title: Release of 19-nor-testosterone type of contraceptive steroids through different drug delivery systems into serum and breast milk of lactating women.
abstract: The release of contraceptive steroids through different drug delivery systems into serum and breast milk was investigated in a group of lactating women. Four women in each group were taking either a low dosage progestogen compound like norethisterone (NET) 350 micrograms or d-norgestrel (d-Ng) 50 micrograms alone or low dosage combination pills containing NET 1 mg or d-Ng 150 micrograms with 30 micrograms ethinyl estradiol (EE2) or a biodegradable implant containing 25 mg NET or d-Ng. Peak levels in plasma and milk were seen in oral contraceptive users around 2 hours. Of the two low dosage progestogen compounds, d-Ng was below the detection limit in milk within 4 hours whereas NET was still detectable at the 24-hour interval. In contrast to this, because of the larger quantity of steroids in the combination pills, the NET/d-Ng levels in serum as well as in milk were high throughout the 24-hour period. With the subdermal route because of the sustained low release of the drug from the biodegradable implants, the levels in milk were below the detection limit within a day with d-Ng and within a week with NET.
mesh_terms: D004343:Drug Implants; D004997:Ethinyl Estradiol / Q000097:blood / Q000378:metabolism*; D005260:Female; D006801:Humans; D008895:Milk, Human / Q000032:analysis*; D009640:Norethindrone / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism*; D009644:Norgestrel / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism*
chemical_list: D004343:Drug Implants; D009644:Norgestrel; D004997:Ethinyl Estradiol; D009640:Norethindrone