ABSTRACT:
Mucoadhesive buccal tablets of sumatriptan succinate were prepared with an objective of enhanced bioavailability using chitosan in varying concentration alone and in combination with natural gums like xanthan and acacia as secondary polymers by direct compression method. The preformulation study using FTIR spectroscopy revealed the compatibility of drug and polymer. The tablets were evaluated for hardness, thickness, weight variation, friability and drug content concluded that all these parameters were in acceptable range of pharmacopoeial specification. The tablets were studied for surface pH, swelling index, in vitro drug release, ex vivo residence time, mucoadhesion, ex vivo permeation and also the effect of chitosan concentration on these parameters was studied. The surface pH of the tablet was from 6.68 to 7.04 which fall in the range of salivary pH and all the tablet showed ex vivo residence time of 3.25 to 4.35 h indicated good adhesive capacity of tablet. The buccal tablet showed good swelling of >70% up to 7 h maintaining the integrity of formulations. The in vitro release of sumatriptan succinate was extended 4-6 h, if chitosan alone and in combination with secondary polymer xanthan gum was used, while chitosan along with gum acacia prolonged the release up to 8 h. The in vitro release obeyed zero order kinetic with mechanism of release was erosion followed by non-Fickian diffusion. All the tablets showed good mucoadhesive strength of 4.51 to 8.01 g and was enhanced by the addition of secondary polymers. As the concentration of chitosan increased there was significantly (p<0.05) decrease in swelling index and mucoadhesion. The ex vivo permeation revealed that chitosan enhanced the flux and permeability coefficient of sumatriptan succinate and as the concentration of chitosan increased there was significantly (p<0.05) increased in the flux. Hence chitosan and other hydrophilic polymers can be used to prepare mucoadhesive buccal tablets of sumatriptan succinate having prolonged therapeutic effect with enhanced bioavailability.