Pharmacokinetics of Etonogestrel and Ethinylestradiol Released from a Combined Contraceptive Vaginal Ring

Timmer, C. J.; Mulders, T.M.T.

doi:10.2165/00003088-200039030-00005

Cited by 233 publications

(135 citation statements)

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“…These extended periods of steady drug release are in concurrence with commercially available EVAc devices [37]. This timeframe is also in concurrence within the current device retention times being examined for contraceptive vaginal rings [38].…”

Section: Discussionsupporting

confidence: 72%

Cervical cancer treatment with a locally insertable controlled release delivery system

Keskar

Mohanty

Gemeinhart

et al. 2006

Journal of Controlled Release

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Local delivery of cancer chemotherapeutics enables sustained drug levels at the site of action thereby reducing systemic side effects. A novel insertable polymeric drug delivery system for cervical cancer treatment is presented. Cisplatin, the first line of therapy employed for cervical cancers, was incorporated in a poly(ethylene-co-vinyl acetate) (EVAc) device that is similar to those currently used for vaginal contraceptive delivery. Cisplatin crystals were uniformly dispersed in the polymeric system without undergoing significant dissolution in the polymer matrix. Cisplatin dissolution from the devices was biphasic, consistent with a matrix-type controlled-release system with an initial rapid release phase followed by a slower, linear release phase. Depending on the drug loading in the polymeric devices, the near-linear release phase varied in rate according both empirical, linear curvefitting (0.38±0.15 μg/day to 46.9±10.0 μg/day) and diffusion analysis based upon diffusion through a porous structure (D app from 1.3±0.5×10 −9 cm 2 /s to 5.8±0.3×10 −12 cm 2 /s). The devices were tested for in vitro activity and found to be effective against both HPV positive and HPV negative cervical cancer cell lines. Preliminary studies indicate that this delivery system would be a good candidate for investigation as a choice of treatment in cervical cancers.

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Section: Discussionsupporting

confidence: 72%

Cervical cancer treatment with a locally insertable controlled release delivery system

Keskar

Mohanty

Gemeinhart

et al. 2006

Journal of Controlled Release

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“…There seems to be little difference between the AUCs when LNG is administered by the two routes. Timmer and Mulders [37] have also shown increased bioavailability of some contraceptive steroids when administered intravaginally compared to oral administration. Thus, the vaginal route of drug delivery may be the preferable route of administration for the contraceptive steroids [38].…”

Section: Discussionmentioning

confidence: 99%

Pharmacokinetic study to compare the absorption and tolerability of two doses of levonorgestrel following single vaginal administration of levonorgestrel in Carraguard® gel: a new formulation for “dual protection” contraception

et al. 2007

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Objective: The study was conducted to assess levonorgestrel (LNG) serum levels achieved after a single administration of two different doses of Carraguard vaginal gel containing LNG (CARRA/ LNG), designed for use as microbicide and contraceptive for potential dual-protection. Materials and methods:This was a randomized double-blind pharmacokinetic study conducted in 12 subjects enrolled at two centers. Each subject received a single vaginal administration of CARRA/LNG containing either 0.75 or 1.5 mg LNG per 4 mL of gel on day 10-12 of the menstrual cycle. LNG serum levels were measured at 0, 1, 2, 4, 8 and 12 h after administration and for the following seven days. LH and progesterone (for a preliminary evaluation of effect on the ovarian function) as well as SHBG were measured in the daily samples.Results: Serum LNG maximum concentrations (C max ) were 14.1 ± 5.1 and 11.7 ± 6.5 nmol/L and T max was 12.0 and 6.0 h for the low and high dose, respectively, with large intersubject variability within the first 48 h. Mean levels at 96 h were 10% of C max . Differences in AUC between both doses were not statistically significant. SHBG levels decreased approximately 25% by day 4 after administration. Luteal activity was observed in 3/6 and 5/6 of the subjects in the low and high dose group, respectively. Conclusion:This study demonstrates that the CARRA/LNG gel can sustain elevated serum levels of the contraceptive steroid for up to 96 h after a single application. The serum levels attained with the 0.75 mg formulation are in the range expected to perturb the ovulatory process as observed in some subjects. The lack of correlation between the administered dose and serum concentrations of the steroid may be related to a rate-limiting absorption of LNG from the vaginal mucosa. The results reported here suggest that the CARRA/LNG formulation has good potential to become a dualprotection method, possibly preventing conception and sexually transmitted infections.

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“…60 It is effective (Pearl index, 1-3), 62 controls the menstrual cycles, 63 and has the advantage of a lower concentration of ethinyl estradiol compared with combined hormonal contraceptives, thus minimizing the adverse events related to ethinyl estradiol. 62,64,65 In a randomized trial, the vaginal ring group showed that exposure to ethinyl estradiol was significantly 3.4 times lower than in the patch group and 2.1 times lower than in the combined hormonal contraception group. Serum ethinyl estradiol levels of patients showed much lower variations with the vaginal ring than with the patch or combined hormonal contraceptives.…”

Section: The Vaginal Ringmentioning

confidence: 99%

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Yousif

Bridson

Halawa³

2016

Exp Clin Transplant

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There is a misconception among transplant clinicians that contraception after a successful renal transplant is challenging. This is partly due to the complex nature of transplant patients, where immunosuppression and graft dysfunction create major concerns. In addition, good evidence regarding contraception and transplant is scarce, with most of the evidence extrapolated from observational and case-controlled studies, thus adding to the dilemma of treating these patients. In this review, we closely analyzed the different methods of contraception and critically evaluated the efficacy of the different options for contraception after kidney transplant. We conclude that contraception after renal transplant is successful with acceptable risk. A multidisciplinary team approach involving obstetricians and transplant clinicians to decide the appropriate timing for conception is recommended. Early counseling on contraception is important to reduce the risk of unplanned pregnancies, improve pregnancy outcomes, and reduce maternal complications in patients after kidney transplant. To ascertain appropriate advice on the method of contraception, individualizing the method of contraception according to a patient's individual risks and expectations is essential.

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Pharmacokinetics of Etonogestrel and Ethinylestradiol Released from a Combined Contraceptive Vaginal Ring

Cited by 233 publications

References 5 publications

Cervical cancer treatment with a locally insertable controlled release delivery system

Cervical cancer treatment with a locally insertable controlled release delivery system

Pharmacokinetic study to compare the absorption and tolerability of two doses of levonorgestrel following single vaginal administration of levonorgestrel in Carraguard® gel: a new formulation for “dual protection” contraception

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