Drug-polymer complex

The release kinetics from the tablets of the drug-polymer complexes were carried out in buffered release media containing 0.01 M phosphate and NaCl ranging from 0.2 M to 0.02 M at 37°C by the USP basket method at 100 rpm. Drug release was monitored on a HP 8452A diode-array spectrophotometer at 250, 306, 306, 270, 278, 278, and 274 nm for sodium diclofenac and sulfathiazole, labetalol HCl, propranolol HCl, verapamil HCl, and diltiazem HCl, respectively. 

Polymer-based [ethylidene-2,4,8,10-tetraoxaspirol(5,5)undecane Bioerosion of drug polymer complex Insulin pH change ... 

Figure 7 Effect of polymer composition on the release of labetalol from drug-polyelectrolyte complex tablets at pH 7.0 (0.2 M NaCl). 

Kitano, S., Koyama, Y., Kataoka, K., et al. A novel drug delivery system utilizing a glucose responsive polymer complex between poly (vinyl alcohol) and poly( V-vinyl-2-pyrrolidone) with a phenylboronic acid moiety. J. Contr. Rel. 19 161—170, 1992. 

Mass spectra are used to determine molecular weights and molecular composition (from the parent or molecular ion) and to obtain structural information from the fragmentation of the molecular ion into daughter ions. Electrospray ionization (ESI-MS) and matrix-assisted laser desorption ionization (MALDI-MS) mass spectroscopy can be used to obtain structural information about macromolecules, including proteins, polymers, and drug-DNA complexes. 

Kim C-J, Nujoma YE (1995) Drug release from an erodible drug-polyelectrolyte complex. Europ Polymer J 31 937-940... 

Controlled-release polymer implants are useful for delivering drugs directly to the brain interstitium. This approach may improve the therapy of brain tumors or other neurologieal disorders. The mathematical models described in this section—which are based on methods of analysis developed in earlier chapters—provide a useful framework for analyzing mechanisms of drug distribution after delivery. These models describe the behavior of chemotherapy compounds very well and allow prediction of the effect of changing properties of the implant or the drug. More complex models are needed to describe the behavior of macromolecules, which encounter multiple modes of elimination and metabolism and are subject to the effects of fluid flow. 

An attempt to improve the defect has been made by the addition of HPC or polyvinylpyrrolidone (PVP) which removed the defect of diazepam (Fig. 14.12). Likewise, Loftsson et al. have reported the enhancement of oral drug bioavailability as a result of the combined action of CyD complexation and water-soluble polymers such as HPC or PVP. The enhancement is caused by an increase in the apparent stability constant of the drug/CyD complexes via the formation of ternary drug/CyD/polymer complexes [83]. 

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