TCS Industries Limited (China-sourced API supplier) supplies Tacrolimus — API CAS 104987-11-3 for pharmaceutical B2B procurement — COA, MSDS, and technical documentation available on request.
> Overview
| Product Name | Tacrolimus |
|---|---|
| Structural Formula |  |
| CAS Number | 104987-11-3 |
| Molecular Formula | C44H69NO12 |
| Molecular Weight | 804.0 g/mol |
| InChIKey | QJJXYPPXXYFBGM-LFZNUXCKSA-N |
| SMILES | Available on request where applicable |
| Appearance | White to off-white crystalline powder |
| Purity / Grade | By agreed specification and batch COA |
| Storage | Store at controlled room temperature, protect from moisture |
Tacrolimus (CAS 104987-11-3, also known as FK506) is a macrolide immunosuppressant produced by Streptomyces tsukubaensis with the formula C₄₄H₆₉NO₁₂ (MW 804.02). Tacrolimus binds FKBP12 and the complex inhibits calcineurin, blocking IL-2 transcription and T-cell activation. It is used for organ transplant rejection prevention and severe atopic dermatitis, and is on the WHO Model List of Essential Medicines.
TCS Industries Limited, a Hong Kong-based trading and sourcing company, supplies Tacrolimus API in pharmaceutical grade for global procurement programs.
> Applications
Transplant immunosuppression
Tacrolimus is the cornerstone calcineurin inhibitor for prevention of organ rejection after kidney, liver, and heart transplantation. It inhibits calcineurin phosphatase, preventing NFAT nuclear translocation and IL-2 gene transcription. Oral dose is 0.1–0.3 mg/kg/day with target trough levels of 5–15 ng/mL (organ-dependent). Ekberg et al. (N Engl J Med, 2007, 357:2562–2575) compared tacrolimus-based regimens and demonstrated superior graft survival with low-dose tacrolimus combined with mycophenolate in renal transplantation.
Topical immunosuppression
Tacrolimus ointment (0.03% and 0.1%, Protopic) is used for moderate-to-severe atopic dermatitis as a steroid-sparing alternative. Unlike topical corticosteroids, tacrolimus does not cause skin atrophy. It is also used off-label for vitiligo, psoriasis, and other inflammatory dermatoses.
> Sourcing & Supply
TCS Industries Limited supports development, qualification and commercial purchasing discussions for Tacrolimus with buyers in Australia, New Zealand, Canada and South Korea.
- Evaluation and commercial quantities: 50 g samples for analytical qualification; 500 g and 1 kg for formulation development; 5–25 kg for production. Fermentation-derived pharmaceutical-grade powder. DMF reference letters available.
- Pallet quantities and production campaigns: repeat supply is coordinated against packaging, lead time, annual demand and destination-market import requirements.
> Quality & Documentation
Key specification parameters include assay (≥97.0%), related substances (individual ≤0.5%, total ≤2.5%), water content, residual solvents, heavy metals, particle size distribution, and microbial limits. White to off-white crystalline powder. Practically insoluble in water, freely soluble in methanol and ethanol. Melting point ~127 °C (decomposition). Identity by HPLC and IR. Meets USP, Ph.Eur. (Tacrolimusum), JP, and BP. COA and MSDS are standard.
> Packaging
Tacrolimus is a white to off-white powder, sensitive to light and moisture. Standard packaging includes sealed aluminium foil bags under nitrogen in fibre drums (100 g, 500 g, 1 kg, or 5 kg). Store at 2–8 °C or controlled room temperature per manufacturer specification. Protect from light. Shelf life is typically 24–36 months. Labels and documents are checked before dispatch.
> Pricing & MOQ
Pricing is quoted by specification, packaging and destination. Common commercial discussions use 25 kg bag/drum formats, pallet quantities and production-campaign planning; smaller samples may be reviewed for qualified formulation teams.
