Progestasert® system

One- and three-year-duration, T-shaped PROGESTASERT systems (Figure 3), providing intrauterine delivery of progesterone for contraception (11), with concomitant reduction of menstrual blood loss (12,13). 

Figure 3. Schematic diagram of the PROGESTASERT system. (Copyright 1980 ALZA Corp.)...

PROGESTASERT systems also utilize diffusion through polymeric membranes to provide controlled administration of the therapeutic agent—in this case progesterone delivered to the uterus at an essentially constant rate of 65 yg/day for one year (Figure 5). The... 

The hormone-releasing devices have a closer resemblance to standard methods of sustained release because they involve the release of a steroid compound by diffusion [198,199]. The Progestasert, a reservoir system, is shown in Fig. 16. Progesterone, the active ingredient, is dispersed in the inner reservoir, surrounded by an ethylene/vinyl acetate copolymer membrane. The release of progesterone from this system is maintained almost constant for 1 year. The effects of release are local, with none of the systematic side effects observed with orally administered contraceptives [200-207]. 

Controlling the release of medication at the site of action is often desirable, especially for compounds that are absorbed rapidly through mucous membranes or are removed rapidly from the site of action. The approach normally reduces the systemic side effects of the agent. The application of this approach can be illustrated with the Progestasert and Pilocarpine Ocusert dosage forms. 

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.

Progestasert (progesterone) a nondegradable intrauterine contraceptive system for localized delivery of progesterone for one year. 

Delivery systems designed on this principle can be administered by different routes intrauterine such as Progestasert, implants such as Norplant, transdermal such as Transderm-Nitro, and ocular such as Ocusert. 

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. 

A second example of a reservoir controlled drug delivery system is the Progestasert inlra-uterine device (lUD), a medicated implant that is used for contraceptive purposes. In the 1960s lUDs emerged... 

Free radical polymerization in the presence of divinyl monomer Release control film for drugs, foam (lumber), film (agriculture, food wr ping), various polymer improvers Ocusert (intraocular treatment system), Progestasert (intrauterine contraceptive system), transderm-Nitro (endodermic treatment system)... 

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