Preparation and in vitro evaluation of gastric-adhesive microspheres of sumatriptan succinate contain chitosan and poly(acrylic acid)

Abstract

Background: Sumatriptan succinate is a 5-HT1 receptor agonist used in the treatment of migraine. It shows low bioavailability due to high hepatic first pass metabolism. Objective: Hence the present work was undertaken to formulate mucoadhesive gastric microparticles of sumatriptan with an objective to improve therapeutic efficacy and the bioavailability. Methods: Microspheres of sumatriptan with polymers (such as sodium alginate, chitosan and/carbomer 934p) were prepared by gelation ionotropic method by using calcium chloride. In the current study formulations with different polymer/s drug ratio were prepared and were characterized by drug loading, loading efficiency, yield, particle size, differential scanning calorimetry (DSC), mucoadhesivity and gastroretentive time. The in vitro release studies were performed in phosphate buffer (pH 6.8). Results: The best polymers ratio was 1:15 and 1:48 (F2 and F'2) with chitosan (as mucoadhesive polymer) and alginate sodium (as insoluble polymer in pH of acidic), respectively. The loading efficiency microparticles F2 and F'2 showed 31.71% and 26.90%, mean particle size 1439.77 and 1611.37 µm, respectively. The DSC showed sumatriptan in the drug loaded microparticles and revealed amorphous form. The results were found that microparticles prepared had more slower release than the commercial tablet (p<o.o5). The microparticles (F2 and F'2) exhibited very good percentage of mucoadhesion and flowability properties. The release of drug was prolonged to 8 h (100%) when incorporated into mucoadhesive microparticles. The results also showed significant higher retention of mucoadhesive microparticles in upper GI tract. Conclusions: Therefore, it may be concluded that drug loaded gastric-mucoadhesive microparticles are a suitable delivery system for sumatriptan, and may be used for improvement of bioavailability and absorption.