed negative zeta potential and polydispersity index in the range of 0.3-0.9. The dissolution of prepared Nifedipine nanoparticles markedly increased as compared to the pure drug. The dissolution profiles of nanosuspension formulation showed up to 74.4 % release in 4 h. It may be concluded that the nanoprecipitation with ultrasonication have potential to formulate homogenous nanosuspensions with uniform-sized stable nanoparticles of Nifedipine. The prepared nanosuspension showed enhanced dissolution which may lead to enhanced oral bioavailability of Nifedipine.