The formulation of sustained release tablets of AMD-HCl using KOLLIDON SR as matrix-forming agent. Chitosan, a natural polysaccharide with superior hydrating and absorbing properties was used in the formulation stage to optimize the release characteristics of those matrix tablets. Nine formulations of sustained release matrix tablets of AMD x HCl (200 mg/tablet) were prepared through direct compression. The concentrations of matrix forming agents were included as independent variables of a type 2(3) mixed factorial plan in order to develop formulations of AMD-HCl with optimal release characteristics. The dependent variables of that plan were the amount of AMD released from the tablets studied by using in vitro dissolution testing. The test was carried out in the paddle apparatus II for 12 hours in two pH media that were relevant to oral delivery: 2 hours at pH 1.2 and 10 hours at pH 6.8. The released AMD-HCl was quantitatively determined through a validated HPLC method. The increase in KOL concentration leads to a decrease in AMD release rate at both pH values. The use of CHT resulted in a decrease of AMD release only at pH 6.8 in formulations with the lowest concentration of KOL. The retarding effect on the release of AMD-HCl in the tablets developed in this study was directly proportional to the KOL concentration in the formulation.