Formulação transdérmica contendo enrofloxacino: desenvolvimento e testes preliminares para avaliação da estabilidade físico-química

Abstract

Enrofloxacin is an antimicrobial belonging to the fluoroquinolones class and is used in veterinary practice in the treatment of respiratory diseases and gastrointestinal infections in small and large animals. Enrofloxacin is available commercially in tablete and injectable form and is not found in the semisolid form. Among the semi-solid formulations, that which allows transdermal administration is shown to be effective in administering veterinary medicinal products, since it does not have the drawbacks of oral administration. However, in addition to the determination of cutaneous permeation and bioavailability of this type of pharmaceutical form, studies involving pharmacotechnical development are required together with stability studies of both the inserted active as well as the base used in the formulation. Among the bases available for transdermal administration of active substances we can mention Pentravan®, which is an oil-in-water emulsion that allows transdermal permeation, since it is a phospholipid matrix. The present study emphasized the characterization and preliminar evaluation of the physical-chemical stability of a semi-solid formulation of enrofloxacin 0.5% using the Pentravan® base as vehicle. Different solvents were evaluated for solubilization of enrofloxacin and subsequent incorporation into the base. The characterization of the formulation was performed from the following tests: visual aspect, particle size, rheological profile, spectral profile (in the region of the Middle Infrared), differential scanning calorimetry profile (DSC) and microscopic analysis. The stability of the formulation was preliminarily evaluated after storage of the formulation at temperatures of 30 ° C and 45 ° C and determination of the rheological profile every 10 days for a period of 30 days. In the present study it can be concluded that the mode of incorporation as well as the solubilizing solvent of the drug influenced the characteristics of the formulation, changing important aspects such as particle size and viscosity.