Influence of storage on in-vitro release of ibuprofen from sugar coated tablets

Studies performed on ibuprofen tablets (one brand of 400 mg, two brands of 200 mg sugar coated and one brand of film coated tablets) are reported. Tab lets were subjected to conditions of 23 degreesC, 30 degreesC and 40 degree sC at 75% RH and 96% RH for periods of up to 4 weeks. Tablets were stored i n different ways-unpacked, packed in air-tight/moisture proof containers, p acked in tablet vials and packed in two unit dose packs. Dissolution was ca rried out in pH 7.2 phosphate buffer using USP or FDA conditions for ibupro fen (Basket-150 rpm or Paddle-50 rpm) with sampling and UV analysis up to 9 0 or 120 min. Serious reduction in dissolution was noted for the 400 mg sug ar coated tablets exposed to moisture. Mean % released at 30 mm (USP condit ions) was as low as 1% and, for these tablets, dissolution continued to pro ceed extremely slowly for the full dissolution period. The film coated tabl ets were not affected. The tablet vials and unit dose packs showed some pro tection. Investigation showed not only a change in the subcoat properties ( which did not break down easily) but also in the tablet core, which became hard and non-disintegrating. (C) 2001 Elsevier Science B.V. All rights rese rved.