Co-crystals of Gliclazide: Formulation and Characterisation

The main focus of the present study was to explore co-crystallization technique to engineer pharmaceutical co-crystals of poorly aqueous soluble drug- Gliclazide (GLZ) using different GRAS listed coformers; benzoic acid (BA) and itaconic acid (IA). The complexation energy of GLZ and coformers were predicted by Quantum Mechanics method. Co-crystals in 1:2 molar ratios were formulated using solvent evaporation technique using acetone, a class III solvent as a medium for drug and coformer interaction at molecular level. The characteristics of GLZ and resultant co-crystals were evaluated in terms of flowability, drug content uniformity, saturation solubility and in-vitro dissolution studies. Further Fourier transformation infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to identify hydrogen bonding interaction, melting point, crystallinity and surface morphological characteristics of prepared co-crystals respectively. The obtained GLZ co-crystals indicated presence of additional peaks as well as band shifts in the infrared spectrum. Additionally DSC thermograph and XRD confirmed change in crystal lattice. The results of in-vitro dissolution indicated a significant enhancement in the dissolution profiles of both the co-crystals as compared to GLZ. Thus it could be concluded that the co-crystallization technique could be successfully exploited to develop new formulation of GLZ.