In-vitro release

Glimepiride loaded polymeric blend matrices were prepared using hydrogel forming polysaccharide like agar, isabgol, aloe vera and gelatin by solution blending method. The polymeric blends were characterized by Fourier-transform infrared spectroscopy revealed that there was no reaction between drug and polymers. The surface morphology of prepared polymeric blends was studied by scanning electron microscopy which suggested that polymeric blend matrices have smooth/rough surface with vacuoles. All the polymeric blend matrices were evaluated for weight variation, hardness, thickness and drug content which suggested that all these parameters were uniform as the total amount of the polymers was fixed to 10%. The polymer blend matrices show good hardness of more than 8 kg/cm2 and drug content more than 95 % suggested that the solution blending method used was suitable for the preparation of polymeric blends. The polymeric blend showed good swelling in the range of 244.12 to 411.22 % within 8 h maintaining integrity of formulation. The in vitro release of the glimepiride was rapid in phosphate buffer pH 6.8 with more than 81.96% released within 8 h. Increases in the amount of agar enhance the in vitro release whereas increases in the amount of gelatin decrease the release of glimepiride. Hence the polymeric blends prepared with agar or gelatins with other polysaccharide as binary or ternary system extend the glimepiride up to 8 h and can be used for effective management of diabetes and also presence of aloe vera may provide synergistic hypoglycemic effect.

The present study involves preparation and evaluation of floating microsphere of Captopril as model drug for prolongation of gastric residence time. the different gas forming agents are used such as sodium bicarbonate and calcium carbonate. The microsphere were prepared by Ionotropic gelation technique using polymers Sodium alginate along with HPMC (K4M) and Ethyl cellulose. The microsphere was evaluated for angle of repose, bulk density, tapped density, Carr’s index, Hausner's ratio, percent yield and drug entrapment. The shape and surface morphology of prepared microsphere were characterized by optical and scanning electron microscopy, respectively. In-vitro drug release studies were performed by using an USP dissolution test apparatus (type I) at 37±0.5ºC and 50 rpm speed.  To study the release behaviour, kinetic analyses were performed on the optimized formulation. The dissolution data were fitted to zero order, first order, matrix, Hixson-Crowell, Peppas model. The prepared microsphere exhibited prolonged drug release (~ 12 hr) and remained buoyant for > 12 hr.  The optimized formulations H3, H6 were kept for short term stability study. The conditions for stability study were 40ºC and relative humidity of 75% from the study; it was observed that there is no significant change in drug entrapment and drug release rate. Key-words: Floating microsphere, Captopril, In-vitro release, HPMC (K4M), Ethyl Cellulose