Poly , levonorgestrel release

Controlled release fiber systems based on aliphatic polyesters were investigated by Dunn and Lewis (51-54). The feasibility of hollow fibers spun from poly (L-lactide) and containing the contraceptive steroid levonorgestrel has been demonstrated (55). 

H., In vitro and in vivo release of levonorgestrel from poly-(ortho esters). II. Crosslinked polymers, J. Control. Rel., 1, 233-238, 1985. 

FIGURE 6.25 The release of levonorgestrel from a poly(orthoester) slab containing 30% drug and 2% calcium lactate. [Graph reconstructed from data by Heller et al. in Controlled Release of Bioactive Materials, R. W. Baker (Ed.), Academic Press, New York, 1980, p. 1.]... 

Wang SH, Zhang LC, Lin F, Sa XY, Zuo JB, Shao QX et al. Controlled release of levonorgestrel from biodegradable poly(D,L-lactide-co-glycolide) microspheres In vitro and in vivo studies. International Journal of Pharmaceutics. September 14, 2005 301(l-2) 217-225. PubMed PMID 16040213. 

Fig. 2. Cumulative release of levonorgestrel from 6.3 mm poly(ortho ester) discs fabricated at different temperatures. Polymers prepared from 3,9-bis(ethylidene 2,4,8,10-tetraoxaspiro[5,5]undecane) and various diols.

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