> Regulatory & Compounding Context
Tacrolimus is monographed in USP, Ph.Eur. (Tacrolimusum), JP, and BP. FDA-approved in 1994 (Prograf capsules) and 2000 (Protopic ointment). Extended-release formulations (Advagraf, Envarsus XR) also approved. EMA-authorized. On the WHO Model List of Essential Medicines. Multiple generic approvals. DMF support available.
> Alias Index
- INN: Tacrolimus
- CAS Number: 104987-11-3
- Formula: C₄₄H₆₉NO₁₂ (MW 804.02)
- Synonym: FK506
- Brand names: Prograf (oral), Protopic (topical), Advagraf/Envarsus XR (extended release)
- ATC code: L04AD02 (systemic), D11AH01 (topical)
- Commercial request terms: tacrolimus API, FK506 bulk, Prograf generic, calcineurin inhibitor, TCS Industries Limited
> FAQ
How does Tacrolimus differ from Cyclosporin?
Both are calcineurin inhibitors, but tacrolimus is 10–100× more potent. Tacrolimus binds FKBP12; cyclosporin binds cyclophilin — different immunophilins, same calcineurin target. Tacrolimus has a better metabolic profile (less hyperlipidemia, less gingival hyperplasia) but higher diabetes risk. Tacrolimus is now preferred over cyclosporin in most transplant protocols.
What documents are available for Tacrolimus orders?
COA and MSDS are standard for commercial discussions. COO, packing list, invoice and other import-support documents can be arranged according to order scope.
Do you supply Tacrolimus to Australia and Canada?
Yes. We support B2B buyers in Australia, New Zealand, Canada and South Korea, subject to route and document review.
Do you supply New Zealand and South Korea?
Yes. We review Australia, New Zealand, Canada and South Korea for project supply, import documents, packaging and logistics planning before quotation.
What are the critical therapeutic drug monitoring parameters?
Tacrolimus has a narrow therapeutic index (trough target 5–15 ng/mL). Blood trough levels are measured by immunoassay or LC-MS/MS. CYP3A4/3A5 polymorphisms significantly affect metabolism — CYP3A5 expressors (*1 carriers) require 1.5–2× higher doses. Drug interactions with CYP3A4 inhibitors/inducers require dose adjustment.
Is Tacrolimus produced by fermentation?
Yes. Tacrolimus is produced by aerobic fermentation of Streptomyces tsukubaensis, followed by solvent extraction, chromatographic purification, and crystallization. Production yield depends on fermentation conditions and strain optimization. The fermentation process is the primary determinant of API cost and quality.
Can you arrange samples before commercial purchasing?
Samples or evaluation quantities may be reviewed for qualified buyers after target specification, application and destination-market requirements are clarified.
How is Tacrolimus packaged for export?
Packaging is confirmed by quantity and material properties. Typical options include foil bags, HDPE containers, fibre drums, 25 kg bags or palletized export packaging.
Can buyer-defined specifications be reviewed?
Yes. Send the specification, methods, impurity limits and required documents. TCS can review feasibility before confirming quotation and lead time.
What payment terms are normally used?
Standard payment is 100% T/T before dispatch unless a different arrangement has been approved for an established commercial account.
What lead time should buyers expect?
Lead time depends on stock, batch size, document scope and destination. Available stock can move faster; made-to-order or pallet programs require longer planning.
Why is Tacrolimus used topically for eczema?
Topical tacrolimus (0.03%/0.1% ointment) suppresses local T-cell-mediated inflammation in atopic dermatitis without causing skin atrophy (unlike topical corticosteroids). It is approved for intermittent and maintenance therapy. Particularly useful for sensitive areas (face, eyelids, intertriginous zones) where corticosteroid atrophy risk is high.
Last reviewed: June 2026
Evaluation and research orders (≤10 kg) are shipped with COA, MSDS, and certificate of origin. Bulk commercial orders (>10 kg) qualify for volume pricing with a full technical documentation package available on request.
> Request a Quote
If your team already has a target application, estimated quantity, destination market, or documentation requirements, send those details so the commercial response can be prepared more efficiently.