A new gastroretentive dosage form: floating dome Matrix®

ALVARO FEDERICO JIMENEZ KAIRUZ; RUGGERO BETTINI,; SONVICO, F.; PAOLO COLOMBO,

Nashville, TN

Congreso; 2005 American Association of Pharmaceutical Scientists: Annual Meeting and Exposition; 2005

Purpose.Hydrophilic matrices prepared by direct compression, shaped as disc having concave and convex bases, were used as drug delivery modules in controlled release system (Dome Matrix® technology). When two modules were soldered with the concave bases facing each other, a void space inside the system was created resulting in a floating device (void configuration). An alternative assemblage was obtained by soldering two modules with the convex base inserted in the concave base (stacked configuration) from modules and systems. Ribofavin was used as model drug for studying release kinetics.Methods.Five series of modules were prepared using two HPMC K15M and K100LV, in these proportion: 100:0, 75:25, 50:50, 25:75 and 0:100 (total HPMC 40%, riboflavin 4%, lactose 45.8%, PVP 5%, PEG6000 5% and Mg stearate 0.2%). Modules were soldered using a Branson ultrasound apparatus. In vitro release studies were performed using a USPXXVI dissolution apparatus 2, with 900ml of simulated gastric fluid at 37°C.Results.The release rate of riboflavin from single module could be modified varying the two HPMC proportions: mean dissolution time (MDT) change between 496 and 163min. The matrices containing the mixture 50:50 of the two HPMC were selected to prepare the floating and stacked systems. The release profiles obtained with the individual modules and the two were linear inthe first 60% of release. The MDT calculated were 333, 375 and 447min for the module, the floating system and the staked configuration, respectively. The floating system remained soldered and floated for at least than 4 hours.Conclusion.The assemblage of two modules produced a change in the release rate of riboflavin without change the kinetics. The assembled modules in void configuration were able to float immediately and for a prolonged time, assuring a time and space drug control release.