Release Characteristics And Evaluation Of Transdermal Drug Delivery System Containing Ion Exchange Fibers

Ion-exchange fibers as a new kind of drug carrier could be used for drug delivery system by the ion exchange equilibrium between drug ions and surrounding counter ions. In this paper, drug-fibers complex was prepared and added to gel, and the drug-fibers gel was harvested as a uniform system. The release studies and permeation studies of the products were carried on compared with simple gel, and the iontophoresis effects were also studied during permeation studies and the pharmacokinetics in rats which were carried out eventually for the ultimate rationality of the self-designed model.The ion-exchange fibers studied were strong anion-exchanger material (ZB-2).Several basic properties of the fibers such as true wet density, apparent wet density, specific surface, total ion-exchange capacity, pKa and inflation extent were determined as 0.28 g/ml, 0.23 g/ml, 1.40×10~4 m~2/g, 3.1 mmol/g, 8.3 and 10%～30% respepectively. Ketoprofen, KP, used as a model drug in the paper, is a nonsteroidal anti-inflammatory (NSAIDs) with analgesic and antipyretic actions. Several important parameters of KP were studied at 37℃ as follows: The solubility of KP in water, saline and pH 7.4 PBS were 176.1±7.2, 184.7±2.8 and 2871.0±103.4 μg/ml respectively and the corresponding logarithm of apparent partition coefficients using octanol as oil phase were 2.31,2.26 and 0.87 respectively. Two methods, UV spectrophotometry and HPLC, were developed for studies of ion exchange interaction or equilibrium in vitro and the studies for gel in vitro or in vivo respectively.Drug-fibers complex was prepared by bath method or column method, and it was proved that the exchange reaction between KP and fibers was not facilitated by energy. The factors affecting loading of drug were explored as follows: higher loading amount as a result of the smaller fiber size, the lower of reaction temperature and the higher concentration of KP solution for bath method; the breakthrough point was advanced by bigger fiber size, higher concentration, higher flow rate and higher reaction temperature for column method; The combination mechanism of KP-fibers was investigated by contact angle, microgram, DSC and IR spectrum method, and it...