Paliperidone-Loaded Mucoadhesive Microemulsion in Treatment of Schizophrenia: Formulation Consideration

This paper describes formulation considerations and in vitro evaluation of a microemulsion drug delivery system designed for intranasal administration of Paliperidone. Drug-loaded microemulsions were successfully prepared by a water titration. Prepared formulations were subjected to physicochemical characterization, and evaluated for in vitro diffusion, nasal cilio toxicity, and in vitro mucoadhesion. The microemulsion, containing 4 % oleic acid, 30 % surfactant mixture of [Labrasol/Cremophor RH 40 (1:1)]/[Transcutol P] (3:1) and 66 % (wt/wt) aqueous phase, that displayed a 99.93 % optical transparency, globule sizes of 20.01 +/- 1.28 nm, and a polydispersity index of 0.117 +/- 0.034 was selected for the incorporation of polyelectrolytic polymer (polycarbophil) as the mucoadhesive component. The mucoadhesive microemulsion formulation of Paliperidone that contains 0.5 % by weight of polycarbophil displayed higher in vitro mucoadhesive potential (18.0 +/- 2.5 min) and diffusion coefficient (3.83 x 10(-6) +/- 0.019 x 10(-6)) than microemulsion. Also, they were found to be free from nasal ciliotoxicity and had stability for 6 months. The in vitro studies demonstrated the potential of developing mucoadhesive microemulsion formulation for intranasal delivery of Paliperidone.