Formulation and characterization of nimodipine in situ gels for oral delivery

Abstract

To formulate and evaluate Nimodipine floating in situ gels for oral delivery in order to enhance its residence time and to overcome the inherent drawbacks associated with conventional oral formulations like tablets and capsules. As Nimodipine is a BCS Class II drug, first Nimodipine solid dispersions were made to enhance its solubility. Solvent evaporation method was employed for this. Then in situ gel formulations were prepared using the optimized solid dispersion formulations. Sodium alginate and HPMC K100M were used as gelling agent and viscosifying agent respectively. In vitro characterization like gelling capacity, floating time, drug content, viscosity, % cumulative drug release studies were performed. In vivo pharmacokinetic parameters were studied. Infrared spectroscopy ruled out drug-excipient interactions. The release pattern showed a burst effect in the first 30 minutes followed by a moderate steady release for 12 hours. Stability testing indicated that the formulation remained stable with no significant changes in percent cumulative drug release and viscosity. In vivo pharmacokinetic study results were satisfactory. A promising, stable, sustained release, liquid oral floating in-situ gelling systems of Nimodipine were successfully developed and evaluated. Oral in situ gels could be good alternative for geriatric and pediatric population who have trouble swallowing solid medications.