I suppose it depends upon your purpose for generating such data. If it's to include these data in a package submissible to a regulatory agency, then a reputable lab would likely be best. In general, permeability data are reliable as long as the assays are well qualified with standard reference solutes that define the assay's performance relative to published data.

Dear Prof. Raub,

Thank yo for you reply. It has given me good insights.

Kind regards

I would like to recommend to use HPLC-photometric system. I have recently recognized that HPLC-photometric system gives very fruitful result in biochemical active-transport assay (please see file; JCB Fucoidan transport).

Nowadays, leasing company is present. I have borrowed the Shimadzu-HPLC-photometric system with data-analysis machine (Chromatopac) from a Japanese leasing company at a cost 120,000 yen (1,200 US dollar)/month (please see the above file again; our unpublished experience).

Please, contact to

Thai ORIX Leasing Co., Ltd. (TOLC)

http://www.orix.co.th/about-us/

They require qualified labs and specific conditions. Look for the specialist.