Solid lipid nanoparticles (SLN) for controlled drug delivery II. drug incorporation and physicochemical characterization

Solid lipid nanoparticles (SLN) are a colloidal carrier system for controll ed drug delivery. The lipophilic model drugs tetracaine and etomidate were incorporated to study the maximum drug loading, entrapment efficacy, effect of drug incorporation on SLN size, zeta potential (charge) and long-term p hysical stability. Drug loads of up to 10% could be achieved whilst simulta neously maintaining a physically stable nanoparticle dispersion. Incorporat ion of drugs showed no or little effect on particle size and zeta potential compared to drug-free SLN. The optimized production parameters previously established for drug-free SLN dispersions can therefore be transferred to d rug-loaded systems to facilitate product development.