. Author manuscript; available in PMC: 2015 Jul 15.

Published in final edited form as: Biopharm Drug Dispos. 2012 Sep 4;33(7):378–402. doi: 10.1002/bdd.1803

Table 5.

Minimum and maximum A_I/V_a values for 100 and 1000 ml hemispherical in vitro dissolution vessels

Capacity	Diameter	Minimum aqueous volume^a	Maximum aqueous volume^b	Minimum A_I/V_a^c	Maximum A_I/V_a^c
ml	cm	ml	ml	cm⁻¹	cm⁻¹
100	4	27	50	0.25	0.47
1000 (USP II)	10	288	500	0.16	0.26

Value gives minimum volume needed to achieve an aqueous liquid height high enough to allow for 1 cm below the bottom of the impeller for the 100 ml vessel (impeller is 0.8 cm tall) and 2.5 cm below the bottom of the 2 cm high impeller for the 1000 ml vessel (impeller is 2 cm tall) as well as 1 cm above the impeller for both vessels. Values calculated assuming a perfect hemispherical bottom.

Value is half of the nominal capacity of the vessel, which assumes a 1:1 ratio of aqueous to organic medium.

Minimum A_I/V_a is the aqueous-organic surface area divided by the maximum aqueous volume and maximum A_I/V_a is the aqueous-organic surface area divided by the minimum aqueous volume.