Long-Term Stabilized and Highly Soluble Bezafibrate-Gliclazide Co-Amorphous Binary System

Abstract

Metabolic syndrome (MS) has a high prevalence, with an estimated one-quarter of the world population affected by this pathological condition. Among the diseases of this syndrome are dysregulation of lipids, hypertension, and insulin resistance. Unfortunately, available drugs in the market used for treating MS, as almost 75% of all drugs, are highly insoluble, presenting a significant demand for strategies to increase their solubility. Taking advantage of the fact that drugs in the amorphous state can provide a solubility enhancement, a new drug-drug co-amorphous (CoA) formulation to potentially simultaneously treat two or more MS conditions was explored, combining the co-formers Bezafibrate (BZT) a lipid-regulating drug, and Gliclazide (GZD) a hypoglycemic agent. A phase diagram was constructed to characterize the binary system's thermal properties, including glass transition temperatures of all compositions studied. The formulations were characterized by FTIR; redshifts of IR bands from 1547 to 1538 cm^–1 and 1717 to 1609 cm^–1 were observed due to the formation of intermolecular interactions, such as hydrogen bonds. The co-amorphous binary systems lead to an increase in the solubility of both BZT and GZD; specifically, for the composition x_BZT = 0.5, the increase was 2.1× for BZT and 1.5 times for GZD while for x_BZT = 0.7 an increase of 4× of BZT was achieved. The structural stability of the samples was verified by XRD and DSC, showing long-term stability retention of the amorphous state for more than eight years. The enhanced solubility and stability of the co-amorphous systems make them potential formulations for regulating lipids and lowering glycemia.

Graphical Abstract