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Effect of polymer composition on steroid permeation: Membrane permeation kinetics of androgens and progestins

1987; Elsevier BV; Volume: 5; Issue: 1 Linguagem: Inglês

10.1016/0168-3659(87)90039-3

1873-4995

Ying Sun, Musa Ghannam, Kakuji Tojo, C. W., Chi-Long Lee, Katherine L. Ulman, Kent R. Larson,

Protein purification and stability

The permeation rates of 10 androgenic and 7 progestagenic steroids through synthetic membranes fabricated from poly(trifluoropropylmethylsiloxane) (PFMS), poly (dimethylsiloxane) (PDMS) and the copolymer of PDMS with poly(ethylene oxide) (PEO) and poly (methyl methacrylate) (PMMA) were investigated and found to be profoundly affected by the chemical structure of penetrants and/or the copolymer composition. The permeation rate for both groups of steroids was observed to decrease in the order of PDMS > PFMS > PDMS/PEO/PMMA copolymer. This can be attributed to the increase in membrane polarity, which causes a decrease in the polymer solubility of steroids, and the incorporation of the high-Tg glassy polymer segments, which leads to a reduction in the diffusivity in the polymer. The increase in the PDMS block size tends to promote the permeation of steroids, which can be explained in light of the increase in the size of more permeable PDMS domain. Incorporation of PMMA blocks into PDMS drastically decreases the rate of steroid permeation due to the presence of less permeable "hard" PMMA domains, while addition of PEO produces an enhancing effect on the permeation of less lipophilic steroids such as testosterone.