Evaluation of Eutectic Temperature and Eutectic Composition of Some of The Binary Mixtures of Local Anesthetics and Terpenes and Their Pharmaceutical Application

摘要

The phase diagrams were constructed for the following binary mixtures, benzocaine:lmenthol,rnbenzocaine:lidocaine, tetracaine:lidocaine and tetracaine:camphor using differentialrnscanning calorimetry (DSC) and an effort was made to evaluate their eutectic composition andrneutectic temperature. The eutectic temperature ranged from 15.9 ℃ for tetracaine:lidocaine torn40.41 ℃ for benzocaine:l-menthol. The melting point depression of the topical drugs has alreadyrnbeen correlated with enhanced transdermal permeation of the drug. In conclusion, DSC can be arnuseful screening tool for selecting appropriate permeation enhancers that form eutectics with therndrugs.