A collaborative study of the in vitro dissolution of acetylsalicylic acid gastro-resistant capsules comparing the flow-through cell method with the USP paddle method

A collaborative in vitro dissolution study was performed comparing the Flow-through cell (FTC) method with the USP Paddle method. The objective was to compare the two methods regarding their suitability for changing the pH of a dissolution medium and for measuring the in vitro dissolution of a gastro-resistant dosage form. Aspirin, a gastro-irritant substance in an enteric-coated, multiple-unit dosage form, was used as the test material. The results show that the FTC method gives comparable results compared with the Paddle method. The FTC method is also more convenient to use for shifting the pH from an acidic condition at pH 1.2 to a pH of 6.8. The effect of different ionic strengths of the dissolution media on dissolution rate results was observed for the test product by using the FTC method. (C) 1997 Elsevier Science B.V.