Aim: The study was carried out with the objective of comparing the release retardant effect of some novel lipids by preparing sustained release tablets of highly water- soluble drug, theophylline. Methods: The tablets were a mixture of theophylline and each of the three novel lipids taken in different ratios (Compritol ATO 888, Precirol ATO 5, Dynasan 114) prepared by Direct compression method. Drug and novel lipids interaction was determined by FTIR spectroscopy and DSC while drug release from the sustained release tablets was studied using USP-ll dissolution apparatus. The release was analysed to determine the lipid showing the best retardant effect. It was also subjected to different kinetic models to evaluate the release kinetics and mechanism of release. Statistical analysis was done on in-vitro release data by ordinary one-way ANOVA to check for significant difference in release for different formulation. The hardness and other evaluation parameters of the tablets were within acceptable range. Results: FTIR and DSC showed no interaction between the drug and the lipids of the formulations (DC1 to DC9) and DC1 formulation showed the best sustained release in 12 hr. The result of release retardant effect given by the lipids is in the order dynasan < precirol < compritol. Conclusion: The study showed that Compritol ATO 888 (glyceryl behenate) was highly hydrophobic lipid and therefore showed best sustained release of water-soluble drug theophylline as compared to Precirol ATO 5 (glyceryl palmitostearate) and Dynasan 114 (glyceryl tri myristate) lipids.
Key words: Theophylline, Direct Compression, Sustained Release, Compritol ATO 888, Precirol ATO 5, Dynasan 114.