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Z Jedras

Publications and source records attributed to Z Jedras.

10 recordsLinked to original sources
PubMed1990

Lithium acetate gastrointestinal diffusion system. Part 1: Lithium acetate single-unit gastrointestinal diffusion system: preparation and release rate studies.

The gastrointestinal diffusion system (GDS), containing lithium acetate (1), releases the drug by a controlled source of diffusion energy. The unit can possibly be used for all soluble drugs in which solubility is independent from the pH of the gastrointestinal contents as is the case with 1. The one-compartment unit is obtained by tabletting the drug and coating the tablets with a membrane of cellulose acetate to which soluble porofores-gum arabic, sodium chloride, 1-are added. When the pore-creating substance is dissolved out of the coating, there remains a porous film, which controls the rate of release of the drug. The release characteristics depend on membrane composition and mass. The systems reported here provided for zero-order drug delivery in vitro.

Acetates↗
PubMed1990

Lithium acetate gastrointestinal diffusion system. Part 2: Lithium acetate multi-unit gastrointestinal diffusion system: preparation and release rate studies.

The method of obtaining the multi-unit gastrointestinal diffusion system (m-GDS), containing lithium acetate, consists in encapsulating the lithium acetate in a form of microballs and thereafter coating the resulting microballs with a porous membrane which controls the diffusion rats of the drug. For the coating, a water-insoluble polymer (cellulose acetate) and two types of polymer-modifying agents (cetyl alcohol and shellac) were used. In this paper in vitro studies of drug release from the unit in relation to the microballs' coating and mass, and exposed surface area of the capsules are presented. Most in vitro systems provide zero-order dry delivery by appropriate selection of manufacturing parameters.

Cellulose↗
PubMed1989

Diltiazem multi-dose gastrointestinal diffusion system: preparation and release rate studies.

The present paper is concerned with a multi-dose gastrointestinal diffusion system, releasing diltiazem through a controlled source of diffusional energy. The method calls for: a) encapsulation of the drug in a microball form, and b) coating of the resulting microballs by a porous membrane which controls the diffusion rate of the drug. The system would be expected to deliver the drug at a declining rate, due to the lower solubility of diltiazem hydrochloride in the intestinal than in the stomach fluid. To maintain a constant drug diffusion rate in the intestinal fluid, a membrane-modifying agent soluble in the intestinal tract (EudragitR L.) was introduced into the cellulose acetate microball coating. In this paper in vitro studies of drug release from the unit in relation to microball coating and coating mass are presented. The system provides a zero-order drug deliver in vitro, as the result of an appropriate selection of manufacturing parameters.

Chemistry, Pharmaceutical↗
PubMed1987

In vitro study of gastrointestinal diffusion system using disopyramide phosphate.

Gastrointestinal Diffusion System (GDS) provides release of a drug by means of a controlled source of diffusion energy. The unit can possibly be used for all soluble agents in which solubility is independent of the pH of the gastrointestinal contents as is the case with disopyramide phosphate. The GDS consists of a soluble tablet-core, surrounded by a cellulose acetate film containing a soluble pore-creating agent. When the pore-creating agent is removed from the coating film, the cellulose acetate membrane which remains is of a porous nature, which controls the diffusion rate of the drug. The release rate of the drug can be varied by changing the composition and mass of the membrane. The resultant system in vitro provides the zero-order drug delivery due to the appropriate selection of manufacturing parameters.

Delayed-Action Preparations↗
PubMed1987

Gastrointestinal therapeutic system delivering of a water insoluble drug: isosorbide dinitrate (ISDN).

An oral therapeutic system can only be effective for soluble drugs. If no suitable salt of a drug can be found, then an osmotic agent such as sodium chloride or mannitol has to be used in a modified two-chamber system, or the osmotic dispenser with collapsible supply container. A one-chamber gastrointestinal therapeutic system (GTS) is proposed which is capable of delivering insoluble drug at a relatively constant rate. The unit consists of a tablet containing the insoluble drug and the soluble carrier, surrounded by a rate-controlling membrane with a delivery orifice. If the unit is in contact with fluid, water will pass constantly through the membrane into the tablet, dissolve the carrier which will be pumping out the insoluble drug through the delivery orifice. The effect was studied of variable content and weight of the tablet, size of the delivery orifice and thickness of the membrane on the rate of insoluble drug release from the GTS.

Excipients↗