T/ZGXX 0004-2022 Evaluation method for the long-lasting antibacterial effect of cosmetics and personal care products

Scope

Main Technical Content: 11. Bacteriostatic Effect Test 11.1 Inoculation of Samples - Each 2 samples or 2 control samples are considered a group. - Two groups of control samples and one group of samples are placed in three empty sterile Petri dishes, and 0.25 mL of test bacterial suspension (9) is added to each dish. The test bacterial suspension should be evenly spread on the samples and control samples. - The two groups of control samples are used for immediate elution and testing after inoculation, and for elution and testing after culturing for a certain period (t hours). The one group of samples is used for elution and testing after culturing for a certain period (t hours). - The bacterial culturing time t should be no less than 18 hours, and the number of recovered colonies from the control samples immediately after elution should be within the range of (1×104 CFU/group) to (9×104 CFU/group). - Use sterile forceps to pick up the just-inoculated control samples and place them in a homogenizer bag containing 10 mL of bacterial elution solution (7.8). Shake the samples in the homogenizer for 1 minute to elute the bacteria from the carrier. If no homogenizer is available, transfer the control samples to a 100 mL sterile Erlenmeyer flask containing 10 mL of bacterial elution solution (7.8) and shake them by hand for 30 seconds (with an amplitude of about 30 cm) to elute the bacteria from the carrier. The laboratory can adjust the amount of bacterial elution solution (7.8) to 20 mL according to actual needs. - Cultivation and elution of inoculated samples - Place the two sterile Petri dishes containing the inoculated test bacterial suspension carriers (one with 2 samples and one with 2 control samples) under Petri dish lids and seal with cling film to prevent evaporation of the liquid on the carriers. Cultivate in a constant temperature and humidity incubator (6.1) for t hours at a relative humidity of no less than 85% and a cul

Development Information

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