Poly(Methacryloiloxy-o-Benzoic Acid) as Drug Carrier for Controlled Release
<p>Poly(methacryloiloxy-<em>o</em>-benzoic acid), an amphiphilic weak polyelectrolyte was bound by secondary forces to cationic drugs (propranolol. HCl and labetalol.HCl) to form water-insoluble complexes that release the bound drug only in ionic media. Compressed tablets were prepared from the polymer-drug complexes formed. The complex with propranolol suffers a fast release in simulated gastric fluid (pH 1.2), but presents a diffusion controlled release at pH 6.8 and 7.4. Moreover, the complex with labetalol (a less water soluble drug) presents controlled release at the three pH values studied. In this case, release is controlled by the erosion of the tablets. The results indicate that PMAOB is a good carrier for oral release of poorly soluble cationic drugs.</p>