Ionic Liquid Drug-based Polymeric Matrices for Transdermal Delivery of Lidocaine and Diclofenac

Abstract

This work prepared and evaluated transdermal patches for delivery of lidocaine and diclofenac. Pectin and Eudragit® NE 30 D were used as a polymer matrix, and glycerin was used as a plasticizer. A lidocaine–diclofenac ionic liquid drug was prepared by ion-pair reactions between the hydrochloride salts of lidocaine and the sodium salts of diclofenac. Characterization properties of blank films and transdermal patches such as mechanical properties, differential scanning calorimeter, thermogravimetric analysis, X-ray diffraction, and scanning electron microscope were evaluated, and the in vitro drug release was studied. It was found that the amount of Eudragit® NE 30 D and the lidocaine–diclofenac ionic liquid drug loading directly affected all characterization properties. Moreover, the crystal characteristics of the drug were found in the transdermal patches when the amount of Eudragit® NE 30 D increased. The thicknesses of the blank films and transdermal patches were in the range of 193–231 µm and 200–233 µm, respectively. The drug contents in transdermal patches were in the range of 1.88–2.11 mg/cm2 and 2.33–2.64 mg/cm2 for lidocaine and diclofenac, respectively. The drug release values of both lidocaine and diclofenac were controlled by the polymer matrix of the transdermal patches. However, the percentage of cumulative drug release decreased when the crystals were in the transdermal patches. In conclusion, the preparation of ionic liquid drug-based polymeric matrices for transdermal delivery of lidocaine and diclofenac provided controlled drug release and will be developed in future studies.