Evaluation of the integrity and tightness of packaging in the preparation of materials submitted to sterilization in an isolator by hydrogen peroxide vapors

Introduction:The integrity of the packaging after sterilization is essential to ensure satisfactory results in product/raw material sterility tests performed in isolators.The integrity of the packaging after exposure to hydrogen peroxide vapors in isolators is critical to maintaining the sterile barrier, but if the seal is compromised, the peroxide may contact the product/material and "mask" the results (false negatives).Objectives: To evaluate the integrity and seal of packaging exposed to high temperatures and to study its behavior when sterilized with hydrogen peroxide in an isolator.Methodology: Positive controls were used to evaluate the response to hydrogen peroxide, as well as negative controls that were not placed in the isolator.Six different experiments were conducted to evaluate different methods of packaging products into the insulator, as described below.In the first phase, the following scenario was tested: aluminum foil wrapping on glassware after sterilization in an oven at 270C.The following types of wrapping were evaluated: single wrapping, single wrapping with oven tape, double wrapping, and double wrapping with oven tape.The second phase tested the use of surgical paper on glassware after sterilization in an autoclave at 122C.Single and double wraps were evaluated, as well as glassware wrapped in autoclave tape with a layer of tissue paper and wipe paper.Since surgical paper cannot withstand the vacuum of the autoclave, an additional cover of a sterilizable plastic bag with plastic clip (pre-autoclaved) was used.Results: Aluminum foil and surgical paper packaging, in both single and double layer configurations, inside or outside the glassware, allowed hydrogen peroxide to penetrate and change the color of the indicator strips.On the other hand, sealing with a sterilizable transparent plastic bag and clamp prevented hydrogen peroxide vapors from penetrating, as the indicator strips inside and outside the tested material retained their original color, similar to the negative control. Conclusion:The results show that the choice of material and sealing method are critical factors in the effectiveness of the sterile barrier after exposure to hydrogen peroxide vapors, ensuring the integrity of materials undergoing sterilization processes in isolators.This eliminates potential false negatives in testing, improving test reliability and eliminating waste and non-conformance in the process.