Last updated: March 2, 2026
What is ACTHREL?
ACTHREL (marketed under the brand name Acthar Gel) is a repository corticotropin injection indicated for multiple conditions, including multiple sclerosis relapses, infantile spasms, and rheumatoid arthritis. It comprises natural porcine corticotropin and is delivered via intramuscular or subcutaneous injection.
What role do excipients play in ACTHREL?
Excipients are inactive ingredients used in formulation to enhance stability, solubility, and shelf life. For ACTHREL, excipients ensure the bioavailability of corticotropin, optimize product stability, and facilitate patient tolerability.
Existing excipient profile
- Preservatives: Benzyl alcohol (common in injectable formulations for antimicrobial preservation).
- Buffers: Phosphate buffers maintain pH stability.
- Stabilizers: Sugar alcohols or amino acids may stabilize peptide integrity.
- Vehicle components: Water for injection as the solvent.
These excipients maintain physico-chemical stability, prevent microbial contamination, and enable consistent dosing. They are selected based on compatibility with corticotropin and regulatory safety profiles.
How are excipient strategies evolving?
1. Optimization of excipient compositions
- Substituting benzyl alcohol with alternative preservatives (e.g., phenol or parabens) to reduce toxicity risks.
- Adjusting buffer systems to enhance peptide stability at varied temperatures.
- Incorporating osmotic agents to improve injection tolerability.
2. Development of preservative-free formulations
- Moving toward single-dose, preservative-free vials to align with safety concerns, especially for vulnerable populations.
- Using lyophilized powders reconstituted before administration, reducing preservative load.
3. Use of novel excipients
- Introducing excipients like sugars (lactose, sucrose) and amino acids (glycine) for stabilization.
- Utilizing surfactants or polymers (e.g., polyethylene glycol) to prevent aggregation and surface adsorption.
What are the commercial opportunities?
1. Formulation enhancements
- Developing preservative-free, high-concentration formulations could lead to smaller injection volumes, improving patient compliance.
- Creating multi-dose prefilled pens with integrated excipient stabilization reduces preparation time and contamination risk.
2. Generic and biosimilar development
- Reformulating existing ACTHREL with alternative excipients can facilitate bioequivalent generics.
- Innovation in excipient use opens pathways for biosimilars, provided regulatory pathways for peptide injections are clarified.
3. New indications through formulation
- Adjusting excipients to extend shelf life or improve stability at room temperature may expand supply chain flexibility.
- Improved stability profiles can enable use in regions with limited cold chain infrastructure.
4. Strategic partnerships
- Co-developing excipient technologies with excipient manufacturers (e.g., DisperSol Technologies, Croda) to customize formulations.
- Licensing novel stabilizers for peptide drugs to extend product lifecycle and market presence.
5. Regulatory incentives
- Patent protections on specific excipient formulations could provide exclusivity periods.
- Meeting strict safety profiles aligns with regulatory preferences, facilitating faster approvals.
Challenges and considerations
- Regulatory approval for excipient modifications requires comprehensive stability and safety data.
- Balancing excipient efficacy with tolerability, especially for sensitive patient populations.
- Navigating patent landscapes related to excipient innovations.
Key Takeaways
- Excipients in ACTHREL ensure stability, bioavailability, and safety for peptide delivery.
- Evolving strategies favor preservative-free, stable, patient-friendly formulations.
- Opportunities exist in developing high-concentration, multi-dose, or room-temperature-stable formulations.
- Reformulation to support generics or biosimilars can expand market access.
- Strategic alliances with excipient manufacturers and regulatory planning are essential for market differentiation.
FAQs
Q1: Can excipient modifications impact the efficacy of ACTHREL?
Yes, changes in excipient composition can alter peptide stability and bioavailability, necessitating thorough testing for efficacy and safety.
Q2: Are preservative-free formulations available for ACTHREL?
Preservative-free options are emerging, particularly in lyophilized forms reconstituted prior to use. The current marketed formulation contains benzyl alcohol.
Q3: What are the regulatory hurdles for excipient innovation?
Regulatory agencies require detailed stability, safety, and bioequivalence data to approve formulation changes, particularly for peptide injections.
Q4: How does excipient choice influence patient compliance?
Simpler formulations with fewer injections, smaller volumes, and reduced preservative load improve tolerability and adherence.
Q5: What market segments present the most opportunities?
Developing more stable, preservative-free, and patient-friendly formulations can expand use in pediatrics, geriatrics, and regions with limited cold chain infrastructure.
References
[1] Food and Drug Administration. (2021). Guidance for Industry: Peptide Drug Products. U.S. Department of Health & Human Services.
[2] European Medicines Agency. (2019). Guideline on the stability testing of pharmaceutical substances and products.
[3] Patel, R. K., & Patel, J. R. (2018). Excipients in peptide and protein formulation. International Journal of Pharmaceutics, 548(1), 408-425.
[4] U.S. Patent No. 10,887,540. (2021). Formulation of peptide therapeutics with stabilizing excipients.
