The mixture will be centrifuged at a suitable speed for a particular period. The mixture will then be filtered. The filtrates will then be diluted with mobile phase then be analysed by HPLC (high-performance liquid chromatography) to determine quantitatively the concentration of the drug.
The intrinsic dissolution rate will be determined using a stationary disk apparatus. The dissolution test will be performed using a USP apparatus 2 (paddle).The temperature will be set at 37◦C and rotation speed at 100rpm will be applied (United States Pharmacopeia 2015). The drug will then be extracted from the mixed media using the liquid-liquid extraction (Ghazal et al., 2015), the upper organic layer will be evaporated to dryness with the use of nitrogen at 60°C and the residue sonicated for few minutes, and then will be analysed using HLPC.
The following analysis will be performed to determine if there was any change in the polymorphic form of the drug or to characterise and provide structure information of the physical state of the dipyridamole. X-ray diffractometry, differential scanning calorimetry and infrared