Improvement of nanoprecipitation technique for preparation of gelatin nanoparticles and potential macromolecular drug loading.

An optimum nanoprecipitation technique for gelatin nanoparticles is established, based on aqueous gelatin solution and ethanolic solution containing stabilizer. Crosslinking with glutaraldehyde results in stable gelatine nanoparticles. Several factors such as the surfactant concentration, type of surfactant, type of nonsolvent and gelatin concentration are evaluated. Gelatin nanoparticles with 200-300 nm can be produced using 20-30 mg mL(-1) of gelatin and a minimum of 7% w/v stabilizer (Poloxamer 407 or 188). Furthermore, methanol and ethanol are good nonsolvents, whereas other nonsolvents such as acetone, isopropyl alcohol, and acetonitrile, result in phase separation and visible precipitates. The entrapment efficiency of fluorescein-isothiocyanate (FITC)-dextran as model drug was determined to 50% with no substantial effect on particle size. 80% of the drug is only released after enzymatic digestion.