Περίληψη:
Hydrophobie matrices were prepared using Eudragit RL 100. Flurbiprofen was used as a model drug, with sorbitol as a diluent. The effect of adding each of five surfactants (sodium lauryl sulphate, sodium taurocholate, cetylpyridinium chloride, cocamidopropyl betaine (CDB) and cetrimide) individually to the matrix was investigated. To investigate the mechanism by which the rate of drug release was increased following the incorporation of surfactants, experiments were undertaken to assess the wettability of the different formulations, and to measure drug release in the presence of submicellar and micellar concentrations of the surfactants. Three mechanisms were proposed by which drug release could be increased following the addition of surfactants: improved wetting, solubilisation, and the dissolution of the soluble surfactants to form pores in the matrix. When the surfactant was added to the dissolution fluid, only one surfactant (CDB) did not result in an increase in drug release; for the other surfactants a minor increase in drug release was observed. Therefore, in most cases, wetting plays a small role in aiding dissolution. There was no significant change in release rate when the experiment was performed in the presence of either sub-micellar or micellar concentrations of the surfactants, thus solubilisation of the drug does not seem to be implicated in the drug release mechanism. The most significant increase in drug release rate was caused by incorporating the most soluble surfactants (sodium taurcholate and cetrimide) within the matrix. As the increase was significantly greater than could be explained by wetting alone, it must be concluded that for these matrix systems the major mechanism by which surfactants increase the dissolution rate is by the formation of pores to aid the access of the dissolution fluid and egress of the dissolved drug. It is also possible that the presence of the relatively concentrated surfactant solution in the wetted tablet would reduce interparticle adhesion and thereby speed drug release rate as a result of an increased disintegration. © 1991.
Συγγραφείς:
Efentakis, M.
Al-Hmoud, H.
Buckton, G.
Rajan, Z.
