Physicochemical characterization of gliclazide-macrogol solid dispersion and tablets based on optimized dispersion.
BACKGROUND
This study investigated the physical interaction of gliclazide (GLC) with a hydrophilic carrier, that is, macrogol [polyethylene glycol (PEG)]. Different molecular weights of PEG (4000, 10,000, and 20,000) were used in different drug : carrier weight ratios (1 : 1, 1 : 2, 1 : 5, and 1 : 10).


METHODS
Preliminary screening was done by phase solubility studies to characterize the liquid state interaction between the drug and the carrier. Solid dispersions (SDs) of GLC and PEG in different ratios were prepared by fusion technique and by physical mixing. The solid-state interaction between the drug and the carrier was examined by performing differential scanning calorimetry and Fourier transform infrared spectroscopic studies. SD with satisfactory characteristics was selected for the formulation of tablets by wet granulation method and compared with the commercial brand for in vitro dissolution.


RESULTS
It was evident from phase solubility studies that the drug solubility increased linearly with increasing PEG concentrations. In vitro dissolution of GLC improved significantly in the SDs prepared by fusion method as compared with the original drug and physical mixtures. Scanning electron microscopy images showed well-defined changes in the surface topography of GLC, thus confirming the effective formation of a fused binary system. The SD tablets showed a significant improvement in the drug release profile than that of the commercial brand.


CONCLUSIONS
It was thus concluded that SD formulations of GLC can be successfully used to design a solid dosage form of the drug, which would have significant advantages over the current marketed tablets.
Khattab
Ibrahim S
IS
Department of Pharmaceutics, Faculty of Pharmacy, Kuwait University, Safat, Kuwait. khattab@hsc.edu.kw
Nada
Aly
A
Zaghloul
Abdel-Azim
AA
D002152:Calorimetry, Differential Scanning; D055598:Chemical Phenomena; D004337:Drug Carriers / Q000008:administration & dosage / Q000032:analysis / Q000737:chemistry*; D004339:Drug Compounding; D005907:Gliclazide / Q000008:administration & dosage* / Q000032:analysis / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D007004:Hypoglycemic Agents / Q000008:administration & dosage* / Q000032:analysis / Q000737:chemistry*; D007700:Kinetics; D008970:Molecular Weight; D009994:Osmolar Concentration; D011092:Polyethylene Glycols / Q000737:chemistry*; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D013535:Suspensions; D013607:Tablets
D004337:Drug Carriers; D007004:Hypoglycemic Agents; D013535:Suspensions; D013607:Tablets; D011092:Polyethylene Glycols; D005907:Gliclazide