Evaluation of physical-mechanical properties of atorvastatin calcium-isonicotinamide cocrystal

Background: Atorvastatin calcium (AC) is a potent antihyperlipidemic drug but poorly water-soluble, so its bioavailability is low. Cocrystallisation of AC with isonicotinamide (INA) is known to increase the solubility of AC so that it is the potential for pharmaceutical formulations. Objective: The study aimed to prepare and evaluate the physical-mechanical properties of the AC-INA cocrystal so that pre-formulation data needed to form pharmaceutical preparation were obtained. Methods: The preparation of the AC-INA cocrystal used the solvent evaporation method, and the characterisation used a powder X-ray diffractometer, differential scanning calorimeter, Fourier Transform Infra-Red spectrophotometer, and scanning electron microscope. Evaluation of physical-mechanical properties includes solid-state properties, moisture absorption, compressibility index, compactibility, and stability. Results: The results indicated that the solid of AC-INA was a cocrystal. AC-INA cocrystal absorbs the moisture of 0.09±0.021% (20 ºC, RH 79.5%), with a compressibility index of 24.99±1.02%. At a temperature of 40 ºC (60 days), the AC in the AC-INA cocrystal decreased by 8.82%, indicating degradation under temperature stress. Conclusions: The AC-INA cocrystal is a non-hygroscopic solid with passable-flow properties. The compactibility characteristics of AC-INA cocrystals are classified as excellent. The AC-INA cocrystal indicated degradation under temperature stress, requiring precautions during storage and formulation.