title: Preparation and crystallographic analysis of gliclazide polymorphs.
abstract: Since the introduction of gliclazide in the pharmaceutical industry, a large number of research groups have been engaged in various investigations aiming to enhance its biomedical application. But, very limited efforts have been made to study polymorphism of gliclazide. Therefore, this study focuses on solvent-induced polymorphism of gliclazide and its characterization by thermal methods. Three polymorphs namely, Form-I, II and III and an amorphous powder were produced from different solvents and solvent mixtures. Crystals were analyzed using infrared spectroscopy, differential scanning calorimetry, X-ray powder diffraction and single crystal x-ray diffraction. Polymorph Form-I is found to exist in centro-symmetric triclinic P-1 space group and has endothermic peak at 162.93°. Form-II has endothermic peak from 171.2° to 172.35° and exists in centro-symmetric monoclinic P21/a space group while Form-III has endothermic peak from 168.93° to 169.86° and exists in centro-symmetric monoclinic P21/n space group. The equilibrium solubility values of Form-I, II, III and the amorphous form were 0.4825±0.025, 0.2341±0.042, 0.2581±0.038 and 0.5213±0.072 mg/ml, respectively. The Form-I has relatively higher solubility and similar to that of amorphous gliclazide. Form-II and Form-III are relatively most stable and least soluble. However, there was no remarkable difference in their aqueous solubility under the conditions in which study was conducted.
authors.affiliation: Department of Pharmacognosy, KLEU's College of Pharmacy, Bangalore-560 010, India.
authors.forename: A J
authors.initials: AJ
authors.lastname: Rajamma
authors.affiliation: Department of Pharmaceutics, Acharya and BM Reddy College of Pharmacy, Bangalore-560 090, India.
authors.forename: S B
authors.initials: SB
authors.lastname: Sateesha
authors.affiliation: Department of Pharmaceutics, Nargund Research Foundation, Bangalore-560 085, India.
authors.forename: M K
authors.initials: MK
authors.lastname: Narode
authors.affiliation: Department of Pharmaceutics, Acharya and BM Reddy College of Pharmacy, Bangalore-560 090, India.
authors.forename: V R S S
authors.initials: VR
authors.lastname: Prashanth
authors.affiliation: Department of Pharmaceutics, Acharya and BM Reddy College of Pharmacy, Bangalore-560 090, India.
authors.forename: A M
authors.initials: AM
authors.lastname: Karthik
keywords: Gliclazide polymorph; centro-symmetric; equilibrium solubility; monoclinic; single crystal X-ray diffraction; triclinic