Carbamazepine – the Active Pharmaceutical Ingredient (API)
| Item | Detail |
|------|--------|
| Generic name | Carbamazepine |
| Drug class | Anticonvulsant / Mood‑stabilizer |
| Chemical formula | C15H12N2O |
| Molecular weight | 236.26 g mol⁻¹ |
| CAS Registry Number | 60‑30‑8 |
| Appearance | White to off‑white, crystalline powder (often slightly yellowish) |
| Solubility | Slightly soluble in water, highly soluble in ethanol, acetone, and dimethyl sulfoxide (DMSO). |
| Typical API form | Fine crystalline powder, often packed in 1 g or 5 g vials for compounding or bulk purchase. |
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Why carbamazepine is used
| Indication | Typical starting dose (oral) |
|------------|------------------------------|
| Epilepsy (partial & generalized seizures) | 200 mg twice daily |
| Trigeminal neuralgia | 100–200 mg twice daily |
| Bipolar disorder (maintenance) | 400–800 mg/day, titrated slowly |
| Migraine prophylaxis | 200 mg twice daily (in some regions) |
(Exact dosing is individualized and should be determined by a qualified prescriber.)
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How the API is incorporated into finished products
1. Tablets / Capsules
- Carbamazepine API is blended with excipients (e.g., lactose, microcrystalline cellulose, magnesium stearate) to form a uniform tablet or capsule mix.
- The blend is compressed or filled, then coated (if needed) for controlled release or enteric protection.
2. Extended‑Release (ER)
- ER formulations often use polymer matrices (e.g., hydroxypropyl methylcellulose) or osmotic pump systems to release carbamazepine over 12–24 h.
- The ER product contains the same API but is designed for once‑ or twice‑daily dosing, improving adherence.
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Common side‑effects & safety notes
| System | Typical adverse effects |
|--------|------------------------|
| Central nervous system | Dizziness, drowsiness, ataxia, vertigo, headache |
| Dermatologic | Rash, Stevens‑Johnson syndrome (rare but serious), exfoliative dermatitis |
| Hematologic | Agranulocytosis, leukopenia, thrombocytopenia (rare) |
| Metabolic | Elevated liver enzymes, hyponatremia (especially in elderly) |
| Reproductive | Teratogenic; contraindicated in pregnancy unless benefits outweigh risks. Contraception is recommended for women of childbearing potential. |
Always consult a healthcare professional before starting, stopping, or changing carbamazepine therapy. Routine monitoring (CBC, liver enzymes, serum sodium, and drug levels in some cases) is often recommended.
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Interactions
- Enzyme induction: Carbamazepine induces CYP3A4 and CYP1A2, increasing clearance of drugs such as warfarin, oral contraceptives, and some antidepressants.
- Enzyme inhibition: In combination with CYP1A2 inhibitors (e.g., fluvoxamine) plasma concentrations can rise, heightening the risk of toxicity.
- Serotonin syndrome: Concurrent use with serotonergic agents (SSRIs, MAOIs, tramadol) can precipitate serotonin syndrome.
- Other: It can lower serum levels of lithium, levothyroxine, and some antiepileptics (e.g., phenytoin).
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Typical API suppliers
| Supplier (US) | Product code / link |
|---------------|---------------------|
| Sigma‑Aldrich | 53788 (Carbamazepine) |
| TCI America | 12423 (Carbamazepine) |
| Alfa Aesar | 13838 (Carbamazepine) |
| Acros Organics | 44535 (Carbamazepine) |
(Availability varies by region and regulatory status. Bulk purchases are generally for research or compounding use; the API is not sold for direct consumption without proper formulation.)
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Key take‑away
Carbamazepine is a well‑established anticonvulsant and mood stabilizer. Its API is a crystalline powder that is blended with excipients to produce tablets or capsules. While the drug is widely available, it must be used under prescription, with appropriate monitoring for side‑effects and drug interactions. If you’re looking to procure the API for legitimate research or compounding, contact a licensed chemical supplier and ensure you comply with local regulations.