Drugs, dissolution dialysis

Macheras, P., Koupparis, M. and Tsaprounis, C. (1986) Drug dissolution studies in milk using the automated flow injection serial dynamic dialysis technique. International Journal of Pharmaceutics, 33 (1-3), 125. 

Macheras P, Koupparis M, and Tsaprounis C. Drug Dissolution Studies in Milk using the Automated Flow-Injection Serial Dynamic Dialysis Technique. Int J Pharm 1986 33 125-136. 

Fang, Q., Sun, Y., and Fang, Z. Automated continuous monitoring of drug dissolution process using a flow injection online dialysis sampling, solvent extraction separation spectrophotometric system. Presenilis J. Anal. Chem. 364(4) 347—352,1999. 

Macheras et al.[56] used an automated FI on-line dialysis spectrophotometric system, incoiporating the dialyzer in a sample loop, to monitor the kinetic process of drug dissolution in low fat milk. The system is similar to that shown in Fig. 6.3, and the dissolution medium is circulated as donor stream through the dialyzer, pumping it from and back to the dissolution tank. Commercial formulations of salicylamide, propantheline bromide, nittbfurahtoin and acetaminophen were used in the study. The results show that the dissolution rate of drugs in milk are lower than in an aqueous buffer. 

Several methods for effective solubilization of drugs into polymer micelles have been developed (Fig. 2). The dialysis method (Fig. 2A) is most widely used for many polymeric micelle systems. The first step involves the dissolution of both polymer and drug in a water-miscible organic solvent such as acetonitrile, acetone, dimethylformamide, or ethanol. Then, the polymer-drug solution is dialyzed against water. As the organic... 

The anti-inflammatory drugs benzydamine and ketoprofen formed coprecipitates with pectin.A Langmuir-type of binding isotherm was obtained on equilibrium dialysis and this slow dissolution of the precipitate suggested that binding may help to reduce the adverse effects of these drugs to the stomach on oral administration. 

Certain food and drug regulations regard all slow-release preparations as drugs and require their safety to be established prior to clinical application. Thus, a potassium ion-selective electrode has been employed to follow [416] the release parameters of 12 encapsulated potassium chloride tablets. Several of the tablets showed only medium dissolution rates for potassium and are unlikely to cause adverse effects such as gut ulceration. A sodium electrode has been similarly used to study the release of sodium phenobarbitone through a dialysis membrane into tris buffer [417]. Sodium in organic compounds has also been determined with an Orion 94-11 sodium electrode following combustion in a closed flask [418]. 

Film casting method— This involves the dissolution of the copolymer and drug in a volatile solvent then, the solvent is evaporated, leaving the polymer film that will be used in the bottom of a vial. Afterward, a warm buffer (or water) is added under agitation to dissolve the polymer film (Burt et al. 1999 Letchford and Burt 2007). If the copolymer is not soluble in water, the literature mentions dialysis or oil in water emulsion as micelles preparation procedures ... 

---