In vitro conditions for the study of the in vivo performance of sustained release theophylline matrix tablets administered in fasted conditions and with a high-fat diet

Dissolution profiles of theophylline (TP) from three types of sustained-rel ease (SR) matrix tablets (plastic [PL], lipid [LP], and hydrophilic [HP]) i n different dissolution media, with and without enzymes, were established A lso investigated was the influence of a treatment of the tablets with peanu t oil prior to the dissolution test. The in vivo behavior of the tablets un der the fasted state and with the concomitant administration with a high-fa t diet was previously evaluated; the diet produced changes in the absorptio n profiles for the three matrix tablets in comparison with fasted administr ation. Level A correlations were obtained between cumulative percentage dis solved (CPD) and cumulative percentage absorbed (CPA). For the fasted condi tion, better correlations were obtained with water as the dissolution mediu m for the HP and LP matrix; for PL matrix, the best correlation was obtaine d with a medium with gradual change of pH. The pretreatment with peanut oil showed better correlations for the fed state.