Monolithic drug delivery systems

Figure 7 A schematic of a monolithic drug delivery system. (From Ref. 109.)...

Monolayer blown-film extrusion, VDC copolymers in, 25 725, 728-729 Monolayers, self-assembled, 77 57 Monolayer self-assembled systems, 16 800 Monolignols, 27 10—11, 13, 14 Monolithic drug delivery systems, 9 11 Monomagnesium phosphate, 78 839 Monomer addition, in PVC polymerization, 25 665-666... 

Transbuccal drug delivery systems are a new technology and spinoff of transdermal/topical drug delivery systems. Similar to monolithic adhesive matrix—type skin patches, transbuccal systems are designed to adhere to mucosal tissue in the oral cavity. A number of compounds are being evaluated in clinical studies.88... 

Because of the large surface area of the skin and its bypass of the liver as a first pass step in metabolism, many drug delivery systems have been developed that control the rate of drug delivery to the skin for subsequent absorption. Effective transdermal drug delivery systems of this type deliver uniform quantities of drug to the skin over a period of time. Technically, transdermal drug delivery systems may be classified into monolithic and membrane-controlled systems (9). 

Fig. 26 Cross-sectional view of a bioerosion-regulated hydrocortisone delivery system, a feedback-regulated drug delivery system, showing the drug-dispersed monolithic bioerodible polymer matrix with surface-immobilized ureases. The mechanism of release and time course for the urea-activated release of hydrocortisone are also shown. (From Ref > 1)...

Figure 2.8 Schematic of a monolithic transdermal drug-delivery system (A) and the drug-release rate obtained (B).

S.B. Tiwari, and A.R. Siahboomi, Extended-release oral drug delivery technologies Monolithic matrix systems, in KK. Jain, ed.. Drug Delivery Systems, Humana Press, Totowa, NJ, 217-243, 2004. 

Transdermal drug-delivery systems offer several important adventages over more traditional approaches, in addition to the benefits of avoiding the hepatic first-pass effect. Transdermal drug delivery systems (TDDS) are usually in the form of patches incorporating pressure sensitive adhesives. There are two basic designs for transdermal patches matrix or reservoir type. Matrix-type patches include monolithic adhesive and polymer matrices, whereas reservoir-type patches include liquid and solid-state reservoirs [71-73]. For various types of transdermal delivery systems, medical grade adhesive silicones are used as [73,74] ... 

Adhesive patches may also be monolithic or multilayered devices of the reservoir or matrix type for either systemic or local drug delivery (Fig. 8). The two main manufacturing processes to prepare adhesive patches are solvent casting and direct milling (with or without a solvent). The intermediate product is a sheet from which... 

Hite, M., Federici, C., Turner, S., and Fassihi, R. Novel design of a self-correcting monolithic controlled-release delivery system for tramadol. Drug Del. Tech. 3 48-55, 2003. 

Extended-Release Oral Drug Delivery Technologies Monolithic Matrix Systems... 

Morphology control is indispensable in many of the advanced applications envisioned for functional mesoporous materials (54, 267). Permselective membranes, micro-spheres, or monoliths are important for sorption, separation, and chromatography purposes. Porous thin films or fibrous structures are relevant for electronics, optics, low fe-dielectrics, and sensing applications. Colloidal particles or nanospheres are preferred for biomedical systems to be used in drug delivery or magnetic resonance imaging (MRl) with contrast agents. 

The polymer will play a passive role if it acts solely as a barrier which controls the rate of drug delivery by diffusion. Indeed, changes in the properties of the polymer are undesirable in this case since thereby the parameters governing the diffusion process will change. Purely diffusion controlled delivery systems generally belong to either one of two types, monolithic devices or reservoir devices. 

The authors manufactured a monolithic device made of a NIPAAm-BMA copolymer gel with a film thickness of 0.5 mm and a diameter of 15 mm in which the nonsteroidal drug, indomethacin, was used as the model drug. The drug delivery behavior of this system was measured. After the initial delivery, 0th delivery was observed (Fig. 7(a)). The delivery rate accel-... 

---