Design and characterization of intra-oral fast dissolving tablets containing diacerein-solid dispersion

ABSTRACT

Diacerein (Diacetylrhein, DCN) is anthraquinone derivatives used in the curing of osteoarthritis, but its usage isrestricted due to its very poor solubility and wettability which result in bioavailability variation. The objective ofthis work was to design fast dissolving tablets (FDTs) of DCN solid dispersion. Solid dispersions (SDs) and physicalmixtures (PMs) were prepared with PEG4000, Polyvinylpyrolidone K25 (PVPK25), and Sorbitol. SD formationincreased the dissolution rate of DCN compared to PM; this demonstrates that the improvement of dissolution ratewith SD can be due to physical change in drug crystal which was confirmed by thermal analysis. SD with Sorbitol wasselected for the preparations of FDTs. Seven formulations were prepared by direct compression method using differentconcentrations of crospovidone (CP) as superdisintegrant and camphor as subliming agent. Pre- and post-compressionevaluation were carried for powder blend and the prepared FDTs, respectively. F7 (composed of 120 mg CP, 45 mgcamphor, 200 mg SD containing 50 mg DCN, 7.5 mg aspartame, 2.5 mg menthol, 2.5 mg Magnesium stearate, and22.5 mg lactose) showed the shortest disintegration time and the highest dissolution rate and it was selected for furtherinvestigation. Kinetic studies of the in vitro release results showed that F7 followed first-order kinetics. Stabilitystudies conducted for formula F7 showed good stability upon storage at 30oC/75% RH and 40oC/75% RH for 12 weeks.