To maintain equivalence with clinical use in hospital pharmacy, ISO 5 air conditions were used in this study and only one person for each group performed the testing without assistance. Furthermore, approximately a third of the tested Equashield® syringes and adapters were old products with expired use-dates. The tested vials were incubated for 2 days at 30°-35°C after the 9 days of testing and examined to demonstrate the ability of the Equashield® CSTD to prevent vial contamination during 7 days of use.
The results of the study confirmed that despite the extreme-use clinical conditions, the Equashield® CSTD prevented the microbial contamination of media-filled vials, which are more sensitive to contamination than drugs. The penetration of even one microorganism is suficient to create full contamination, and although the chances of bacteria survival and growth inside a hazardous drug vial are very slim, the media-filled vials used in the current study provided ample conditions for their multiplication and spreading.
To create even more extreme conditions, the vials in the current study were accessed up to 10 and 7 times during 7 days, whereas vials in previous studies3,4 were accessed only 5 times. Since the ability of a single connector to prevent contamination is naturally decreased with every additional connection and access, the number of connections gains increased significance in view of this non-linearly growing potential of contamination.
The repeated inoculation of the membrane with vivid bacteria before each of the vial accesses poses an extreme challenge to this primary microbial barrier; a challenge that does not exist (to such an extent) in a hospital routine setting, and that was also not included in the referenced studies3,4.
Without the special mechanisms and design features incorporated into the Equashield® connectors, the membrane alone would not be capable of such barrier performance. In fact, the doublemembrane connectors with their coring-free needles, special materials, and sequential guiding mechanisms, are responsible for creating the optimal conditions for satisfactory contamination prevention.
During the half hour that the bacteria were left to grow and settle on the membrane, the risk of them entering and settling in the openings or surface irregularities in the membrane, and subsequently moving into the vial or being moved by the penetrating needle, was obviously increased considerably in this study. In comparison, the FDA5,7 requires a minimum of only 1 minute for challenging microbial barriers. The ½ hour challenge time was chosen since at longer challenge the bacteria dries and becomes inactive.
The extreme conditions included the use of a significant number of Equashield® syringes and adapters that were old products with expired use-dates, whereby the sterility of their packaging may have been compromised, as often occurs with old products, and therefore the risk of contamination was much greater than expected from new products that were more recently packaged.
Unlike the conditions in many privileged hospital pharmacies and in previous studies3,4, no cleanroom was used in this study and the laminar flow hood had an open front without the glass screen (which normally improves the isolation of the hood). To maintain equivalence with routine working procedures and conditions in a hospital pharmacy, only one person performed the testing without assistance, and the device packages were opened inside the hood. Furthermore, unlike experienced personnel in hospital pharmacies and previous studies3,4, the operators were not proficient in using Equashield® and only received basic training at the commencement of the study.
The two types of vial accesses, namely: the spiking of the Vial Adaptor onto the vial and the access to the Vial Adaptor with the syringes, were purposely separated in this study. After spiking, the vials were incubated 2 days long and observed for turbidity before syringe accessing began. Both types of vial accesses were effective in preventing microbial ingress.
Furthermore, larger needles are known to cause greater damage and increase leak potential to barrier membranes than thinner needles; therefore Equashield® syringes with the larger needles were used in this study.
Thus, it could be argued that the current study not only reaffirms previous studies results, it also indicates that the solution in the vials remained uncontaminated when using the Equashield® CSTD in even more extreme conditions than may exist in hospital pharmacies, suggesting the possibility of practical benefit from the prevention of the microbial ingress feature, especially for single-use or nonpreserved drugs.
The current study unequivocally demonstrated that Equashield® CSTD is capable of preventing the microbial ingress and contamination of drugs over 7 days of use, which makes it a true CSTD, compliant with both aspects of NIOSH’s definitions2, namely: mechanically prohibiting the transfer of environmental contaminants into the system and the escape of hazardous drug or vapor concentrations outside the system.
Additionally, the standard disinfection procedure using IPA pads on Equashield® access ports was identified as adequate in preventing microbial ingress.
This ability of the CSTD, to provide extended microbial ingress prevention in extreme clinical conditions over a 7 day period, suggests improved patient protection in view of USP Chapter 7971 standards that currently limit the use of single-use non-preserved drugs to up to 6 hours in ISO class 5 air conditions.
The purpose of this research is to demonstrate the potential use of the Equashield Closed System Device. Its publication does not constitute and must not be construed as promotion or advice to deviate from, alter or otherwise exceed the guidelines, rules and standard related to aseptic preparations and techniques, or in any way deviate, alter or exceed the USE DATE or SHELF LIFE of the drugs. For any modification a user must comply with required steps and measures to change the established guidelines, rules and standard related to aseptic preparations and techniques, such as the procedural changes described in USP 797.
