Colorimetric polymer films for predicting lipid interactions and percutaneous adsorption of pharmaceutical formulations.
OBJECTIVE
To develop and demonstrate a rapid and simple colorimetric film assay for evaluating lipid interactions of pharmaceutical compounds and gel formulations.


METHODS
The colorimetric assay comprises glass-supported films of phospholipids and polydiacetylene, which undergo visible and quantifiable blue-red transformations induced by interactions with amphiphilic molecules applied in very small volumes on the film surface. The color transitions are recorded by scanning of the films, and quantified through a simple image analysis algorithm.


RESULTS
We show that pharmaceutical molecules and gel formulations induce blue-red transformations after short incubation with the lipid/polydiacetylene (PDA) films. Colorimetric dose-response curves exhibit dependence upon the lipid affinity and extent of membrane binding of the pharmaceutical compounds examined. The colorimetric lipid/PDA film assay was employed for distinguishing the contributions of individual molecular components within gel formulations.


CONCLUSIONS
The colorimetric data yield insight into the degree of lipid binding of the molecules tested. The film assay is particularly advantageous for analysis of semi-solid (gel or lotion) formulations, elucidating the lipid interaction characteristics of specific molecular components within the mixtures. The new colorimetric film assay constitutes a generic, rapid, and easily applicable platform for predicting and screening interactions of pharmaceutical compounds and complex formulations with lipid barriers.
Ben-Shlush
Izek
I
Department of Chemistry and Ilse Katz Institute for Nanotechnology, Ben Gurion University of the Negev, Beersheba, Israel.
Volinsky
Roman
R
Katz
Marina
M
Scindia
Yogesh
Y
Itzhak
Racheli
R
Ohayon
Hila Tsahor
HT
Yosha
Ido
I
Jelinek
Raz
R
D000327:Adsorption; D002626:Chemistry, Pharmaceutical; D003124:Colorimetry; D005782:Gels; D008055:Lipids / Q000737:chemistry*; D000078789:Polyacetylene Polymer; D011108:Polymers / Q000737:chemistry*; D053279:Polyynes / Q000737:chemistry*; D012869:Skin Absorption
D005782:Gels; D008055:Lipids; D000078789:Polyacetylene Polymer; D011108:Polymers; D053279:Polyynes; C082361:polydiacetylene