Sulpiride gastro-retentive floating microsponges; analytical study, in vitro optimization and in vivo characterization
Sulpiride (SUL), anti-dopaminergic drug, has a specific site for absorption located in the upper portion of the gastrointestinal tract hence, its oral delivery represents a challenge regarding SUL absorption and bioavailability. So, a gastro-retentive oral platform of SUL was developed to increase its gastric residence time, release SUL at a controlled rate in the stomach and consequently, enable it to reach its specific absorption site. Floating microsponges were prepared via quasi-emulsion solvent diffusion method and characterised for their physico-chemical properties. In addition, Taguchi design of experiment was utilised to optimise some independent variables affecting microsponges performance. The optimised SUL microsponges showed a yield of 79.82 ± 2.37%, an encapsulation efficiency of 89.11 ± 2.28% and in vitro time for floatation of 8.0 h. Additionally, pharmacokinetics were investigated in rabbits and compared with the commercial SUL formulation, Dogmatil® capsules. Optimised SUL microsponges showed a significantly (p < .05) higher Cmax, AUC and 2-fold increase in oral bioavailability compared with the commercial product. Moreover, the optimised SUL microsponges remained present in the stomach up to 8.0 h post administration when viewed via X-ray radiographs in rabbits. It could be concluded that the floating microsponges could be useful as an oral platform to enhance the sulpiride absorption and bioavailability.