Background: 6-MP has short elimination time (<2 h) and low bioavailability (~ 50%). Present
study was aimed to develop time controlled and site targeted delivery of 6-Mercaptopurine
(6-MP) for treatment of colon diseases.
Methods: Compression coating technique was used. 32 full factorial design was designed for optimization
of the outer coat for the core tablet. For outer coat amount of Eudragit RS 100 and hydroxypropyl
methylcellulose (HPMC K100) were employed as independent variables each at three levels while responses
evaluated were swelling index and bursting time. Direct compression method was used for
Results: 80% w/w of microcrystalline cellulose and 20% w/w of croscarmellose sodium were found to be optimum concentration
for the core tablet. The outer coat of optimized batch (ED) contains 21.05% w/w Eudragit RS 100 and 78.95%
w/w HPMC K100 of total polymer weight. In-vitro dissolution study indicated that combination of polymer retards the
drug release in gastric region and releases ≥95% of drug in colonic region after ≥7 h. Whereas in case of
in-vivo placebo x-ray imaging study had shown that the tablet reaches colonic part after 5±0.5 h providing the proof of arrival
in the colon. Stability study indicated that the optimized formulation were physically and chemically stable.
Conclusion: Present research work concluded that compression coating by Eudragit RS 100 and HPMC K100 to 6-MP
core provides potential colon targeted system with advantages of reduced gastric exposure and enhanced bioavailability.
Formulation can be considered as potential and promising candidate for the treatment of colon diseases..