Progestasert

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. 

Alza Corp. has also developed an iatrauteriae device, Progestasert, designed to release progesterone [57-83-0] by diffusion through a rate-controlling membrane for up to one year. The dmg reservoir is built into a T-shaped device that is inserted intravaginaHy (15). 

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. 

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

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]. 

See also Economic evaluation Profitability criteria, 9 544-546 Profitability diagram, 9 544 Profitability spreadsheet, 9 543 Progestasert, 18 711 Progesterone, 13 3 Progil process, 18 823 Proglycem, 5 169... 

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

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... 

Several commercial examples of such devices have been introduced. The ALZA Corporation markets a device called OCUSERT wiiich is placed in the cul de sac of the eye and releases pilocarpine to control glaucoma. Another ALZA product called PROGESTASERT is placed in the uterus and releases progesterone to effect birth control Each of these are macroscopic devices however, microenr psulation is... 

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. 

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... 

Fig. 4 Diagrammatic illustration of a unit of Progestasert lUD, showing various structural components (A) and the in vitro and in vivo delivery rate profiles of progesterone for up to 400 days (B).

The use of rate-limiting membranes to control the movement of dmgs from a reservoir has been referred to above. Implants of silicone rubber or other appropriate polymeric material in which dmg is embedded can be designed by choice of polymer, membrane thickness and porosity, to release dmg at preselected rates. The Progestasert device (Fig. 8.34c) is designed to be implanted into the uterine... 

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. 

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. 

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