Methoxsalen (a therapeutic agent for vulgaris vitiligo) is a photosensitive psoralen derivative, mainly used in PUVA (psoralen + UVA) photochemotherapy for vitiligo and psoriasis.
Indications for Methoxsalen (Vitiligo Vulgaris Therapeutic Agent)
Core Therapeutic Areas
Vitiligo: By enhancing the sensitivity of epidermal melanocytes to UVA (320-400nm), it stimulates the proliferation and migration of residual melanocytes and promotes repigmentation in depigmented areas. It must be used in combination with UVA irradiation and is suitable for patients with stable non-segmental vitiligo.
Psoriasis (main indication in the package insert): Used to control severe, refractory plaque psoriasis that is unresponsive to other treatments. PUVA combination therapy should be implemented only after confirmation by biopsy.
Key Restrictions
Contraindications: Include photosensitive diseases (e.g., lupus erythematosus, porphyria), history of melanoma or squamous cell carcinoma, aphakia (high risk of cataracts), etc.
Special Warnings: Long-term treatment may increase the risk of skin cancer (especially squamous cell carcinoma) and premature aging, requiring lifelong follow-up for skin tumors.
Specifications and Properties of Methoxsalen (Vitiligo Vulgaris Therapeutic Agent)
Dosage Form Characteristics
Specifications: 10mg soft capsules per unit, packaged in amber glass bottles (NDC 0187-0650-42), with 50 capsules per bottle.
Properties: As a soft gel formulation containing natural psoralen derivatives, its bioavailability is twice that of hard capsules, and the time to reach peak concentration is shortened to 1.5-2 hours.
Pharmacological Properties
Photosensitive Mechanism: After oral administration, it forms photoadducts with DNA, inhibiting the proliferation of abnormal keratinocytes (for psoriasis) or stimulating melanin production (for vitiligo).
Metabolic Characteristics: 95% of the drug is metabolized by the liver and excreted in urine within 24 hours, with a half-life of approximately 2 hours.
Storage Methods for Methoxsalen (Vitiligo Vulgaris Therapeutic Agent)
Environmental Requirements
Temperature: Store at 25°C (77°F); short-term fluctuations between 15°C and 30°C (59°F and 86°F) are allowed.
Light Protection: The original amber bottle can effectively block ultraviolet rays; avoid direct sunlight exposure.
Safety Precautions
Child Protection: Store out of the reach of children to prevent accidental ingestion and subsequent phototoxic reactions.
After Opening: It is recommended to use up the product within 6 months. Discard the capsules if they become soft or leak.
