Vaginal Administration of Contraceptives

Abstract

While contraceptive drugs have enabled many people to decide when they want to have a baby, more than 100 million unintended pregnancies each year in the world may indicate the contraceptive requirement of many people has not been well addressed yet. The vagina is a well-established and practical route for the delivery of various pharmacological molecules, including contraceptives. This review aims to present an overview of different contraceptive methods focusing on the vaginal route of delivery for contraceptives, including current developments, discussing the potentials and limitations of the modern methods, designs, and how well each method performs for delivering the contraceptives and preventing pregnancy.

Application of Sol–Gels for Treatment of Gynaecological Conditions—Physiological Perspectives and Emerging Concepts in Intravaginal Drug Delivery

“…Weakly acidic drugs (pKa < 5.5, e.g., tenofovir) remain unionised under physiological conditions, while weakly basic drugs (pKa 8.5–10.5, e.g., itraconazole, voriconazole) are ionised in the acidic environment of the lower FRT [ 77 , 78 , 79 , 80 ]. However, a fluctuating pH, especially that evident in the vagina, can directly affect drug ionisation, which in turn impacts solubility and ultimately drug absorption.…”

“…Hormonal contraceptives based on combined oestrogen and progestin, or progestin alone, are used widely for contraception as well as non-contraceptive purposes such as irregular periods, heavy bleeding, and anaemia, and are available as combined oral contraceptives (COCs), emergency pills, intramuscular depots, subdermal implants, and intrauterine devices [ 120 , 121 ]. Despite the availability of several hormonal vaginal and non-vaginal contraceptives, vaginal contraceptives are gaining in popularity due to the advantages that the vaginal route offers compared to non-vaginal routes [ 78 ]. Nevertheless, high costs, side effects such as weight gain, low libido, depression, increased risk of breast cancer, cervical cancer, and venous thromboembolism, the necessity of strict adherence to the dosage regimen of COCs, and the requirement of trained personnel for vaginal use reduce patient compliance [ 78 , 121 , 122 ].…”

“…Despite the availability of several hormonal vaginal and non-vaginal contraceptives, vaginal contraceptives are gaining in popularity due to the advantages that the vaginal route offers compared to non-vaginal routes [ 78 ]. Nevertheless, high costs, side effects such as weight gain, low libido, depression, increased risk of breast cancer, cervical cancer, and venous thromboembolism, the necessity of strict adherence to the dosage regimen of COCs, and the requirement of trained personnel for vaginal use reduce patient compliance [ 78 , 121 , 122 ]. This has resulted in almost 99 million unplanned pregnancies worldwide annually, highlighting the need for novel controlled-release contraceptives that can reduce side effects, and so aid in patient compliance and adherence [ 78 , 121 , 122 ].…”

“…Nevertheless, high costs, side effects such as weight gain, low libido, depression, increased risk of breast cancer, cervical cancer, and venous thromboembolism, the necessity of strict adherence to the dosage regimen of COCs, and the requirement of trained personnel for vaginal use reduce patient compliance [ 78 , 121 , 122 ]. This has resulted in almost 99 million unplanned pregnancies worldwide annually, highlighting the need for novel controlled-release contraceptives that can reduce side effects, and so aid in patient compliance and adherence [ 78 , 121 , 122 ]. Recently, in May, 2020, a relatively safer and more convenient non-hormonal vaginal contraceptive gel (Phexxi TM ) was approved by the U.S. Food and Drug Administration (FDA), which is appealing to women not preferring hormonal drugs due to pre-existing medical conditions or simply wanting to avoid hormone-associated side effects [ 123 ].…”

“…Furthermore, low doses of GnRH agonists or oral contraceptives used prior to in vitro fertilisation in endometriosis-related infertility often fail to address the systemic effects of the therapy [ 115 ]. On the other hand, higher doses of hormones increase their efficacy but result in severe side effects, such as weight gain, uterine bleeding, mood changes, and even intolerance [ 78 , 115 ]. In such circumstances, VDD can safely deliver these hormones to the target site with minimal systemic effects and improve the patient experience and fertility rate.…”