بررسی تأثیر اعمال حرارت بر کنترل سرعت آزادسازی تئوفیلین از ماتریس‌های حاوی پلیمرهای اودراجیت RS و M4K HPMC با استفاده از روش مایع به جامد

Background and purpose: The potential of liquisolid systems for increasing drug dissolution has been proved in many researches. Recent studies have shown that liquisolid technique is a new and promising method for controlling the dissolution rate of drugs. Based on thermal treating effect on polymer structure, in this study the effects of thermal treating on theophylline release from liquisolid compacts containing Eudragit RS PO and HPMC (hydroxypropyl methylcellulose) 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, and then treated in 50, 60, and 70 0C for several periods of times. The release profiles were evaluated. The differential scanning calorimetery (DSC) and fourier transform infrared (FTIR) were used to evaluate any interaction between theophylline and the other components in liquisolid formulations. Results: Thermal treating showed significant decrease in drug release from Eudragit RS containing liquisolid systems. The thermal treating time showed significant effect on theophylline release. This was not observed in liquisolid tablets containing HPMC. DSC and FTIR showed no complexation between drug and polymer and no change in drug polymorphism. Conclusion: The liquisolid technique could be used for design controlled release systems. Thermal treating could affect drug release by affect on polymer structure