Study On Sodium Polystyrene Sulfonate Drug-resins Liquid Sustained-release System

Oral sustained-release suspension was a novel liquid prolonged-release dosage form which was a two-phase system composed of sustained-release drug microparticles and suspending medium. As a multi-units system, it presented several advantages such as steady release rate,little stomach-empty effect, easiness to divide. In this article pharmaceutical grade expicients sodium polystyrene sulfonate-ion exchange resin was self made, and then Metformin Hydrochloride(MH),Ambroxol Hydrochloride(AH), Acyclovir(ACV) were used as model drug to make the resinates. After that the spray fluidized coat method and the emulsion-solvent difiusion method were adopted to prepare the three drug-resinates sustained microcapsules. Besides the pharmacokinetics study of the three sustained-release suspensions in beagle dogs were carried out. After the study on the general ion exchange resin, A novel pH-sensitive ion exchange resin was synthesized to prepare a novel pulsatile dosage form. Research work was composed of the following parts:1. The sodium polystyrene sulfonate-ion exchange resin was synthesized by the suspension polymerization and the sulfonation reaction. The properties of the prepared ion exchange resins and resinates had been characterized by FTIR,DSC,X-ray .The results showed that the obtained ion exchange resin was polyelectrolyte microspheres with the particle diameter in the range of 60 ～ 200 μm, and the drug combined with the resins by the chemical bond. Also this article assessed the quality of sodium polystyrene sulfonate including the foreign sample, the domestic sample and the synthesized sample in lab according to the methods and the standards which are provided in USP, BP and CP. The following items were examined: particle size, water content, sodium content, potassium exchange capacity, the residual 1, 2- dichloroethane, the reaction characteristic of sodium salts and limit of ammonium salts and heavy metals. The results indicated that the domestic sample could not be used as a pharmaceutical grade expicient, while the foreign sample and the synthesized sample in lab could be applied as pharmaceutical grade expicient.2. In the preformulation research, the analysis methods for dissolution and contents tests for MH,AH,ACV drug-resinate(microencapsulation), Salbutamol Sulfate drug-resinates were established. The solubility determination results revealed that MH was easy to dissolve; AH could dissolve, and ACV was difficult to dissoluble in water.