Vinay Umesh Rao

The poor aqueous solubility of Glimepiride is the major factor limiting its oral bioavailability.  The objective of the work is to enhance the solubility of Glimepiride, there by its bioavailability by using solid dispersion technique. Solid dispersions of Glimepiride were prepared by using Poly vinyl Pyrrolidone (PVP K30), by solvent evaporation method in different ratios of 1:0.5, 1:1, 1:3, 1:5 respectively and evaluated for its in vitro & in vivo release along with Mdsc & FTIR. The equilibrium solubility of solid dispersions was determined in water to study the effect of PVP K30 on solubility of Glimepiride. In Vitro dissolution studies were conducted in water from solid dispersions equivalent to 4 mg of Glimepiride. Protocol bound in vivo studies were conducted in non diabetic rats with the best formulation. Two groups of rats (6 rats in each group) were orally fed Glimepiride as plain drug dispersion (control group) & as drug: PVP K30 solid dispersion (test group). The fall in blood glucose level was monitored over 24 hours. Successful conversion of the crystalline Glimepiride to amorphous solid dispersion was achieved at 1:5 level of drug to PVP K30 (F4). The solid dispersion prepared with PVP K30 at 1:5 level (F4) showed a 4 folds enhancement in aqueous solubility of the drug. So the in vivo studies conducted with 1:5 drug to PVP K30 (F4) solid dispersion, the best formulation, it was observed that the fall in the test group is significantly faster and more intense as compared to the control group. The above study shows that solid dispersion of Glimepiride offers an simple and attractive solution to increase the solubility of the poorly water soluble drug and thereby improve its oral bioavailability. Key words: Glimepiride, Poly vinyl Pyrrolidone (PVP K30), Solid dispersions (SD)

In the present study compared and evaluated the three granulation process for controlled release antidiabetic drug of Gliclazide. The effect of three different polymers on the in-vitro dissolution profiles of Gliclazide controlled release tablet was studied. Later combinations of polymers were used and the tablets were prepared by using wet, dry and MADG (Moisture Activated Dry Granulation) process. The study was carried out using full factorial designs of experiments. The release rate of 5 to 6 mg%/ hour was targeted and the effect of the polymers on drug release over 24 hours was evaluated. The DOE experiments have shown that when the combination of polymer is used, the total polymer concentration should be in a narrow range of 32.4% w/w to 37.5% w/w in order to achieve the target dissolution profile for Gliclazide. The effect of three granulation process on the tablet properties and drug release were studied. Wet granulation and MADG process were compared. Finally MADG process is showing better results when compared with other process.