Development, in-vitro and in-vivo characterization of gelatin nanoparticles for delivery of an anti-inflammatory drug

The present investigation involves the preparation of gelatin nanoparticles laden with naproxen, an anti-inflammatory drug. The nanoparticulate formulations were prepared by a modified two step desolvation technique upon varying the crosslinking ratio with drug and polymer and were assessed for their analgesic and anti-inflammatory activities. Particles of nanometer size range were formulated (177 ± 2.17-142 ± 2.06 nm) and the size distribution was monodisperse in the entire prepared batches with low polydispersity index. Entrapment efficiency of the nanoformulations was from 65 to 42%. DSC thermograms reported molecular level dispersion of drug in the nanoparticles whilst FTIR studies exhibited no drug-polymer interaction. Batches (NGP1-NGP8) exhibited an initial burst release followed by controlled release of the drug, the Korsmeyer-Peppas showed better linearity and the formulations displayed non-Fickian drug release pattern. Investigations were executed to analyze the analgesic and anti-inflammatory effects of the optimized formulation. The drug loaded nanoparticles exhibited significant (P<0.05) analgesic activity (acetic acid induced abdominal constriction & tail flick test in mice) and anti-inflammatory activity (carrageenan induced rat paw edema) in comparison to marketed product.