• 목록

Yong-Hyun Cho*, Jun-Hyung Park, Ki-Young Hwang, Hyung-woo Kim, Hong-Jae Lee, Hyun-Ju Kim

Pet center, Nuclear Medicine, Seoul National University Hospital, Seoul, Korea

Purpose

The radiopharmaceuticals are routinely injected to blood vessel for acquiring PET image. For this reason, It is imperative that they undergo strict quality control measures. Especially, Sterility test is more important than any other quality control procedures. Nevertheless, Due to radiation exposure and longer test time than half-lives of radionuclides, sterility test must be performed on a post hoc basis. According to the FDA guideline, It requires filter integrity test used in the processing of sterile solutions. Among several methods, we can decide to use bubble point test. This test will detect damaged filter membranes, ineffective seals, system leaks and so on.

Materials and Methods

We usually use vented GS-filters (Millipore co., USA) which are sterilizing-grade (0.22 um pore size) and are placed upper site on product vial. To prevent emitting radiation, a product vial is enveloped in the lead vial shield which has lead glass. During the synthesis of 18F-FDG, all of the solutions are passed through from ion exchange column, Sep-Paks, filter, to product vial by gas. Solutions wet the membrane in filter and then go into the product vial. By all synthesis steps have finished, we can observe the presence of the bubbles in the product vial.

Results

Since we have started this study, we have never found any bubbles in the product vial. Because the maximum pressure intensity of the filter which has set by manufacturer is up to 5 bars, but helium gas pressure is up to 1 bar in our module system. So, we can make 5 bars pressure using helium gas bombe and increase pressure up to 5 bars step by step. However, it does not happen to anything in vial.

Conclusion

The most widely used non-destructive filter integrity test is the bubble point test. It is a sensitive, visual technique. It must be routinely performed for radiopharmaceuticals sterility. In accordance with each test report, operators can decide whether it could dispense or not.

Key words: filter integrity test, bubble point test, non-destructive test, sterility, 0.22 um pore size.