In vitro study of the microneedles system appicability for topical anesthesia in swine oral tissues.

Abstract

Recent studies have demonstrated the use of microneedles for increasing skin topical anesthesia and absorption of topically applied drugs aiming at systemic action. The objective of the use of microneedles is to cross the stratum corneum painlessly, improving the absorption of drugs in topical route administration. This system could be useful for improving topical anesthesia efficacy in dentistry. Thus, the aim of the present study is to evaluate the applicability of the microneedle system in vitro in swine oral tissues aiming at future use in vivo in volunteers. The following analysis will be performed: histological characterization of micropores created on palatal mucosa by light microscopy and confocal microscopy following mucosal perforation with different microneedle sizes (0.2, 0.5 and 1 mm); and evaluation of the micropores (created by different microneedles sizes described previously) influence in the permeation parameters and retention of a topical anesthetic formulation. The in vitro permeation and retention studies will be performed at Franz type diffusion cells with the topical anesthetic EMLA® (AstraZeneca - Brazil). After permeation experiments, retention of local anesthetics into the tissue will be analyzed. Quantification of local anesthetics in permeation and retention studies will be performed by High Performance Liquid Chromatography (HPLC). The microneedle system that will to be used in the present study is the Dermaroller® (Microagulhas Dermaroller® - Dermaroller Deutchland S.A.R.L. Alemanha).