Inhibition of Crystallization in Highly Loaded Drug Bilayer Topical Patch using Lipid-Based Cosolvent

A topical patch with highly loaded drug may lead to instability by forming recrystallization and causing gritty and dry patch also has implications for the rate of drug absorption through the skin and patch adhesion strength. The idea of keeping the drug to be molecularly dispersed will prevent the drug from being recrystallized. In this research, the lipid-based cosolvent was used to dissolve the drug as well as to keep the drug molecularly dispersed. Sodium diclofenac was used in this research as a drug model to be loaded into the topical patch. The current study aimed to develop topical patch formula and to evaluate the effect of using lipid-based cosolvent in preventing recrystallization. The patch was prepared using solvent casting method. The evaluation of the effect of lipid-based cosolvents in preventing drug recrystallization was carried out using x-ray diffraction method. The result showed that the addition of lipid-based cosolvents to the highly loaded sodium diclofenac topical patch formulation was able to prevent crystallization after storage at room temperature for six days.