INVITRO EVALUATION OF A NEW CONTROLLED-RELEASE VETERINARY DEVICE

The aim of this study was to develop a reservoir constituted by a nonw oven hydrophobic polymeric membrane containing the drug. To allow wate r permeation through this layer, the membrane was treated with a surfa ctant. This form can be easily produced at low cost and the total amou nt of inert material can be as low as 10% of the total weight, avoidin g the disavantages of currently available dosage forms. Dissolution te sts were performed and different parameters were studied (nature of th e polymer, nature and amount of surfactant, membrane surface, nature a nd amount of drug). The amounts of drug and surfactant were found to h ave no effect while the other parameters significantly affected the re lease rate. Finally, an optimal reservoir was designed and studied ove r a 22 day dissolution testing period. The results showed a constant r elease rate of the drug over this period.