Test Services

Sterility

BACKGROUND
Sterile: A state of being free of microorganisms. Results are expressed as “Negative at X days” for samples that are found to be free of microorganisms, or “Positive at X days” for samples that are found to contain microorganisms, where the “X” represents the number of days from 1 through 14 that the sample is incubated. The specification for sterility is “Negative at 14 days”.

OUR METHODOLOGY
DYNALABS employs the Membrane Filtration methodology for testing sterility of compounded medications. The test protocol is based on guidelines delineated in USP <71> Sterility Tests.

The sample is split into two equal portions and each portion is transferred into one of two 0.2um filter canisters. A vacuum is applied to the canisters and the aqueous portion of the medication is filtered away. The canisters are then washed 3 times to remove any residual drug and preservative. One canister is filled with Tryptocase Soy Broth (TSB) and incubated at 22.5 ± 2.5⁰C. This media is designed to grow aerobic microorganisms and fungi. The second canister is filled with Fluid Thioglycollate Medium (FTM) and incubated at 32.5 ± 2.5⁰C. This media is designed to facilitate the growth of anaerobic and facultative anaerobes. Both canisters are incubated for 14 days. For turbid samples, a portion of the incubated media is transferred to fresh media on the 14th day and then incubated an additional 4 days.

Negative controls are run at the beginning and end of each batch of samples tested. All control and sample canisters are inspected every day, and the results updated according to the inspection findings. If any sample canister shows signs of growth the customer is notified immediately.

FORMS TESTED
All Sterile Forms