Designing, Critical Characterization, and Analytical RP-HPLC Method Development for Simultaneous Quantifications of Azelnidipine and Telmisartan Cocrystal

Introduction: Azelnidipine and telmisartan are hypertensive medicines that belong to the BCS class II category and have low solubility and high permeability. Crystal engineering was employed to create unique cocrystals of azelnidipine with other drug molecules. The purpose of the study was to improve solubility and dissolution rate through the cocrystal approach and to develop and implement a selective, sensitive, and accurate RP-HPLC method for simultaneous analysis of both drugs in cocrystals. This approach addresses key pharmaceutical challenges in the research. Method: Synthesis of Azelnidipine cocrystal with Telmisartan was achieved using solvent evaporation and solvent ultrasonication techniques, respectively. These cocrystals were characterized by various techniques such as 1H-13C NMR, spectroscopy, FT-IR, DSC, and PXRD, which demonstrated the hydrogen-bond interactions and the purity of the drug molecules. The confirmed RP-HPLC method may be applied efficiently for the simultaneous detection and quantification of both drugs in cocrystal forms at 254 nm. Result: The method can be used to investigate physicochemical parameters, such as solubility and in vitro dissolution research. Regression equations were derived based on different kinetic models, including zero-order, first-order, Higuchi, and Weibull models. All prepared co-crystals were characterized using DSC, FTIR, PXRD,1H NMR,13C NMR, 2D HSQC NMR, and SEM. The characterization data support the formation of intermolecular hydrogen bonds between the drugs. Discussion: The confirmed RP-HPLC method may be applied efficiently for simultaneous detection and quantification of both drugs in cocrystal forms at 254 nm. It can be used to investigate physicochemical parameters, such as solubility, and to support in vitro dissolution research. The solubility profiles of Azelnidipine and Telmisartan were found to improve in cocrystal form. Conclusion: Co-crystallization improved the solubility, dissolution rate, and photostability of Azelnidipine and Telmisartan in cocrystal form.