PAMPA variation

Composition of the PAM PA membrane varies from a purely organic solvent membrane to a purely phospholipid membrane. At the first international conference of PAM PA in 2002 (www.pampa2002.com/), it was agreed that these variations would be notated as initials or a short adjective at the head of PAMPA (e.g., BM-PAMPA for biomimetic PAMPA). The original PAMPA (Egg-PAMPA) [47], hexadecane membrane PAMPA (HDM-PAMPA) [48], BM-PAMPA [49], double sink PAMPA (DS-PAMPA) and blood-brain barrier PAMPA (BBB-PAMPA) [51] are reviewed elsewhere [3]. 

There have been many variations in the composition of artificial membranes used in a PAMPA-style analysis and each has been tailored to specific investigations. Sugano et al. [67, 68] investigated a variety of phospholipid membrane systems and experimental conditions and were able to show that by modifying the membrane it was possible to improve the predictive power of PAMPA. 

PAMPA-QSAR-VolSurf To evaiuate absorption of compounds across the membrane via a transceiiuiar route, the permeability of peptide derivatives and related compounds was measured by the PAMPA. The permeability coefficients by PAMPA were analyzed quantitatively using classical QSAR and VolSurf approaches with the physico-chemical parameters. The results from both approaches showed that hydrogen bonding ability of molecules in addition to hydrophobicity at a particular pH were significant in determining variations in PAMPA permeability coefficients. The relationship between Caco-2 cell permeability and artificial lipid membrane permeability was then determined. The compounds were sorted according to their absorption pathway in the plot of the Caco-2 cell and PAMPA permeability coefficients. 

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