بررسی تاثیر پلیمرهای اودراجیت و HPMC با استفاده از روش مایع به جامد بر کنترل رهش تئوفیلین

Abstract Background and purpose: Recent researches have shown that liquisolid technique is a new and promising method for controlling the dissolution rate of drugs. In this study the effects of Eudragit RS PO and HPMC on theophylline release from liquisolid compacts were evaluated. Materials and methods: Theophylline was dispersed in PEG 200 as the liquid vehicle. Then a binary mixture of carrier coating materials (Eudragit or HPMC as the carrier and silica as coating material with 2:1 ratio) was added to the liquid medication under continuous mixing in a mortar for 10 minutes. The mixture was compressed using the manual tableting machine. After preparing several formulations the release profiles were evaluated. To evaluate any interaction between theophylline and the other components in liquisolid formulations the differential scanning calorimetery (DSC) and FTIR were used. Results: Theophylline tablets prepared by liquisolid technique and contained Eudragit RS PO showed greater retardation properties in comparison with conventional matrix tablets. This investigation provided evidence that PEG 200 has important role in sustaining the release of drug from liquisolid. The kinetic studies revealed that in liquisolid formulations, release kinetic was changed in evaluated formulations containing several polymers. DSC and FTIR showed no complexation between drug and polymer and no change in drug polymorphism. Conclusion: The results showed significant effect of liquisolid technique on the theophylin release rate from related liquisolid systems.