ICU M ED IC A L SU P P O RT ING INF O R M AT IO N

ChemoLock™ Closed System Transfer Device (CSTD)
Microbial Ingress Study
Report of a study commissioned by ICU Medical, Inc. and conducted by AAIPharma Services Corp.

Background
The ChemoLock CSTD is a needlefree closed system drug transfer device (CSTD) that meets the definition of a CSTD thatis recognized by USP <800> as “a drug transfer device that mechanically prohibits the transfer of environmental
contaminants into the system, and the escape of the hazardous drug or vapor concentrations outside the system.”1,2
To validate a CSTD’s ability to “mechanically prohibit the transfer of environmental contaminants into the system,”
Microbial Ingress test methods have been developed and commissioned by ICU Medical, Inc.
The US Food and Drug Administration (FDA) has issued a guidance document related to microbial ingress testing, as partof the premarket clearance 510(k) process for intravascular administration sets.3
This guidance document serves to assist manufacturers in the development of appropriate test methods, types ofmicroorganisms to consider in the study, and sampling size. Microbial Ingress test results are also included in thedocumentation submitted to the FDA in order to obtain 510(k) clearance. The ChemoLock CSTD was originally cleared
under K131549 with the following Indications for Use: The ChemoLock Closed System Drug Transfer Device prevents thetransfer of environmental contaminants, including bacterial and airborne contaminants, into the system and the escapeof drug or vapor concentrations outside the system. The ChemoLock CSTD was subsequently cleared as part of theDiana™ Medication Transfer Set under K170110 which included the data outlined in this paper.4

Introduction
The purpose of this microbial ingress study was to evaluate the ChemoLock CSTD’s ability to prevent microbial contaminationof the system during a worst-case, simulated use test model. The test model included the artificial contamination of theChemoLock port, followed by a decontamination process and multiple activations over a 7-day use life.
This white paper describes the methods including the types of challenge microorganisms used, the microbial recovery
methods, sample size, controls, procedures including the inoculation methods, the environmental conditions, thevalidation methods, and the rationales used for these choices.5Methods
Organisms (Four Bacterial Strains)
Organisms chosen for this study include 2 gram-negative and 2 gram-positive organisms, which represent normal
microbiological flora found in a clinical setting. The target concentration of 1-5x103 represents a higher-than-expected
microbial contamination load during worst-case clinical use.
> Staphylococcus aureus (ATCC 6538)> Pseudomonas aeruginosa (ATCC 9027)> Staphylococcus epidermidis (ATCC 12228)> Klebsiella pneumoniae (ATCC 4352)

Microbial Recovery Study
The microbial recovery study is designed to demonstrate the suitability of the test method by showing microorganisms
can be successfully recovered by following the test method in the protocol. This phase of the study was done following
the below methods.
The ChemoLock port septum was inoculated in duplicate with an appropriate volume of inoculum to yield one 5x103
colony-forming units (CFUs) of each test organism, listed in the report under Organisms, and then allowed to dry for
1 minute at ambient conditions. After drying, the port was placed in 10 mL of sterile 0.9% sodium chloride and was mixedusing a vortex mixer. The positive control was prepared by inoculating a 10 mL volume of 0.9% sodium chloride with thesame inoculum volume used to inoculate the port, followed by 1 mL aliquots being plated to trypticase soy agar (TSA) andincubated at 30–35°C for 1–2 days.
After incubation, the lab performed the colony counts to determine the percent recovery asPercent recovery =CFU recovery fluid
CFU inoculum count

X 100

The acceptance criteria of the percent recovery must be greater than 70%. As seen in Table 1, all microbial recovery testing
meets this criterion.
Table 1. Microbial Recovery Studies Results

Recovery(CFU/Device)

Positive Control
Recovery Average(CFU)

Staphylococcus aureus

1.9 x 103

Staphylococcus epidermidis

3Percent
RecoveryMeetsCriteria

2.0 x 103

95%

Yes

2.0 x 102.0 x 103

100%

Yes

Pseudomonas aeruginosa

1.4 x 103

1.3 x 103

108%

Yes

Klebsiella pneumoniae

1.9 x 103

2.4 x 103

79%

Yes

Test Organism

Sample Size
The study evaluated six replicate ChemoLock CSTD ports that were inoculated with 4 separate organisms and accessed
70 times. The number of activations represents the worst-case clinical use and is in alignment of the FDA’s requirements
for the microbial recovery of medical devices.

