Development of semi-solid film-forming systems in situ containing anesthetics for the treatment of herpes simplex

Most herpes simplex type 1 infections are asymptomatic, remaining in latent state but the virus may be periodically reactivated. Local anesthetics present pain-relieving, anti-inflammatory and antiviral action. The project aims at the development of a polymer composition containing local anesthetics for the treatment of cold sores. Three compositions containing prilocaine hydrochloride and lidocaine hydrochloride drugs, associated at a ratio of 1:1, in different concentrations, were submitted to evaluation of in vitro drug release profiles, continuous flow rheological test and bioadhesion test. Results showed that the in vitro release profile of both drugs were similar and that the system used did not influence drug release at the end of 48h of evaluation. All three compositions showed pseudoplastic behavior and the increase of the drug content in the compositions led to the increase of the initial viscosity. The bioadhesion was directly proportional to the percentage of drug present in the formulations.