In diffusion cell testing, the active pharmaceutical ingredient (API) passes from the dosage chamber into the receptor medium in an amount proportional to the exposed area of the membrane, as determined by the orifice diameter. Phoenix cell cap kits are designed to provide analysts with precise control over this critical factor. In each cell cap kit, the orifices of the dosage chamber above the membrane and the cell cap below the membrane are machined to tight tolerances for diameter and concentricity.

Threaded Caps

Cell Size	Orifice Diameter (mm)	Membrane Exposed Area (mm2)	Dosage Chamber Height (mm)	Maximum Dosage Volume (mL)	O-Ring Material
Small	9	64	13	0.8	Viton
	9	64	13	0.8	Kalrez
	11.3	100	13	1.3	Viton
	11.3	100	13	1.3	Kalrez
Medium	11.3	100	13	1.3	Viton
	11.3	100	13	1.3	Kalrez
	15	177	13	2.3	Viton
	15	177	13	2.3	Kalrez
	15	177	13	2.3	Viton
Large	15	177	13	2.3	Kalrez
	15	177	13	2.3	Viton
	20	314	13	4.1	Kalrez
	20	314	13	4.1	Viton

Press-on-Cap Kits – General Applications

Cell Size	Orifice Diameter (mm)	Membrane Exposed Area (mm2)	Dosage Chamber Height (mm)	Maximum Dosage Volume (mL)	O-Ring Material
Small	9	64	4	0.25	Viton
	9	64	20	1.3	Kalrez
	11.3	100	4	0.4	Viton
	11.3	100	20	2	Kalrez
Medium	11.3	100	4	0.4	Viton
	11.3	100	20	2	Kalrez
	15	177	4	0.71	Viton
	15	177	20	3.5	Kalrez
	15	177	4	0.71	Viton
Large	15	177	20	3.5	Kalrez
	20	314	4	1.26	Kalrez
	20	314	20	6.3	Viton

Press-on-Cap Kits – Skin Applications

The small cell for skin applications is designed to accommodate testing with smaller membranes (16 mm as opposed to 25 mm diameter). In all cases, the 7 mm deep dosage chamber allows skin or synthetic membranes up to 3.0 mm thick.

Cell Size	Membrane Diameter (mm)	Orifice Diameter (mm)	Membrane Exposed Area (mm2)	Dosage Chamber Height (mm)	Maximum Dosage Volume (mL)	O-Ring Material
Small	16	11.3	100	7	0.7	Viton
Medium	25	15	177	7	1.2	Viton
Large	25	20	314	7	2.2	Viton