Considerations in Choosing a Deaeration Technique for Dissolution Media

Introduction D issolution results for some phannaceutic-al dosage fonns may be affected by dissolved air in the djssolution medium. This effect can be elimi nated by effective deaeratioll of the dissolution mediu m. Parameters chosen to judge the effectiveness of deaeration have typica ll y been dissolved oxygen content and results from ca~brator tablets. A dis· solution calibratio n method known to be sensitive to deaeration , the NCDA #2 tablet method, (5) was chosen to determi ne efficacy of deaeration. The USP ca librator tablet method was not chosen because of known insensitivity to deaeration using prednisone tablets at 50 rpm with Apparatus 2(6). Other parameters involved in the selection of a deaeration method arc case of use and expense. For the eva luation of the different deaeration techniques, the USP method was chosen as the benchmark (2). The effec­ tiveness of the dearation techniques was eva luated by measuring the amount of dissolved oxygen in the deaerated disso lution media and eva luating the results from the dissolu­ tion of the NCDA #2 test performance tablets. Experimental I. A YSr model 5004 Dissolved Oxygen Meter was used to measure the (~Ived oxy· gen content of the deaerated disso lution media. The instrument was calibrated daily according to the manuFacrurer's directions. 2. The method and specifi·