Use of cassava starch nanocrystals to make a robust rupturable pulsatile release pellet

Abstract

This study aimed to investigate cassava starch nanocrystals as a filler in rupturable ethylcellulose film to fabricate a more robust system for pulsatile delivery. The rupturable pulsatile release pellets consisting of a drug (theophylline) layered core, a swelling layer (croscarmellose sodium) and a rupturable layer of ethylcellulose with cassava starch nanocrystals were developed. The effects of amount of cassava starch nanocrystals, coating levels of swellable and rupturable layers on lag time and drug release were investigated. The results revealed that cassava starch nanocrystal decreased puncture strength and elongation at break of ethylcellulose film. Lag time of the pulsatile pellets was increased with increasing levels of swellable and rupturable coatings, whereas increasing amount of cassava starch nanocrystals decreased lag time and lowered sensitivity of lag time on the rupturable coating level. Additionally, increasing level of swellable layer and amount of cassava starch nanocrystals led to rapid drug release after lag time whereas higher level of rupturable layer caused a slower drug release. In conclusion, cassava starch nanocrystals could lower the mechanical properties of the ethylcellulose film and lower sensitivity of lag time on the rupturable coating level, providing the robust pulsatile release system with rapid drug release after lag time.