Overview
Clomifene citrate is a synthetic nonsteroidal fertility agent that belongs to the selective estrogen receptor modulator (SERM) class. It is primarily used to induce ovulation in women with anovulatory disorders, such as polycystic ovary syndrome (PCOS). The compound works by blocking estrogen receptors in the hypothalamus, leading to increased secretion of gonadotropin-releasing hormone (GnRH) and subsequent stimulation of follicle-stimulating hormone (FSH) and luteinizing hormone (LH). Developed in the 1960s, clomifene citrate has become a first-line treatment for infertility due to its efficacy and relatively low cost. It is available in oral tablet form and is typically administered in a 5-day course starting early in the menstrual cycle. The drug is listed on the WHO Model List of Essential Medicines, underscoring its importance in reproductive health.
Physical and Chemical Properties
Clomifene citrate appears as a white to off-white crystalline powder with a melting point of approximately 116-118°C. It is slightly soluble in water but dissolves readily in ethanol and other organic solvents. The molecular structure consists of a triphenylethylene backbone with a chlorine substituent, contributing to its estrogenic and anti-estrogenic activities. The citrate salt form enhances the compound's stability and bioavailability. Its molecular weight is 598.09 g/mol, and it exhibits optical isomerism, with the zuclomiphene isomer having a longer half-life than the enclomiphene isomer. These properties are critical for its pharmacokinetics and therapeutic effects.
Main Applications
Clomifene citrate is predominantly used to treat anovulatory infertility, accounting for approximately 80% of its clinical applications. It is particularly effective in women with PCOS, where it helps restore regular ovulation. The drug is also used off-label for male infertility to boost testosterone production and improve sperm count. In addition to fertility treatments, clomifene citrate has been investigated for other endocrine disorders, such as hypothalamic amenorrhea and oligospermia. However, its use in these areas remains less common and typically requires careful medical supervision due to potential side effects.
Safety and Storage
Clomifene citrate should be stored in a cool, dry place below 25°C, protected from light and moisture to prevent degradation. Improper storage can lead to reduced potency or formation of impurities. The compound is generally safe when used as prescribed but may cause side effects such as hot flashes, mood swings, and visual disturbances. Handling precautions include wearing gloves and avoiding inhalation or skin contact, especially in industrial settings. Medical professionals must monitor patients for ovarian hyperstimulation syndrome (OHSS) and multiple pregnancies, which are rare but serious risks associated with its use.
B2B Procurement Guide
When procuring clomifene citrate for pharmaceutical use, buyers should prioritize suppliers with Good Manufacturing Practice (GMP) certification and ISO compliance. Key documentation includes certificates of analysis (CoA), stability data, and regulatory filings (e.g., DMFs). Bulk purchases typically require negotiation of batch-specific pricing, with reference prices ranging from $0.50 to $2.00 per tablet depending on quantity and purity. Due to its sensitive application, quality control is paramount. HPLC testing for purity (typically ≥98%) and residual solvent analysis are standard requirements. Importers should also verify compliance with regional pharmacopoeias (e.g., USP, EP) and ensure proper cold-chain logistics if applicable.