Pharmaceutical Cocrystals of Nitrendipine with Improved Solubility and Dissolution Characteristics

Nitrendipine is used in the treatment of hypertension. It comes under BCS class II and has a poor dissolution rate and water solubility. In the present study, pharmaceutical cocrystals of nitrendipine with 4-hydroxy benzoic acid were prepared using crystal engineering, an innovative method for improving solubility. 4-hydroxy benzoic acid was used as a co-former to prepare cocrystals of nitrendipine in the ratios of 1:1 and 1:2. Nitrendipine cocrystals were prepared using cooling co-crystallization. The prepared cocrystals were assessed for in vitro dissolution characteristics, saturation solubility, and stability. Analytical measures such as Differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and powder X-ray diffraction (PXRD), and differential scanning calorimetry (DSC) were also used to analyze cocrystals for their purity and to confirm the formation of cocrystals. By using the cooling co-crystallization process, nitrendipine and 4-hydroxy benzoic acid crystallize together in an equimolar ratio. When compared to pure nitrendipine, the nitrendipine - 4-hydroxy benzoic acid cocrystals have a dissolving rate that is 3-4 times faster. Co-crystallization may increase nitrendipine's water solubility and rate of dissolution, which could be a solution to the drug's bioavailability issue. X-ray diffraction revealed crucial hydrogen bonding and interactions, while differential scanning calorimetry confirmed improved dissolution kinetics and higher equilibrium solubility in the optimized nitrendipine cocrystal formulation. Nitrendipine's solubility and dissolution rate are improved by the cocrystal formulation, according to the results of research on its solubility, dissolution, and stability.