Sustained Release Tablet Formulation for a New Iron Chelator

Sustained release tablet formulations for a new orally active iron chelator (1, 2, dimethyl-3-hydroxy-pyrid-4-one, DMHP or L1) have been developed. Coprecipitates containing DMHP and polymer were prepared and compressed into matrix-type tablets. The dissolution profiles as a function of (1) the type of polymer, and (2) polymer content, were determined. Both Eudragit types (RLPM and RSPM) and all hydroxypropylmethylcellulose (HPMC) grades (E4M, E10M, and K4M) exhibited significant sustained release activity. Above a certain ratio, increase in the polymer concentration did not provide any further decrease in the release rates. All grades of HPMC and both Eudragit RSPM and RLPM showed non-Fickian release kinetics. The role of HPMC and Eudragits in the formulation of a sustained release tablet of a water soluble drug is demonstrated.