Estudo in vitro da cinética de desorção de doxiciclina e tetraciclina impregnadas a membranas de colágeno utilizadas como dispositivos de liberação medicamentosa local

Abstract

Although mechanical treatment promotes satisfactory results in the control of periodontal disease, complete removal of the bacterial biofilm is rare. Local antimicrobials like doxycycline and tetracycline have therefore been proposed as coadjuvants of conventional treatment. The objective of this work is to evaluate, in vitro, the desorption kinetic of doxycycline and tetracycline incorporated into two controlled release devices (CRDs) of collagen: DOX and TET. For this, the devices were introduced to 25ml of phosphate buffer and maintained in a thermostated bath at 36,5 oC for 15 days. The solutions were analyzed in a spectrophotometer (Shimadzu, model UV 2501 PC) at wavelength 275nm, at intervals of 1, 2, 4, 8, 12, 24, 48, 96, 168, 240 and 360 hours after the start of the experiment. Next, calibration curves were constructed for the doxycycline and tetracycline in phosphate buffer. For the desorption kinetic study, first order models were applied, through neperian logarithm graphs (In) of drug mass released versus time. The results demonstrate that the drugs were released for 48 hours, with higher speed of desorption observed in the first four hours. TET released a higher quantity of antimicrobial than DOX in all the periods analyzed.