Sterilization of Udder Injectors
Primary Packaging solutions for pharmaceutical products come in large variety of material and design. With elmplastic, we service a wide range of so called injectors and applicators with multiple volumes. Our products are manufactured in clean room environment. For particular use cases, it is required to sterilize the products for appropriate post processing.
For example, for Udder injectors, which are veterinary medical devices specifically designed for treating animal udders, which are particularly sensitive anatomical areas. These devices are commonly used for administering antibiotics, necessitating the use of sterile application systems to preserve medication efficacy. Additionally, a contaminated environment raises the risk of developing and spreading antibiotic-resistant bacteria, making the sterility of these devices critically important. Manufacturing under cleanroom conditions alone cannot ensure sterility; it is equally important to produce these devices with minimal microbiological contamination to facilitate subsequent sterilization using the lowest effective irradiation dose. This approach is vital, as irradiation may degrade polymer materials and potentially compromise product functionality.
According to established guidelines, the standard sterilization procedure requires a minimum irradiation dose of 25 kGy (VDmax25). To ensure uniform distribution of this minimum dose across all products within a pallet or similar container, higher doses are often necessary, possibly exceeding 50 kGy, to compensate for dose distribution variability. However, such elevated doses can significantly degrade polymer components. To address this issue, efforts focus on reducing the radiation dose while achieving effective sterilization. The VDmax15 method, outlined in EN ISO 11137-2, allows for sterilization at a lower minimum dose of 15 kGy, provided that the product's microbial bioburden is sufficiently low. This method is applicable for products with an average microbial load of no more than 1.5 colony-forming units (cfu) per unit.
Our sterilization process at elmplastic is validated in accordance to this standard and a true product benefit.
Given that irradiation may induce chemical degradation and produce pyrolysis products, a comparative chemical analysis was performed on both irradiated and non-irradiated udder injectors. The injectors were subjected to a worst-case irradiation dose of 35 kGy, which represents the maximum dose established during dose mapping to ensure that each product within a pallet receives at least 15 kGy.
The analysis aimed to identify and quantify organic extractables in both irradiated and non-irradiated injectors. Results indicated that irradiation caused chemical alterations in the polymer components, with a notable degradation of erucamide—a commonly used slip agent—likely due to oxidation processes intensified by irradiation.
Additionally,degradation of unsaturated hydrocarbons such as 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, and 1-hexacosene was observed.
Furthermore, the antioxidant stabilizers octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (Irganox 1076) and tris(2,4-di-tert-butylphenyl)phosphite (Irgafos 168) were found to be completely degraded. This degradation led to the formation of multiple oxidation products, including 1,3-di-tert-butylbenzene, 2,4-di-tert-butylphenol, and tris(2,4-di-tert-butylphenyl)phosphate.
These findings imply that irradiation may adversely impact the long-term stability of the injectors, potentially compromising essential properties such as the sliding behavior of the plunger within the injector body. Consequently, the results underscore the critical need for manufacturing under strict cleanroom conditions to minimize initial bioburden and enable sterilization at the lowest effective irradiation dose, thereby reducing the risk of polymer degradation.
Our customers trust in elmplastic is proof of our competence and product quality – from plastic manufacturing to post processing as per customer requirements.
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