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

Abstract

In this research paper, we describe a study on the inclusion complex formation between Metformin hydrochloride (MF) and beta-cyclodextrin (β-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 β-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 β-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 1HNMR techniques. All the instrumentation techniques revealed that microwave and co-precipitation methods form true inclusion complexes. Different parameters such as apparent molar volume (Vϕ), partial molar volume at infinite dilution (Vϕ0) 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, β-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/β-CD inclusion complexes.