Can TXA Injection Be Used to Compound a 10% TXA Solution?
Yes, tranexamic acid injection formulations can be diluted to create compounded solutions for intradermal use in melasma treatment, with concentrations ranging from 4 mg/mL to 10 mg/mL (1% solution) being most commonly studied and recommended. 1, 2
FDA-Approved Formulation Specifications
The FDA-approved tranexamic acid injection contains 1,000 mg tranexamic acid (100 mg/mL) as a clear, colorless solution in 10 mL single-dose vials. 3 This injectable formulation serves as the base product that can be diluted with saline to achieve lower concentrations suitable for intradermal melasma treatment.
Recommended Concentrations for Melasma Treatment
Evidence-Based Concentration Guidelines
The American Academy of Dermatology recommends using a 4% TXA solution (40 mg/mL) prepared by diluting with saline for intradermal microinjections when combining injection technique with microneedling. 1
A 10 mg/mL concentration (1% solution) for intradermal injections has demonstrated superior efficacy with 62.7% MASI score reduction compared to 4 mg/mL concentration (39.1% reduction) in head-to-head trials. 2
Topical 10% TXA cream (100 mg/mL) produces only fair improvement with 4.2% MASI reduction, making it the least effective delivery method. 2
Critical Distinction: Concentration vs. Route of Administration
The confusion in your question likely stems from mixing concentration percentages with delivery routes. The evidence clearly shows:
- For intradermal injection: Use 4-10 mg/mL concentrations (0.4%-1% solutions), NOT 10% solutions 1, 2
- For topical application: 10% concentration (100 mg/mL) can be used but shows minimal efficacy 2
- A 10% injectable solution would be 100 mg/mL, which is the undiluted FDA formulation and is NOT appropriate for intradermal injection without dilution 3
Practical Compounding Protocol
How to Prepare Appropriate Concentrations
Starting with FDA-approved TXA injection (100 mg/mL): 3
- For 4 mg/mL solution: Dilute 1 mL of TXA injection with 24 mL normal saline (1:25 dilution)
- For 10 mg/mL solution: Dilute 1 mL of TXA injection with 9 mL normal saline (1:10 dilution)
Efficacy Hierarchy of TXA Delivery Methods
The American Academy of Dermatology and supporting research establish this clear hierarchy: 1, 4, 5
- Intradermal injection (4-10 mg/mL): Most effective
- Microneedling with TXA: Comparable efficacy to injection with higher patient satisfaction 6
- Oral TXA (250 mg twice daily): Effective but systemic side effects 1, 5
- Topical TXA (10%): Least effective 2, 5
Superior Alternative: PRP Combined with Oral TXA
Intradermal PRP injections demonstrate higher efficacy than intradermal TXA injections with similar side effect profiles. 7, 8, 9 The combination of PRP injections with oral TXA 250 mg twice daily achieves 90.48% total efficacy versus 73.68% with TXA alone, with lower disease recurrence rates. 7, 8
Common Pitfall to Avoid
Do not use undiluted 100 mg/mL (10%) TXA injection for intradermal administration. This concentration is designed for intravenous use in bleeding disorders, not dermatologic intradermal injection. 3 The appropriate intradermal concentrations are 25-fold to 10-fold lower (4-10 mg/mL). 1, 2
Treatment Protocol When Using Diluted TXA Injections
- Administer intradermal injections every 2 weeks for 6 sessions 2, 6
- Combine with strict sun protection (SPF 50+ reapplied every 2-3 hours) 1, 8
- Measure treatment response using mMASI scores at baseline, 4 weeks, 8 weeks, and end of treatment 1, 9
- Consider switching to PRP injections if inadequate response, as PRP shows superior efficacy 7, 8, 9