ASTM E1173-15. Standard Test Method for Evaluation of Preoperative, Precatheterization or Preinjection Skin Preparations.

Test with the Certificate of Good Laboratory Practices (GLPs).

The procedure described by the ASTM E1173 standard is designed to measure the reduction of the skin microflora after application of the test product in different areas of the skin of volunteers. At IVAMI this test is carried out with 18 to 24 volunteers. At least 14 days before conducting the test, volunteers must refrain from the use of topical and oral antimicrobials and, 24 hours before the start of the test, they must refrain from showering or bathing. The antimicrobial activity of preoperative, vascular precatheterization, or preinjection skin preparations is measured by comparing the microbial counts obtained at one or more time intervals after application of a test formulation to specific skin areas, with the counts obtained in the same area of ​​skin before application of the formulation. As a result of the test, it is determined whether the difference between the counts obtained before and after the treatment is statistically significant. Parallel to the test with the test product, the procedure is carried out with a reference product, as a control.

Depending on the intended use of the product to be evaluated, the areas of the skin recommended for the test vary. For preoperative and pre-catheterization skin preparations both a wet area and a dry area should be analyzed, while for pre-injection preparations, only a dry area should be analyzed. Recommended skin areas for testing with preoperative skin preparations are the groin (as a wet area) and the abdomen (as a dry area); while for pre-catheterization preparations, the inguinal region (wet area), and the subclavian region or the median ulnar region of the arm (dry areas) are recommended; and for pre-injection skin preparations the median ulnar region of the arm (dry area) is recommended.

Depending on the intended use of the product, the test times are also different. In addition, when taking a sample of skin not treated with the test product, for preoperative skin preparations samples must be taken a minimum of three times after application of the test preparation, and the recommended times are 10 min, 30 min and 6 hours. For pre-catheterization preparations, samples must also be taken a minimum of 3 times and the recommended times in this case with an immediate time (to choose between 30 seconds and 10 min), 12 hours and 24 hours after the treatment. Finally, for pre-injection skin preparations only a sampling time is required, 30 seconds after treatment.

At IVAMI, currently only the test for pre-injection skin preparations is carried out. For this test, in our laboratory, the control procedure performed in parallel with the test is carried out by impregnating a medical gauze with 3 mL of 60% propanol-1 and applying it with friction with 5 movements from top to bottom and then with 5 movements from right to left, covering the entire test area. The frictions are repeated for 30 seconds.