Progestasert intrauterine device

Fig. 16 Schematic diagram of the Progestasert intrauterine device for the release of progesterone.

Figure 12.9 Progestasert intrauterine device (IUD) designed to deliver progesterone for contraception at 65 p,g/day for 1 year [19]...

The Progestasert intrauterine device (lUD) is a contraceptive lUD marketed in the United States. It is a white, T-shaped unit constructed of ethylene-vinyl acetate copolymer containing titanium dioxide. It releases progesterone at a rate of 65 pg/day for 1 year, controlled by an outer coat of ethylene-vinyl acetate... 

The most well known commercial reservoir controlled release systems deliver hormones for contraception from hydrophobic polymers. The Norplant subcutaneous device controls the release of levonorgestrel with silicone rubber, and the Progestasert intrauterine device (lUD) releases progesterone from reservoir devices of ethylene vinyl acetate. In the field of insecticides, reservoir dispensers called BioLure were developed to provide zero-order release ofinsect pheromones to disrupt mating (Smith et al, 1983). The dispenser consists of a slab configuration with a rate-controlling membrane, with constant release described by Eq. 1. 

As of 1994, there were approximately 47 progestin-containing contraceptive dmg formulations sold in the United States for use as oral contraceptives (Table 3). In addition, there are three nonoral contraceptive formulations containing progestins ie, one injectable (Depo-Provera), one as an intrauterine device (lUD) (Progestasert), and one implantable (Norplant). Of the oral formulations, all but two also contain an estrogen component, ethynylestradiol. 

Ethylene vinyl acetate has also found major applications in drug delivery. These copolymers used in drug release normally contain 30-50 wt% of vinyl acetate. They have been commercialized by the Alza Corporation for the delivery of pilocarpine over a one-week period (Ocusert) and the delivery of progesterone for over one year in the form of an intrauterine device (Progestasert). Ethylene vinyl acetate has also been evaluated for the release of macromolecules such as proteins. The release of proteins form these polymers is by a porous diffusion and the pore structure can be used to control the rate of release (3). Similar nonbiodegradable polymers such as the polyurethanes, polyethylenes, polytetrafluoroethylene and poly(methyl methacrylate) have also been used to deliver a variety of different pharmaceutical agents usually as implants or removal devices. 

An innovative progesterone-containing device (Progestasert) has been made available as a long-lasting intrauterine contraceptive. It contains 38 mg of the drug in a silicone oil solution, which on proper insertion releases 63 jig of progesterone per 24 hours for periods up to 1 year. The contraceptive effects of the device itself (an intrauterine device, IUD) is believed to be enhanced by the hormone s local effect on the endometrium. 

Progesterone undergoes rapid first-pass metabolism, but high-doses (e.g., 100—200 mg) of micronized progesterone (prometrium) are orally effective. Progesterone also is available in oil solution for injection, as a vaginal gel (CRINONE, PROCHIEVE), and as a slow-release intrauterine device (PROGESTASERT)for contraception. 

EVA copolymers are also used in fabricating Progestasert and Ocusert which are an intrauterine and an ocular drug delivery device for pilocarpine and progesterone, respectively. These are discussed in Chapters... 

Figure 8.34 Examples of drug-delivery systems employing polymeric membranes, (o) Ocusert system for the eye with two rote-controlling membranes, (b) Tronsiderm system for transdermal medication with one rote-controlling layer, (c) The Progestasert device for intrauterine insertion in which the body of the device serves as the rote-controlling barrier, (d) The oral Oros device in which the membrane is o semipermeable membrane which forbids drug transport, allowing water ingress only.

Note. Progestasert, Alza an intrauterine contraceptive device consists of 38mg of progesterone in silicone oil. In this instance, the drug is believed to increase the contraceptive effectiveness of the said device by a local effect on the endometrium followed by effects upon the motility of sperm, capacitation and metabolism.]... 

Medical Letter (1976) Progestasert - a new intrauterine contraceptive device. 18, 65. 

---