The Effect of Polymers on the Aqueous Solubility and Dissolution Behavior of Gliclazide-ß-Cyclodextrin Complex
By Sateesha SB, Prakash Rao B, Rajamma AJ and Nargund LVG
The rationale of this study was to enhance solubility and dissolution rate of Gliclazide(GLD) by complexation with ß-cyclodextrin (ß-CD) and subsequent disperson with water-soluble polymers. The water-soluble polymers used were Hydroxypropyl methylcellulose 5cps, Polyvinylpyrrolidone K30, Avicel pH101, Polyethylene glycol 4000 and Croscarmellose sodium. The GLD-ß-CD complex was prepared at the concentration of 1:1.5 molar ratios by co-precipitation method and the polymers were added at the concentration of 5%w/w to the complex by kneading. The binary system was characterized by differential scanning calorimetry, IR spectroscopy and X-ray diffractometry. Phase solubility studies revealed that the complexation with ß-CD increases the solubility of drug. All the ternary systems showed higher dissolution efficiency compared to the binary system. The Gibbs free energy change (?Gtrº) values are negative for all the binary and ternary systems, indicating the spontaneous nature of the drug solubilization. The investigated polymers increased the dissolution rate of the drug in the order of Croscarmellose sodium> PEG 4000 >Avicel pH101> HPMC 5cps > PVP K30. The increase in the dissolution rate of GLD might be related to the increase of complexation efficiency and solubilizing effect of ß-CD in presence of water-soluble polymers.
Key Words : Gliclazide; Complexation; Solubility; Gibbs free energy change.
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