Zanco Journal of Medical Sciences (Aug 2024)
Optimization of solid dispersion technique and gliclazide to carrier (PVP K30) ratio for solubility enhancement
Abstract
Background and objective: Poorly water-soluble dugs provide less dissolution rate and bioavailability; hence, it minimizes the pharmacological effect of orally administered medications. Gliclazide is a sulfonylurea antidiabetic medication of the second generation, used to treat type II diabetes mellitus. It belongs to the class II drugs of biopharmaceutic classification system, indicating that it has high permeability and poor aqueous solubility. The aim of this study is to determine an optimum solid dispersion method and drug to carrier ratio to improve the solubility of gliclazide. Methods: Solid dispersions of gliclazide were formulated with polyvinyl pyrrolidone K30 using various drug to carrier ratios (1:1, 1:3, and 1:5) by utilizing kneading and solvent evaporation methods. Solubility and dissolution rate of solid dispersion formulas were compared with pure drug and co-ground mixtures. The formulations were further evaluated in terms of percentage of yield, drug content, FTIR, SEM, DSC, and XRD studies. Results: The highest solubility improvement of gliclazide was obtained at the ratio 1:5 of gliclazide and PVP K30 utilizing solvent evaporation method, solubility increased about 2.54 folds (98.299 ± 5.77 µg/ml) as compared to pure gliclazide (38.739 µg/ml). Meanwhile, the greatest improvement in gliclazide dissolution rate was observed in the same solid dispersion formula that was about 105.76 % after 30 minutes. FTIR demonstrated no unwanted interaction between the drug and carrier. While, SEM, DSC, and XRD showed crystallinity of the drug was minimized and converted to amorphous form in solid dispersion formula. Conclusion: Based on the investigations of this study, it can be concluded that the drug to carrier weight ratios and preparation methods had the influence on the drug solubility and the release rate. The obtained data revealed that the solvent evaporation is the best method of solid dispersion for enhancing gliclazide solubility using PVP K30 with the ratio 1:5 of the drug and carrier.
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