title: A programmable drug delivery system for oral administration.
abstract: A programmable, controlled release drug delivery system has been developed. The device in the form of a non-digestible oral capsule (containing drug in a slowly eroding matrix for controlled release) was designed to utilize an automatically operated geometric obstruction that keeps the device floating in the stomach and prevents it from passing through the remainder of the GIT. Different viscosity grades of hydroxypropyl-methyl-cellulose were employed as model eroding matrices. The duration during which the device could maintain its geometric obstruction (caused by a built-in triggering ballooning system) was dependent on the erosion rates of the incorporated polymers (the capsule in-hosed core matrix). After complete core matrix erosion, the ballooning system is automatically flattened off so that the device retains its normal capsule size to be eliminated by passing through the GIT. In vitro long-term drug delivery from a prototype model was studied using levonorgestril as a model drug. Zero-order release could be maintained for periods ranging between 5 and 20 days before the geometric obstruction is triggered off. The rate of drug release was dependent on the nature, viscosity and ratios of polymer employed.
authors.affiliation: Department of Pharmaceutics, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt.
authors.forename: F M
authors.initials: FM
authors.lastname: Sakr
mesh_terms: D000284:Administration, Oral; D002626:Chemistry, Pharmaceutical / Q000379:methods; D003692:Delayed-Action Preparations; D016503:Drug Delivery Systems; D065347:Hypromellose Derivatives; D007408:Intestinal Absorption; D016912:Levonorgestrel / Q000008:administration & dosage; D008747:Methylcellulose / Q000031:analogs & derivatives / Q000737:chemistry; D045167:Progesterone Congeners / Q000008:administration & dosage; D014783:Viscosity
chemical_list: D003692:Delayed-Action Preparations; D045167:Progesterone Congeners; D065347:Hypromellose Derivatives; D016912:Levonorgestrel; D008747:Methylcellulose