Drug delivery systems hydrogels

EH Schacht. Hydrogel drug delivery systems physical and ionogenic drug carriers. In JM Anderson, SW Kim, eds. Recent Advances in Drug Delivery Systems. New York Plenum Press, 1984, pp 259-278. 

Hydrogel drug delivery systems can be used in the hydrated state (as in Figure 9.17) or dried before use. Dried hydrogels absorb water from the exter-... 

Biodegradable Polymers Used in Preparation of Hydrogel Drug Delivery Systems and Their Application... 

R. Oun, J.A. Plumb, and N.J. Wheate, A cisplatin slow-release hydrogel drug delivery system based on a formulation of the macrocycle cucurbituril, gelatin and polyvinyl alcohol, /. Inorg. Biochem., 134,100-105,2014. 

Polyphosphazenes can be considered as biomaterials in several different ways, depending on the type of utilization one can predict for these substrates. In this regard, we will consider three different topics concerning water-soluble POPs and their hydrogels, bioerodible POPs for drug delivery systems and for tissue engineering, and the surface implications of POP films. 

Poly[(4-carboxylatophenoxy)(methoxyethoxyethoxy)phosphazene] copolymers of variable compositions were synthesized by Allcock [645] in 1996. These polymers were found to be soluble in alkaline solutions. When crosslinked (by y-rays or by addition of CaCl2 to the polymer solution) the resulting hydrogels were found able to contract or expand as a function of the pH of the solution and their utilization as pH-responsive materials for drug delivery systems could be envisaged. 

In summary, the advantages of our approach to studying gastric retention are twofold. First, hydrogel response to the gastric environment can be noninvasively visualized in real-time. Second, a more efficient and justifiable approach to the development of long-term oral drug delivery systems can be achieved. 

SH Gehrke, PI Lee. Hydrogels for drug delivery. In P Tyle, ed. Specialized Drug Delivery Systems, Manufacturing and Production Technology. New York Marcel Dekker, 1990, pp 333-392. 

In the gastrointestinal tract, a mucoadhesive drug delivery system provides advantages in prolonging the residence time of devices. The use of pH-sensitive bioadhesive polymers has been proposed [26], An extensive review of pH-sensi-tive hydrogels is given by Brpndsted and Kopecek [27],... 

Schiraldi et al. [64] have developed this kind of material by combining silica particles and pHEMA. pHEMA is a biocompatible hydrogel that has been widely studied in the past decades due to its chemical-physical structure and mechanical properties. It has been widely used in ophthalmic prostheses (contact or intraocular lenses), vascular prostheses, drug delivery systems and soft-tissue replacement [65]. These authors have shown that by incorporating silica nanoparticles, the resulting hybrid material is highly biocompatible and promotes bone cell adhesion and proliferation of bone cells seeded on it.1 ... 

Nabeshima, Y., Ding, Z. L., Chen, G. H., Hoffman, A. S., Taira, H., Kataoka, K., and Tsuruta, T., Slow release of heparin from a hydrogel made from polyamine chains to a temperature-sensitive polymer backbone, in Advanced Biomaterials in Biomedical Engineering and Drug Delivery Systems (N. Ogata, et al., Eds.), pp. 315-316. Springer, Tokyo (1996). 

Wu J, Wei W, Wang LY, Su ZG, Ma GH (2007) A thermosensitive hydrogel based on quatemized chitosan and polyethylene glycol) for nasal drug delivery system. Biomaterials 28 2220-2232. 

Chiu, H.C., Hsiue, G.H., Lee, Y.P., and Huang, L.W., Synthesis and characterization of pH-sensitive dextran hydrogels as a potential colon-specific drug delivery system, J. Biomater. Sci. Polym. ed., 10 591-608 (1999). 

Noninvasive drug delivery may require the administration of the drug delivery system (DDS) at an epithelium as a suitable site of absorption of the active compormd. Such regions are usually called mucosae. In the human body several mucosal sites can be identified, the one mostly used for administration and absorption of therapeutics being the gastrointestinal route. In order to increase the residence time at these absorption sites, a so-called mucoadhesive delivery system has to be used. Generally, these systems consist of one or more types of hydrogels. 

The eoneept of mueoadhesion in drug delivery was introduced in the field of controlled-release drug delivery systems in the early 1980s [2,3]. Thereafter, several researchers have focused on the investigations of the interfacial phenomena of mucoadhesive hydrogels (and of other type mucoadhesive compounds) with the mucus. Several techniques of studying these interactions were evaluated both in vitro and... 

A mueoadhesive hydrogel used as a drug delivery system should... 

Caramella, C M., Rossi, S., and Bonferoni, M.C., A Rheological Approach to Explain the Mucoadhesive Behavior of Polymer Hydrogels. In Bioadhesive Drug Delivery Systems (E. Mathiowitz, D.E. Chickering, III, and C.-M. Lehr, eds.), Marcel Dekker, Inc., New York, 1999, pp. 25-65. 

Applications of hydrogels include highly absorbent diapers based on poly(sodium acrylate), contact lenses based on poly(2-hydroxyethyl methacrylate) (polyHEMA), and switches based on variations of swelling of the hydrogels. A number of drug delivery systems have also been based on hydrogels. 

Elvira, C., Mano, J. F., San Roman, J., Reis, R. L. (2002). Starch-based biodegradable hydrogels with potential biomedical applications as drug delivery systems. Biomaterials, 23(9), 1955-1966. 

Contact lenses - [CONTACT LENSES] (Vol 7) -disinfectant for [CITLORINE OXYGEN ACIDS AND SALTS - CH.OROUS ACID, CH.ORITES, AND CHLORINE DIOXIDE] (Vol 5) -disinfectants for [DISINFECTANTS AND ANTISEPTICS] (Vol 8) -methacrylates m [METHACRYLIC POLYMERS] (Vol 16) -PVP hydrogels [VINYL POLYMERS - N-VINYLAMIDE POLYMERS] (Vol 24) -sterilization usingH202 [HYDROGEN PEROXIDE] (Vol 13) -use m drug delivery [DRUG DELIVERY SYSTEMS] (Vol 8)... 

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