Govender, Sumentheran N., Stephanie Skoler, Robin A. Maguire, Laura Guichard, Pekka Lähteenmäki, Hlengiwe Vilakazi, Fridda Mapula, and Jasmine Rossier. "Evaluation of microbicide applicators to determine vaginal use in the Carraguard^® Phase 3 clinical trial."

Abstract

Currently, the only method employed to determine study gel use in a microbicide clinical trial is self-reporting. However, self-reporting is known to be an unreliable method of determining study gel use. A method was developed by the Population Council to apply a stain to study applicators producing a distinguishable pattern when the applicator has been vaginally inserted. When validated, it can be used in the current Carraguard^® Phase 3 clinical trial to test whether subjects are using the study gel as directed.

The method involves applying a Trypan blue stain (later changed to FD&C Blue No. 1 Granular Food Dye Powder) to the Micralax^®-type applicators used to deliver the study gel in Population Council-sponsored microbicide clinical trials. It was found that applicator tips that have been inserted into the vagina turn blue in a characteristic pattern when exposed to the stain. This effect is presumably due to the vaginal mucous that collects on the applicator tips. Lab staff at the Medunsa, University of Cape Town (UCT), and Medical Research Council (MRC) sites underwent a validation procedure to determine the accuracy and interpretation of the test. Validation kits using applicators inserted at the enrollment visit and placebos (n=100) were used in this process.

The validation procedure at the Medunsa and UCT sites made use of the Trypan blue stain while at the MRC the FD&C Blue No. 1 Granular Food Dye Powder was used. Results showed that 98% of the applicators were read correctly by technicians at the Medunsa site (n=4), 93% at UCT (n=4), and 95% at the MRC (n=2).

Results obtained indicate that staff members were proficient in the method and interpretation of the test. They were able to do this with 95%–96% (average) accuracy. All sites were thus able to proceed with the test within the context of the Phase 3 Carraguard trial. The test has been shown to be an inexpensive, easy, and reliable test to determine compliance of trial subjects and can be implemented in any research/laboratory setting. The validation procedure is carried out on an ongoing basis to make sure that the required standard of interpretation is met. This is the first biomarker with which to measure gel usage within the context of microbicide trials.

Track B & C: Adherence to Trial Procedures and Product Use
Monday, 24 April 2006, 1:30–3:00 pm

Microbicides 2006

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This page updated 3 April 2006

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