Formulation and pharmaceutical evaluation of sulindac suspensions

Sulindac has been introduced in suspension dosage form which has suited its low aqueous solubility, its use in the fields of pediatrics and geriatrics, and its requirement of dose flexibility. A wettability study showed that 0.05% tween 20 was the wetting agent of choice. Controlled flocculation was adopted to prepare the flocculated suspensions. 32 deflocculated as well as 20 flocculated suspension formulations were prepared using different classes of suspending agents. The parameters used for evaluation were the sedimentation volume ratio [Vu/Vo], easiness of sediment redispersibility, clarity and color of supernatant, the time of the suspension has remained dispersed after being shaken, degree of flocculation, pH stability, conductivity, specific gravity, rheological properties, and dissolution. The deflocculated formula of choice was formula 18 containing 0.5% xanthan gum. The best flocculated suspension was formula 19 containing 10% glycerin, 10% propylene glycol, and 40% sorbitol as density modifiers

Further evaluation of certain sulindac suspensions

Microscopical characteristics and crystal growth, chemical stability, accelerated stability and the effect of dilution on physical and chemical stability were studied. Stable suspensions of choice were pharmacologically evaluated regarding anti-inflammatory, analgesic, and antipyretic effects as well as ulcerogenesis using laboratory animals. Clinoril tablet, the only marketed sulindac product, was taken as standard for comparison. The deflocculated formula 3 [containing 0.5% w/v xanthan gum] and the flocculated formula c [containing 10% glycerin, 10% propylene glycol, and 40% sorbitol as density modifiers] were the most stable among the tested formulae. The pharmacological evaluation of both suspension formulae showed anti-inflammatory, analgesic and antipyretic effects comparable to those of clinoril tablets; while ulcerogenesis was less. The flocculated suspension was the least ulcerogenic. Moreover, it showed earlier anti-inflammatory, analgesic, and antipyretic responses reflecting faster absorption