Franz diffusion cell
The Franz diffusion cell or just Franz cell is an apparatus for testing the release of active ingredients from semi-solid preparations in the laboratory . Using this in vitro method, animal experiments can be reduced and new formulations of ointments or creams can be tested and compared at low cost.
construction
The cell is made of borosilicate glass and has a donor chamber and an acceptor chamber. Both chambers are separated from one another either by a synthetic membrane or a natural product such as pig skin. The donor chamber contains the semi-solid product to be examined, such as B. a cream, ointment or gel. The acceptor chamber, on the other hand, contains a medium (mostly aqueous buffers or alcohol mixtures) from which samples are taken at defined times. The medium is constantly stirred using a small magnetic stirrer. The cell is heated to a temperature of 32 ° C in order to mimic the physiological temperature of the skin.
execution
The samples taken from the acceptor chamber are processed using a suitable method, e.g. B. UV spectroscopy or by means of high performance liquid chromatography (HPLC), measured. Together with the known size of the membrane, the amount of active ingredient released per square centimeter can be calculated. Normally, the calculated values for six Franz cells are plotted against time. The release diagram obtained is a measure of the release rate and can enable conclusions to be drawn about the formulation as well as the diffusion of the active ingredient through the skin.
Individual evidence
- ↑ <725> TOPICAL AND TRANSDERMAL DRUG PRODUCTS — PRODUCT PERFORMANCE TESTS. (No longer available online.) In: USP. USP, archived from the original on March 2, 2012 ; accessed on February 17, 2017 (English). Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
