Sterility Testing

As per USP , all high-risk level compounded sterile preparations (CSPs) that are prepared in groups of more than 25 identical individual single-dose packages (e.g. ampules, bags, syringes, vials) or in multiple-dose vials (MDVs) for administration to multiple patients or that are exposed longer than 12 hours at 2-8°C and longer than 6 hours at warmer than 8°C before they are sterilized shall meet the sterility test before they are dispensed or administered.

Sterility testing of CSPs is a part of the quality control testing required to ensure that products have been prepared using strict aseptic process. It is essential to use adequate sample sizes and sample volumes to allow for the results to be representative of the entire batch.

For test samples containing a penicillin or cephalosporin, actions must be taken to inactivate the antibiotic. If using the direct inoculation method, the addition of the appropriate beta-lactamases to the medium should be done, or if the membrane filtration method is used, the rinse solution. Solutions containing a preservative should either be neutralized or diluted out before testing.

Table 1. Minimum Quantity to be used for Each Medium