A comparison of bleeding patterns and cycle control using two transdermal contraceptive systems: a multicenter, open-label, randomized study

Transdermal delivery of combined hormonal contraception: a review of the current literature

The transdermal patch provides an effective and convenient option for hormonal contraception. The patch currently on the US market contains 150 µg norelgestromin and 35 µg ethinylestradiol (EE). The 20 cm² patch is applied once weekly for 3 weeks, followed by a patch-free week, for a 21–7 cycle. Typical failure rates are similar to that of combined oral contraceptives (COCs). Transdermal delivery results in less peaks and troughs of estrogen, but a higher total estrogen exposure compared with COCs. Though studies show mixed results, the risk of developing venous thromboembolism (VTE) is about twice as high with the patch as with COCs; however, the absolute risk of VTE remains low. The side effect profile is similar to that of COCs, with slightly higher rates of breast tenderness plus a unique adverse effect of application site reactions. Two new patches have been developed, one containing gestodene and EE in Europe and another containing levonorgestrel and EE. Overall, the patch provides an alternative to COCs for women who want autonomy and the benefit of not needing to take a pill daily, with similar efficacy and tolerability.

An open-label, two-period comparative study on pharmacokinetics and safety of a combined ethinylestradiol/gestodene transdermal contraceptive patch

We investigated the pharmacokinetics and safety profiles of a newly developed combined ethinylestradiol (EE)/gestodene (GSD) transdermal contraceptive patch after a single-dose administration and compared with the market available tablet formulation in healthy adult subjects. An open-label, two-period comparative study was conducted in 12 healthy women volunteers. A single dose of the study combined EE/GE transdermal contraceptive patch and oral tablet (Milunet^®) were administered. Blood samples at different time points after dose were collected, and concentrations were analyzed. A reliable, highly sensitive and accurate high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC/MS/MS) assay method was developed in this study to determine the plasma concentrations of EE and GSD. Compared to the tablet, the study patch had a significantly decreased maximum plasma concentration (C_max), extended time to reach the C_max and half-life, as well as increased clearance and apparent volume of distribution. The half-lives of EE and GSD of the patch were 3.3 and 2.2 times, respectively, than the half-life of the tablet. The areas under the plasma concentration–time curve (AUCs) of EE and GSD of the patch were 8.0 and 16.2 times, respectively, than the AUC of the tablet. No severe adverse event was observed during the whole study, and the general safety was acceptable. In conclusion, compared to the oral tablet Milunet, the study contraceptive patch was well tolerated and showed potent drug exposure, significant extended half-life and stable drug concentrations.

Bleeding pattern and cycle control of a low-dose transdermal contraceptive patch compared with a combined oral contraceptive: a randomized study

OBJECTIVE(S)

The aim of this study was to investigate the bleeding pattern and cycle control of a contraceptive patch containing 0.55 mg ethinyl estradiol (EE) and 2.1 mg gestodene (GSD) compared with a combined oral contraceptive (COC) containing 0.02 mg EE and 0.1 mg levonorgestrel (LNG).

STUDY DESIGN

In this phase III, randomized, controlled, double-blind, double-dummy, multicenter trial, healthy women aged 18-45 years (smokers aged 18-35 years) received either the EE/GSD patch and a placebo tablet (n=171), or a placebo patch and the COC (n=175) for seven 28-day cycles. Bleeding control was assessed in two 90-day reference periods.

RESULTS

Mean number of bleeding/spotting days was comparable across treatment groups in both reference periods (p>.05). Mean number of bleeding/spotting episodes was also comparable in reference period 1; however, there were fewer bleeding/spotting episodes for COC in reference period 2 (3.4 versus 3.1; p=.01). Mean length of bleeding/spotting episodes was comparable across treatment groups for both reference periods (p>.05). Withdrawal bleeding occurred consistently in both groups over the entire treatment period, but its absence was more common in the COC group in cycles 4 and 6 of reference period 2 (p<.01). Intracyclic bleeding was comparable between groups.

CONCLUSION(S)

Bleeding pattern and cycle control with the EE/GSD patch was comparable to an EE/LNG-containing COC.

IMPLICATIONS STATEMENT

The findings suggest that bleeding patterns with the EE/GSD patch are similar to an EE/LNG-containing COC, except for absence of withdrawal bleeding, which was less common in patch users. The EE/GSD patch may constitute an additional contraceptive option for women.