Novel surface modified solid lipid nanoparticles as intranasal carriers for ropinirole hydrochloride: application of factorial design approach.

Present investigation deals with intranasal delivery of ropinirole hydrochloride (ROPI HCl), loaded in solid lipid nanoparticles (SLNs). Prime objectives of this experiment are avoidance of hepatic first pass metabolism and to improve therapeutic efficacy in the treatment of Parkinson's disease. SLNs were fabricated by emulsification-solvent diffusion technique. A 3(2)-factorial design approach has been employed to assess the influence of two independent variables, namely Pluronic F-68 and stearylamine concentration on particle size, ζ-potential and entrapment efficiency of prepared SLNs. Prepared samples were further evaluated for in vitro drug diffusion, ex vivo drug permeation, histopathological and stability studies. Differential scanning calorimetry analysis revealed the encapsulation of amorphous form of drug into lipid matrix, while scanning electron microscopy studies indicated the spherical shape. Fabricated SLNs had shown no severe signs of damage on integrity of nasal mucosa. Release pattern of prepared drug-loaded sample was best fitted to zero-order kinetic model with non-Fickian super case II diffusion mechanism. In vivo pharmacodynamic studies were carried out to compare therapeutic efficacy of prepared nasal formulation against marketed oral formulation. Results of analysis of variance demonstrated the significance of suggested model. Three-dimensional response surface plots and regression equations confirmed the corresponding influence of selected independent variables on measured responses. Our findings suggested the feasibility of investigated system for intranasal administration.