ARA-290: form, reconstitution and storage

Supplied form

ARA-290 (cibinetide) is supplied as a sterile lyophilized powder, nominally 10 mg per vial, purity typically > 98% (HPLC). The powder is white to off-white; a thin layer of pellet at the bottom of the vial is normal for a lyophilizate. The material is intended solely for laboratory research (RUO).

Reconstitution

For research reconstitution, bacteriostatic water for injection (water with 0.9% benzyl alcohol) is used — the preservative extends the shelf-life of the solution under refrigeration. The diluent volume is chosen for the desired working concentration (for example, 1–2 mL into a 10 mg vial gives 5–10 mg/mL). The diluent is added slowly down the inner wall of the vial, directing the stream onto the glass rather than the pellet. The vial is not shaken — it is swirled or left to dissolve fully. Shaking creates shear stress and foam, which promote peptide denaturation and aggregation.

Storage

The lyophilized powder is the most stable form: store at −20 °C for long-term storage, or refrigerated, protected from light and moisture. The reconstituted solution is kept at 2–8 °C. Because aqueous peptide solutions have limited stability, for longer storage the solution is aliquoted into sterile tubes and frozen, minimizing the number of freeze-thaw cycles — each cycle reduces the yield of intact peptide.

Stability & handling

Peptides with an N-terminal pyroglutamate (like ARA-290) are more resistant to aminopeptidase degradation, but aqueous solutions are still sensitive to heat, oxidation and microbial contamination. Work is done under aseptic conditions, avoiding repeated puncturing of the stopper and logging the reconstitution date. Frozen aliquots are thawed slowly and brought to room temperature before use.

Research applications

In the laboratory, ARA-290 is used as a selective ligand of the innate repair receptor (IRR) to study anti-inflammatory and neuro-regenerative signalling pathways — in vitro in cell cultures and in vivo in models of neuropathy, ischemia and inflammation. The material is not intended for human or animal medical use.