This guide is for informational and educational purposes only. It does not constitute medical advice. Consult a licensed healthcare provider before using any medical supplies.
What is Reconstitution?
Reconstitution is the process of adding a diluent (solvent) to a lyophilized (freeze-dried) compound to return it to a liquid state. The most common diluent used in reconstitution is bacteriostatic water (BAC water) - sterile water preserved with 0.9% benzyl alcohol.
This process requires precision. The amount of diluent added determines the concentration of the final solution, and contamination during reconstitution can compromise the entire compound. Proper technique is not optional.
What You Need
- Bacteriostatic water (USP-grade, from an FDA-registered 503B facility)
- Mixing needle (18G x 1.5" recommended for drawing)
- Insulin syringe (29G x 0.5" for final administration)
- Sterile alcohol swabs (70% isopropyl)
- Clean, flat workspace
- Sharps disposal container
Step 1: Prepare Your Workspace
Choose a clean, flat surface in a low-traffic area away from open windows, fans, or air vents. Wipe the surface with 70% isopropyl alcohol and allow it to air-dry completely. Lay out all supplies before beginning - opening packages during the procedure increases contamination risk.
Step 2: Hand Hygiene
Wash hands thoroughly with soap and warm water for at least 20 seconds. Dry with a clean, lint-free towel. This is not a suggestion - it is the single most effective contamination prevention measure.
Step 3: Prepare Both Vials
Remove the flip-top caps from both the BAC water vial and the compound vial. Do not remove the aluminum crimp seals. Swab both rubber stoppers with separate alcohol pads, using firm circular pressure from center to edge. Allow 30 seconds to air-dry. Do not blow on them.
Step 4: Draw the BAC Water
Attach an 18G mixing needle to a syringe. Pull back the plunger to draw air equal to the volume of BAC water you need. Insert the needle through the center of the BAC water vial stopper. Inject the air (equalizes pressure), invert the vial, and draw the desired volume. Tap the barrel to dislodge air bubbles, push them back into the vial, then withdraw the needle.
Step 5: Add to the Compound
Insert the needle through the compound vial stopper. Inject the BAC water slowly, aiming the stream against the glass wall of the vial - not directly onto the lyophilized cake. This prevents damage to the compound structure.
Step 6: Mix Gently
Swirl the vial gently between your fingers. Never shake it. Shaking can denature proteins and damage the compound. The solution should become clear within a few minutes. If particulate matter remains after 5 minutes of gentle swirling, do not use.
Step 7: Calculate Your Concentration
The concentration of your reconstituted solution depends on the amount of compound and the volume of diluent added.
Formula: Compound amount (mg) / BAC water volume (mL) = Concentration (mg/mL)
Example: 5mg compound + 2mL BAC water = 2.5mg/mL
Use our Reconstitution Calculator to compute your specific concentration and dosing volumes.
Step 8: Storage
Store the reconstituted solution refrigerated at 2-8C (36-46F). Use within 28 days of reconstitution. Always swab the stopper before each subsequent draw. Mark the date of reconstitution on the vial.
Step 9: Disposal
Place all used needles and syringes directly into a sharps container. Never recap needles. When the container reaches the fill line, seal it and dispose per local guidelines.
Common Mistakes
- Shaking the vial - Always swirl, never shake
- Skipping the alcohol swab - Swab every stopper, every time
- Reusing needles - One needle, one use
- Drawing with an insulin syringe - Use an 18G mixing needle to draw, then transfer
- Storing at room temperature - Reconstituted solutions must be refrigerated