การปลดปล่อยยาจากแคปซูลออสโมติกและปัจจัยที่เกี่ยวข้อง Drug Release from Osmotic Capsule and the Involving Factors

Abstract

AbstractConventional dosage forms normally release an active ingredient rapidlyand cannot maintain the therapeutic concentration of drug at the target sitefor a long period. To overcome this problem, scientists therefore developedan osmotic drug delivery system in a controlled-release oral dosage form.The process of drug release through a semipermeable membrane of thisform is forced by osmotic pressure which is independent from physiologicalconditions. The rate of drug release is the kind of zero order kinetics andable to be predicted accurately. Furthermore, an osmotic capsule is alsocapable to control the release of a poorly water-soluble and low osmoticpressure drug because its asymmetric membrane let a high volume ofwater fluxes in. The factor involving the rate of drug release from of thissystem includes of drug solubility, osmotic pressure in the core, surfacearea of semipermeable membrane and thickness of the capsule wall.Keywords: osmotic capsule, asymmetric membrane, release mechanism,poorly water-soluble drug