Sulpiride microemulsions as antipsychotic nasal drug delivery systems: In-vitro and pharmacodynamic study

Abstract The present study aimed to develop microemulsion (ME) formulae for nasal delivery of sulpiride with high drug concentration to overcome sulpiride low oral bioavailability. Different oils, surfactants (S) and co-surfactants (CoS) were screened for the highest sulpiride solubilizing capacity. Glycerylmonooleate (GMO), Labrafil and Avocado were chosen as oily phases for ternary phase diagram construction. As nasal cavity accommodates limited administration volume, higher drug solubility and ME area (A T %) were used as assessment criteria. ME systems of the highest drug solubilities were subjected to physicochemical characterization such as drug content, pH, refractive index (RI), percent transmittance (%T), in-vitro release and ex-vivo permeation through the sheep nasal mucosa. Sulpiride solubility increased to 43.35 mg/ml with drug content more than 97%. The pH ranged from 4.25 to 5.75 while RI and %T values indicated that o/w type ME was formed. The pharmacodynamic performance, antipsychotic activity of sulpiride, concluded that intranasal ME is an effective alternate therapy for schizophrenia.