Molecular Weight

114.14 g/mol

Molecular Formula

C₆H₁₀O₂

XLogP3

Hydrogen Bond Donor Count

Hydrogen Bond Acceptor Count

Rotatable Bond Count

Exact Mass

114.068079557 g/mol

Monoisotopic Mass

114.068079557 g/mol

Topological Polar Surface Area

26.3 Å²

Heavy Atom Count

Formal Charge

Complexity

88.5

Isotope Atom Count

Defined Atom Stereocenter Count

Undefined Atom Stereocenter Count

Defined Bond Stereocenter Count

Undefined Bond Stereocenter Count

Covalently Bonded Unit Count

The incorporation of estramustine into biodegradable waxy type copolyesters, prepared by direct copolycondensation of epsilon-caprolactone and delta-valerolactone in the absence of catalysts, to apply as implantable matrices for drug delivery systems, is described and the in vivo capability of the implantable device was evaluated by implanting into the back of male rats. The copolyesters are much more subject to erosion than their homopolyesters, in which the degradation is further accelerated by the action of lipase type enzyme. The drug release, although accompanying a burst phenomenon in the initial stage, was kept constant throughout an experimental period of 19 wk from the first to twentieth wk. In this case, the release pattern was parallel to the degradation pattern, in support of the release being the rate-limiting step in the degradation of the polymer. The results showed about 75% of the initial drug content was still present in the device even after 20 wk of implantation. This finding means that the biodegradable poly(epsilon-caprolactone-co-delta-valerolactone) wax is useful as an implantable matrix for a drug delivery system which controls the release over a relatively long period of time. The in vivo activity of the drug was demonstrated by observing atrophy of the seminal vesicles and ventral prostate in male rats 10 wk after implantation.

The release of levonorgestrel from a poly(epsilon-caprolactone) capsule implanted subdermally in 8 women was studied over 5 menstrual cycles. All subjects except one experienced suppression of ovulation while the capsule was in place (one cycle). The capsules contained 16 mg of drug and 61 mg of ethyl oleate as a suspending vehicle. There was a wide range of serum levels of the drug. Suppression of ovulation appeared to occur at a serum level of 300 pg/ml or greater.