Can Depotrust (Medroxyprogesterone) Be Mixed with Sterile Water?
No, Depotrust (medroxyprogesterone acetate injectable suspension) should never be mixed with sterile water or any other diluent—it is supplied as a ready-to-use sterile aqueous suspension that must be administered directly as formulated.
Formulation and Administration
The FDA-approved formulation is specifically designed as a sterile aqueous suspension containing medroxyprogesterone acetate 150 mg/mL with specific excipients including polyethylene glycol 3350, polysorbate 80, sodium chloride, methylparaben, propylparaben, and water for injection 1. This suspension is:
- Pre-formulated and ready to use without any dilution or reconstitution 1
- Administered intramuscularly at 150 mg every 13 weeks or subcutaneously at 104 mg every 13 weeks 2, 3
- A suspension, not a solution, meaning the active drug particles are suspended in the vehicle and must remain in this specific formulation for proper absorption and pharmacokinetics 4
Why Dilution Is Contraindicated
Diluting or mixing medroxyprogesterone acetate suspension with sterile water would fundamentally alter the drug's pharmacokinetic properties and render it ineffective. The formulation is engineered as an aqueous suspension that releases slowly from the injection site over approximately 3 months, with medroxyprogesterone acetate concentrations plateauing at about 1.0 ng/mL for three months before gradually declining 4.
Key pharmacokinetic considerations:
- The suspension achieves detectable serum concentrations within 30 minutes and maintains therapeutic levels for 120-200 days after a single injection 1, 4
- The specific excipients (polyethylene glycol, polysorbate 80) are critical for maintaining the suspension and controlling drug release 1
- Adding water would disrupt the suspension, potentially causing precipitation or altered absorption kinetics
Critical Administration Points
The product must be shaken vigorously before administration to ensure uniform suspension, but no dilution should occur 1. The injection can be given:
- Up to 2 weeks late (15 weeks from last injection) without requiring backup contraception 2, 3
- Either as provider-administered or self-administered subcutaneous formulation 2, 3
Common Pitfall to Avoid
Never attempt to reconstitute, dilute, or mix depot medroxyprogesterone acetate with any substance. Unlike some other injectable medications that require reconstitution, this product is supplied ready-to-use. Any manipulation of the formulation beyond vigorous shaking could compromise contraceptive efficacy and patient safety 1.