Controlled-release drag delivery systems

There are a host of other, non-catalytic applications of TUD-1 possible, for example in the area of sorption. In fact, the successful application of TUD-1 as a controlled release drag delivery system was recently demonstrated (33). 

Deshpande, A. A., Rhodes, C. T., Shah, N. H., and Mallick, A. W. (1996), Controlled-release drag delivery systems for prolonged gastric residence An overview, Drug Dev. Ind. Pharm., 22, 531-539. 

Bridges JF, Woodley JF, Duncan R, et al. Soluble N-(2-hydroxypropyl) methacrylamide copolymers as a potential oral, controlled-release, drag delivery system. I. Bioadhesion to the rat intestine in vitro. Int J Pharm 1988 44 213-223. 

Sustained and Controlled Release Drag Delivery Systems, edited by Joseph... 

Reservoir-Based MEMS Drug Delivery System, Fig. 1 Dmg conccaitration as a function of time. Singledose profile depicts a typical dmg concentration profile using eonventional dmg delivery routes. Controlled-release profiles depict the dmg concentration profile fiom a etmtrolled-release drag delivery system... 

Compounds that show low but intrinsic absorption can be optimized by various galenic techniques and procedures. However, those which possess no absorption ability at all cannot be optimized by such procedures. New strategies have been developed for novel drag delivery systems to control drag release, transport, and absorption across mucosal membranes. A special class of modifiers are amphiphilic... 

A wide variety of drag delivery systems have been developed to achieve zero-order controlled release and are discussed further in the relevant chapters. 

Since the dissolution of polymeric materials is the key to this mechanism, the polymers used must be water-soluble and/or degradable in water. The choice of a particular polymer for a particular controlled release dosage form depends on various factors such as the dissolution mechanism, delivery period, delivery route, the drag etc. In general, synthetic water-soluble polymers tend to be widely used for oral-controlled release dosage forms. Biodegradable polymers tend to be used for injectable, or implantable, drag delivery systems. 

Although available in a wide variety of shapes, sizes and mechanisms of rate-controlled release, desirable attributes of all drag delivery systems include ... 

A number of novel drag delivery systems have been identified as potential systems for controlling drag-release within the lung and include ... 

The integration of biosensors with drag delivery systems allows the controlled release of a drag substance in response to the levels of biological modulator. For example, the use of a glucose biosensor may be used to control the release of insulin from an implanted device or perhaps even an iontophoretic delivery device (see Chapter 8). 

Diffusion is one of the basic mass transport mechanisms, which is involved in the control of drag release from numerous drag delivery systems (14-16). Pick was the first to treat this phenomenon in a quantitative way (21), and the textbook of Crank (22) provides various solutions of Pick s second law for different device geometries and initial and boundary conditions. A very interesting introduction into this type of mass transport is given by Cussler (23). 

Coutts-Lendon CA, Wright NA, Mieso EV, et al. The use of FT-IR imaging as an analytical tool for the characterization of drag delivery systems. J Control Release 2003 93(3) 223-248. 

Kitano, S., Koyama, Y., Kataoka, K., Okano, T., and Sakurai, Y., 1992, A novel drag delivery system utilizing a glucose responsive polymer complex between poly(vinyl alcohol) and poly(iV-vmyl-2-pyrrolidone) with a phenylboronic acid moiety, J. Controlled Release... 

MicrocrystalUne cellulose (MCC) is mainly used in the pharmaceutical industry as a diluent/binder in tablets for both granulation and direct compression processes. Treating high quality cellulose with hydrochloric acid to the desired level yields purified miCTocrystalline cellulose which is a partially depolymerized cellulose [21]. Membrane controlled systans or monolithic matrix drag delivery systems obtained from cellulose derivatives provide controlled release of drags. Film coating techniques are employed for the manufacture of membrane controlled... 

Jin, Q., Mitschang, F., Agarwal, S. Biocompatible drag delivery system for photo-triggered controlled release of 5-lluorouracil. Biomacromolecules 12,3684-3691 (2011)... 

Chitosan microspheres have potential application in dmg delivery systems because they can be used to enable the controlled release of many drags and to improve the bioavailability of degradable substances or to enhance membrane permeability. The role of chitosan microspheres as a drag delivery system has been widely studied in a variety of drags, such as proteins, peptides, and vaccines [41, 57, 58,69, 178, 182],... 

It is estimated that 90% of all medicines usage is in oral forms and oral products consistently comprise more than half the annual drag delivery market. It is the preferred route of administration, being convenient, controlled by the patient and needs no skilled medical intervention. Considerable success has been achieved with various types of controlled-release systems for peroral delivery, which are used to prolong drag effects. 

Tracheobronchial deposition of such carriers may not be desirable as clearance on the mucociliary escalator will occur in a relatively short time providing insufficient time for release from these controlled-release systems. Alveolar deposition will, in contrast, result in extended clearance times which are dependent on the nature of the carrier particle and may therefore be a better option for the effective use of such carrier systems for pulmonary drag delivery. 

The rate of liposome accumulation in alveolar type-II cells is dependent on lipid composition. It is therefore possible to select liposome compositions displaying minimal interaction with these cells and thereby function as controlled-release systems for entrapped solutes. For example, liposomes composed of dipalmitoylphosphatidylcholine and cholesterol and containing entrapped sodium cromoglycate will provide sustained delivery of the drag for over 24 hours. Conversely other liposome compositions could be utilized for enhanced epithelial interaction and transport of the drug (e g. cationic lipids for the cellular delivery of the CFTR gene). 

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