Location of Drugs Partitioned into Bilayers

There are no convenient databases for liposome log P values. Most measured quantities need to be ferreted from original publications [149,162,376,381-387,443], The handbook edited by Cevc [380] is a comprehensive collection of properties of phospholipids, including extensive compilations of structural data from X-ray crystallographic studies. Lipid-type distributions in various biological membranes have been reported [380,388,433]. 

Bauerle and Seelig [395] studied the structural aspects of amlodipine (weak base, primary amine pKa 9.26 [162]) and nimodipine (nonionizable) binding to phospholipid bilayers, using NMR, microcalorimetry, and zeta-potential measurements. They were able to see evidence of interactions of amlodipine with the cis double bond in the acyl chains. They saw no clear evidence for (=P—O- 1 H N—) electrostatic interactions. 

Herbette and co-workers [425-428,445] studied the structures of drugs bound to liposomes using a low-angle X-ray diffraction technique. Although the structural 

TABLE 5.1 Energy of Transfer (kj/mol) into Lipid Phase for 4-Methylphenol 

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