Cagrilintide: form, reconstitution and storage

Form and specification

Cagrilintide is supplied as a white lyophilised (freeze-dried) powder in a glass vial, nominal content 10 mg, stated purity ≥99% (HPLC). The lyophilisate is the most stable form of the peptide: in dry form and under proper storage it retains its integrity for an extended period.

Reconstitution (chemistry)

To bring it into solution, laboratory practice uses bacteriostatic water (water for injection with 0.9% benzyl alcohol) or sterile water. The solvent is added slowly, directing the stream against the vial wall rather than directly onto the peptide pellet, to avoid foaming and mechanical denaturation. The vial is not shaken — it is swirled or left to dissolve completely. The solvent volume is chosen according to the desired working-solution concentration; the benzyl alcohol in bacteriostatic water has mild antimicrobial activity that extends the usable life of a repeatedly accessed vial in research settings.

Storage

The lyophilised material is stored refrigerated (2–8 °C) for the medium term or at –20 °C and below for long-term storage; brief exposure to room temperature during transport is acceptable. After reconstitution the solution is kept at 2–8 °C, protected from light and from repeated freeze-thaw cycles, which degrade the peptide chain.

Stability

Peptides in solution hydrolyse and aggregate faster than in dry form; acylation and the proline substitutions increase cagrilintide's resistance to aggregation but do not remove the need for a cold chain. A solution that has become cloudy, changed colour, or contains visible particles is not suitable for research.

Laboratory handling

Work under aseptic conditions, use sterile tips and syringes, and record the batch/lot and reconstitution date. Avoid direct light and repeated puncturing of the stopper.

Research applications

In research, cagrilintide is used as a tool agonist of the amylin/calcitonin receptors — to study satiety signalling, energy balance, and in combination models with GLP-1 agonists. The material is intended exclusively for laboratory research (RUO) and not for use in humans or animals for therapeutic purposes.