New Vertical Diffusion Cell from Copley Scientific extends options for topical semisolids and transdermal testing

Copley Scientific, a leading manufacturer of laboratory testing equipment, has introduced a new Vertical Diffusion Cell (VDC) for efficient in vitro skin permeation studies. The VDC will find application in R&D in chemical, pharmaceutical, cosmetics, and other industries. As with Copley’s existing VDCs, the new cell is designed for use with the HDT 1000 Vertical Diffusion Cell Test System; a compact heater stirrer unit for precisely controlled benchtop testing, and the Copley Vacuum De-aeration apparatus.

The new cell has a surface diameter of 15 mm, surface area of ~ 1.77 cm2 and volume of 12 mL. The cell comes with a screw cap designed for “open” or “closed” use, accommodating the complete range of skin and membranes used for semisolid and permeability testing: ‘epidermal’ (approximately 0.1 mm thick), ‘split-thickness’ (approximately 0.2-0.5 mm thick) and ‘full-thickness’ (0.5 - 1 mm thick). Copley also offers two other cells - Types ‘B’ and ‘C’, both available in “open” and “closed” top format, targeting semisolids testing in accordance with United States Pharmacopeia (USP) chapter <1724> where thin, artificial membranes are used.

Each cell comprises three main parts: a top sample holder to contain the sample of product to be tested, and a bottom reservoir with the receptor medium. These are separated by a support ring that firmly holds the membrane or skin in place. This construction allows diffusion to take place and ensures that the membrane remains in contact with the receptor medium throughout the testing procedure.

To accommodate ‘full thickness’ membranes or skin, and in contrast to the Type ‘B’ and ‘C’ cells, which use a 3-pronged spring clip, a new screw-type cell closure mechanism has been developed for the skin specific cell that ensures proper contact between the sample and the receptor medium. All components of the cell are made from FDA-approved inert materials and a side sampling arm facilitates easy filling, sample withdrawal and media replacement.

The HDT 1000 Vertical Diffusion Cell Test System (left) pictured with the new skin specific VDCs (right).


Anna Sipitanou, Business Development Manager, Copley Scientific Limited