Drug-release systems, oral controlled

E. Lipka and G. L. Amidon, Setting bioequivalence requirements for drug development based on preclinical data optimizing oral drug delivery systems, J. Controlled Release, 62, 41 (1999). 

Oral controlled drug-release systems are increasingly used for short half-life drugs to reduce peak blood levels and side-eflfects, to maintain optimum drug concentration and to stimulate patient compliance. In order to maintain a constant blood-level of the drug during an extended period, a constant in vitro drug release rate is desired. The most popular controlled-release system is the matrix tablet (Desai et al., 1965). Te Wierik et al. (1996) reported on... 

Bernkop-Schnurch, A., D. Guggi, and Y. Pinter. 2004. Thiolated chitosans development and in vitro evaluation of a mucoadhesive, permeation enhancing oral drug delivery system. J Control Release 94 177. 

Hui, H. W., Lee, V. H. L., and Robinson, J. R. (1987), Design and fabrication of oral controlled release drug delivery systems, in Controlled Drug Delivery Fundamentals and Applications, Marcel Dekker, New York, pp. 373 421. 

Verma, R. K., Krishna, D. M., and Garg, S. (2002), Formulation aspects in the development of osmotically controlled oral drug delivery systems, I. Controlled Release, 79, 7-27. 

Among newly developed colon-specific drug delivery systems, pressure-controlled delivery capsules (PCDCs) [161] can be mentioned. Their mechanism of action is based on the relatively strong peristaltic waves taking place in the colon and leading to an increased luminal pressure. They consist of a capsular-shaped suppositories coated with a water-insoluble polymer (ethyl cellulose). Once taken orally, PCDCs behave like an ethyl cellulose balloon, because the suppository base liquefies at body temperature. In the upper GI tract, PCDCs are not directly subjected to the luminal pressures since sufficient fluid is present in the stomach and small intestine. The reabsorption of water in the colon provokes an increase of the luminal content viscosity. As a result, increased intestinal pressures directly affect the system via colonic peristalsis. Consequently, PCDCs mpture and drug release in the colon take place. 

Moustafine, R.I. Bukhovets, A.V. Sitenkov, A.Y. Kemenova, V.A. Rombaut, R Van den Mooter, G. Eudragit E PO as a complementary material for designing oral drug delivery systems with controlled release properties Comparative evaluation of new interpolyelectrolyte complexes with countercharged Eudragit LlOO copolymers. Mol. Pharm. 2013,10 (7), 2630-2641. 

Oral controlled release system to control the release Geomatrix Predetermined therapeutic objective for a drug SkyePharma... 

Historically, the oral route of administration has been used the most for both conventional and novel drug-delivery systems. There are many obvious reasons for this, not the least of which would include acceptance by the patient and ease of administration. The types of sustained- and controlled-release systems employed for oral administration include virtually every currently known theoretical mechanism for such application. This is because there is more flexibility in dosage design, since constraints, such as sterility and potential damage at the site of administration, axe minimized. Because of this, it is convenient to discuss the different types of dosage forms by using those developed for oral administration as initial examples. 

Controlled Release Osmotic Drug Delivery Systems for Oral Applications... 

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