This study aimed to find out the mechanism of release of active medicinal substances from ointments, creams, and gels, and the effect of changing the properties and texture of these preparations through the excipients that form them on the release because there is no longer any doubt in our time about the effect shown by the cofactors (excipients). There is an observation that the decrease in the amount of lidocaine HCL released is due to the lidocaine base, which is transported through the membrane by absorption on the surface of the oily droplets. Too large, which contributes to the transport of large quantities of lidocaine ready-to-transport basis. When the external phase is oily, the contact surface area is less, and the oily phase's movement is limited. Thus, oil/water creams release lidocaine better than water/oil creams.
Faculty of Pharmacy, Aljazeera Private University.