Design and in vitro evaluation of floating drug delivery system for an antipsychotic agent: a technical report

Floating drug delivery systems are used to target drug release in the stomach or to the upper parts of the intestine. The oral delivery of the anti-psychotic agent carbamazepine was facilitated by preparing a non-disintegrating floating dosage form which can increase its absorption in the stomach by increasing the drug's gastric residence time. The polymers used were HPMC (low and high viscosity), guar gum, and carbopol, along with sodium bicarbonate as the gas-generating agent. The prepared tablets were evaluated for their physicochemical properties and drug release. In vitro release studies indicated that the carbamazepine release from the floating dosage forms was uniform and followed a zero-order release. It was observed that the devices containing higher proportions of HPMC (high viscosity) showed slower release than those containing lower proportions while also maintaining the integrity of the device (> or = 24 h). The incorporation of guar gum helps to maintain the device's integrity, and due to its viscolysing property also affects the drug's release profile. Sodium bicarbonate which was used as the gas-generating agent causes the tablet to float for the required time (> or = 24 h).