Contraception (Birth Control) and Family Planning PubHealthInfo

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PubHealth.info® (a subsidiary of PakMed) presents scientific information mainly based on abstracts of articles published on a variety of public health issues/topics, particularly encompassing population planning, disease prevention, maternal and child health, and communicable and non-communicable diseases (like HIV AIDS, malaria, etc) that are affecting a significant portion of population in developing and developed countries. Here you can find abstracts of articles published on a variety of public health topics under category "Contraception (Birth Control) and Family Planning". Contraception (birth control) is a regimen of one or more actions, devices, or medications followed in order to deliberately prevent or reduce the likelihood of a woman becoming pregnant or giving birth. Therefore contraception is the utilization of various and sundry surgical procedures, devices, practices, agents, or drugs with the intention of preventing conception or impregnation (pregnancy). Methods and intentions typically termed birth control may be considered a pivotal ingredient to family planning. Birth control is a controversial political and ethical issue in many cultures and religions, and although it is generally less controversial than abortion specifically.

YEAR: 1983

CATEGORY: Contraception (Birth Control) and Family Planning

TITLE

Poly net contraceptive system.

AUTHORS

Beck LR; Tice TR

SOURCE

In: Goldsmith A, Toppozada M, ed. Long-acting contraception. Chicago, Illinois,

Northwestern University, Program for Applied Research in Fertility Regulation

[PARFR], 1983. :116-23.

ABSTRACT

The use of biodegradable polymers for the programmed delivery of contraceptive drugs is a relatively new technology

whose origin stems from the earlier work on nonbiodegradable subdermal implants. The principle involved is that

controlled release offers a means of improving the therapeutic effect of drugs, minimizes their side effects by

augmenting the amount and persistence of the drug in the vicinity of the target cell, and reduces the drug exposure to

non-target cells. This paper reports on in vivo and in vitro studies performed using biodegradable contraceptive

systems that use homopolymers and copolymers of polylactic acid (PLA), polyglycolic acid (PGA) and polylactide-co-

glycolide (PGLA) as the polymeric platform or matrix for the controlled delivery of contraceptive steroids. In the

biodegradation studies, rats were injected intramuscularly with 40 mg of norethisterone (NET) microspheres.

Evaluation of the biodegradation curves obtained from unsterilized microsphere formulations (63-125 mcm) reveals

that increasing the quantity of glycolide in the copolymer excipient causes an increase in the biodegradation rate of

the microspheres. As predicted from theory, the rate of release of NET from the microspheres decreased with time

and was fastest for smaller microspheres. The 63-125 mcm microspheres that released all of their NET in vitro in

lettle over 50 hours released NET in baboons for about 110 days, indicating that the in vitro release model provides

accelerated release and does not give a 1-to-1 correlation with in vivo rates of release. PLA and PGA have been

tested in animals in various forms including tablets, cylinders, films, powders, and microspheres and it was

concluded that microsphere size distribution can be used well to adjust the rate and duration of NET release from

the prototype DL-PLA system. Studies on humans resulted in performance similar to tests with baboons but doses

used were not high enough to inhibit ovulation for the full 6 months. Problems with diffusional release spurred

research which developed microspheres of DL-PLGA using different ratios of lactide and glycolide. The NET

release from the copolymer formulation occurs by diffusion initially and then by both diffusion and biodegradation of

the polymer; this results in maintaining higher serum levels of NET during the 2nd 1/2 of the treatment period and

reducing contraceptive failure rates. (PubHealth.info Document ID: CONT5T 2081-06)

PubHealth.info NOTE: The author(s) of this article titled, "Poly net contraceptive system.", is(are) Beck LR; Tice

TR. The source of this article is "In: Goldsmith A, Toppozada M, ed. Long-acting contraception. Chicago, Illinois,

Northwestern University, Program for Applied Research in Fertility Regulation [PARFR], 1983. :116-23.". This article

was published in 1983 in English language(s). (PubHealth.info® Document ID: CONT5T 2081-06. All rights reserved

with PubHealth.info) PIN: 22081

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