Transport, interlaboratory

PAMPA can quickly provide information about passive-transport permeability that is not complicated by other mechanisms (e.g., active transport, paracel-lular transport, and metabolism) [103], The procedure is used increasingly in pharmaceutical research in major pharmaceutical companies as well as in CROs [13, 137, 175, 179, 165, 119, 70], However, it should be stated that PAMPA to date comprises numerous methods applied in various laboratories using different membrane constituents, sink conditions, permeation times, etc., which makes interlaboratory comparison extremely difficult. Therefore, standardization and validation methods of this technique should be introduced. 

Caco-2 Human colon adenocarcinoma Well-established cell model Differentiates spontaneously and expresses some relevant efflux transporters (e.g., P-gp, MRP1-2, BCRP) Interlaboratory differences... 

Interlaboratory Transport. If it is necessary to transport chemical carcinogens from one laboratory to another, all material should be placed in a sealed, unbreakable outer container. 

The composition of the material and the parameters investigated should remain unchanged over the entire period of use of the material. The study of the material s stability in time will mainly depend on its role. If the material is foreseen to be used in a short term interlaboratory study the stability has to be monitored only over the real duration of the exercise and additionally mimic situations which may be encountered during its short lifetime e.g. transport under severe climatic conditions. Stability studies may vary from some days to several years. The sources and risk of (in)stability should be studied or known before the RM is produced. They should be monitored on the batch of (C)RMs. This study can only be performed by scientists aware of the type of material and its potential sources of instability. Consequently, collaboration with the end-users is mandatory. 

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