Synthesis, characterization and studies on host-guest interactions of inclusion complexes of metformin hydrochloride with β-cyclodextrin

In this research paper, we describe a study on the inclusion complex formation between Metformin hydrochloride (MF) and beta-cyclodextrin (beta-CD) in order to improve the sustained release, dissolution and oral bioavailability of the drug MF. Metformin hydrochloride is a drug used for treating non-insulin-dependent diabetes mellitus and for polycystic ovary syndrome. The host-guest solid inclusion complex of MF with beta-CD is prepared by Microwave irradiation method along with conventional methods such as physical mixture, kneading method and co-precipitation method. The phase solubility studies suggested the 1:1 stoichiometry and revealed the solubility of MF is enhanced during the inclusion complex formation between MF and beta-CD. The value of the apparent stability constant was found to be 61.11 M-1. The rate of dissolution of the drug was found to be highest (95% in 60 min) for the inclusion complex prepared by microwave irradiation method. Inclusion complexes were characterized by using FTIR, FESEM, PXRD, DSC and (HNMR)-H-1 techniques. All the instrumentation techniques revealed that microwave and co-precipitation methods form true inclusion complexes. Different parameters such as apparent molar volume (V-phi), partial molar volume at infinite dilution (V-phi(0)) have been determined by using the experimental density data. Apparent molar and partial molar parameters concerning volumetric predict that the host-guest interactions prevailed in the ternary system of MF,beta-CD and distilled water. Microwave irradiation completes the process of inclusion complex formation in a very short duration of time and is a more environment-friendly method. Thus microwave irradiation can be utilized as an advanced, time-saving and cost-effective method for the generation of MF/beta-CD inclusion complexes. (C) 2019 Elsevier B.V. All rights reserved.