How to Reconstitute Retatrutide 10 mg: Step-by-Step Guide
EXOMA Scientific Team · Publicado el · Actualizado el
Technical procedure for reconstituting a lyophilized vial of Retatrutide 10 mg with bacteriostatic water while maintaining sterility and stability.
Before starting
This guide describes the standard procedure for reconstituting a lyophilized vial of Retatrutide 10 mg with use intended for research.
Materials needed
- 1 vial of Retatrutide 10 mg lyophilized
- 1 vial of bacteriostatic water 10 mL
- 1 syringe of 3 mL with a 21G needle (to draw diluent)
- U-100 insulin syringes (for dosing)
- Sterile cotton with 70% isopropanol
- Disinfected work surface
Step 1: Prepare the surface
Clean the work surface with 70% isopropyl alcohol. Wash your hands for 20 seconds with antibacterial soap and let air dry.
Step 2: Disinfect the rubber stoppers
Rub the rubber cap of the Retatrutide vial and of the bacteriostatic water with a cotton swab impregnated with 70% isopropanol. Wait 15 seconds for it to evaporate completely before puncturing.
Step 3: Calculate the volume
The choice of diluent volume determines the final concentration:
| Diluyente añadido | Concentración resultante | Dosis 2 mg |
|---|---|---|
| 1 mL | 10 mg/mL | 20 unidades U-100 |
| 2 mL | 5 mg/mL | 40 unidades U-100 |
| 2.5 mL | 4 mg/mL | 50 unidades U-100 |
The option 2 mL → 5 mg/mL is the most used in the literature because it provides convenient withdrawal volumes in an insulin syringe.
Step 4: Draw up the bacteriostatic water
With the 3 mL syringe, draw the chosen volume (2 mL in this example). Keep the needle below the liquid level to avoid bubbles.
Step 5: Inject the diluent slowly
Insert the needle into the Retatrutide vial at a 45° angle. Let the water run down the inner wall of the vial, do not inject it directly onto the powder. This preserves the structural integrity of the peptide.
Step 6: Dissolve without shaking
Do not shake the vial. Swirl it gently between the palms for 30-60 seconds until the powder is completely dissolved. The solution should look clear and free of particles.
If particles remain or the solution looks cloudy, discard the vial.
Step 7: Label and store
Note on a label:
- Concentration (e.g. 5 mg/mL)
- Reconstitution date
- Diluent used (bacteriostatic water)
Store refrigerated 2-8°C. The stability of the reconstituted compound is approximately 28 days at this temperature.
Common errors
| Error | Consecuencia |
|---|---|
| Injecting water at high pressure onto the powder | Partial denaturation of the peptide |
| Shake the vial vigorously | Formación de espuma, pérdida de actividad |
| Usar agua estéril sin conservante | Contaminación bacteriana en uso múltiple |
| Not disinfecting the stopper before each withdrawal | Vial contamination |
Dose calculation
With a concentration of 5 mg/mL (U-100 syringe, 100 units = 1 mL):
- 2 mg = 40 units
- 4 mg = 80 units
- 5 mg = 100 unidades (la mitad del vial)
El vial de 10 mg reconstituido en 2 mL contiene 200 unidades U-100 en total. Una jeringa de insulina de 100 unidades extrae como máximo 1 mL, es decir 5 mg, así que el vial rinde dos extracciones completas.
Post-reconstitution stability
| Condición | Stability |
|---|---|
| 2-8°C (refrigerador) | 28 days |
| 25°C (ambiente) | No recomendado |
| -20°C (congelador) | 60 días, aceptar 1 ciclo congelación |
References
- USP <797> Pharmaceutical Compounding—Sterile Preparations.
- Stability data on file, Eli Lilly LY3437943 development program.
- Wang W. Lyophilization and development of solid protein pharmaceuticals. Int J Pharm 2000;203:1-60.