Inoculum Concentration
1-5x103 colony-forming units (CFUs) for each activation

Procedure
Each ChemoLock port septum was inoculated with the test organism before each activation. The port was then disinfectedwith a 70% isopropyl alcohol (IPA) prep pad using an aggressive circular motion for not less than 3 seconds and allowedto dry. The port was then activated using the ChemoLock injector syringe assembly where 10 cc of normal saline wastransferred through the port, and the transferred saline was collected and filtered through a 0.45 µm cellulose nitrate
filter. The filter was rinsed with 100 mL of 0.9% saline, transferred to a solidified plate of TSA, incubated for a minimum of
48 hours at 30–35°C, and finally examined for growth.
This process was repeated for a total of 10 artificial contaminations, followed by an activation each day for 7 days. The total
number of artificial contamination and fluid transfer events was 70.

Positive Controls
The positive controls were performed in duplicate for each organism by performing the activation and testing procedure
above without the 70% IPA disinfection step.

Negative Controls
Negative controls were performed following the same procedure as the test samples with the omission of the microbial
inoculation procedure.

Results
There was no microbial recovery on the negative controls. Results can be referenced in Tables 2–5 below.

Table 2. Staphylococcus Aureus Microbial Ingress Results

Replicate (CFU/filter)

Activation

Table 3. Staphylococcus Epidermidis Microbial Ingress Results

123456Inoculum
Verification(CFU/Device)

Replicate (CFU/filter)

Activation

123456Inoculum
Verification(CFU/Device)

DAY 1

1–100000001.1 X 103

DAY 1

1–10

0000001.2 X 103

DAY 2

11–20

0000001.7 X 103

DAY 2

11–20

0000001.7 X 103

DAY 3

21–30

00000031.4 X 10

DAY 3

21–30

000000

1.4 X 103

DAY 4

31–40

0000001.2 X 103

DAY 4

31–40

0000002.4 X 103

DAY 5

41–50

0000001.2 X 103

DAY 541–50

0000001.4 X 103

DAY 651–60

00000031.2 X 10

DAY 651–60

0000001.1 X 103

DAY 7

61–70

0000001.1 X 103

DAY 7

61–70

0000002.6 X 103

Positive Control Replicate 1 (CFU/Filter)

39

Positive Control Replicate 1 (CFU/Filter)0

Positive Control Replicate 2 (CFU/Filter)3

Positive Control Replicate 2 (CFU/Filter)

3

Table 4. Pseudomonas Aeruginosa Microbial Ingress Results

Replicate (CFU/filter)

Activation

Table 5. Klebsiella Pneumoniae Microbial Ingress Results

123456Inoculum
Verification(CFU/Device)

Replicate (CFU/filter)

Activation

123456Inoculum
Verification(CFU/Device)

DAY 1

1–10

000000

1.9 X 103

DAY 1

1–10

0000001.3 X 103

DAY 2

11–20

00000031.5 X 10

DAY 2

11–20

000000

1.1 X 103

DAY 3

21–30

000000

1.9 X 103

DAY 3

21–30

0000001.1 X 103

DAY 4

31–40

0000001.7 X 103

DAY 431–40000000

1.5 X 103

DAY 5

41–50

00000031.7 X 10

DAY 5

41–50

0000001.3 X 103

DAY 6

51–60

0000001.2 X 103

DAY 6

51–60

000000

1.1 X 103

DAY 7

61–70

000000

1.1 X 103

DAY 7

61–70

000000

4.2 X 103

Positive Control Replicate 1 (CFU/Filter)

6

Positive Control Replicate 1 (CFU/Filter)

8

Positive Control Replicate 2 (CFU/Filter)

6

Positive Control Replicate 2 (CFU/Filter)

24

Conclusion
Based on the results of the microbial ingress testing as reported above, it is determined that the ChemoLock systemmeets established criteria for microbial ingress. As part of the devices 510(k) clearance, data was provided to demonstrate
the ChemoLock system’s ability to prevent the transfer of environmental contaminants, including bacterial and airborne
concentrations, into the system as reflected in the devices Indications for Use statement.

References
1.

The United States Pharmacopeial Convention. USP General Chapter <800> Hazardous Drugs – Handling in Healthcare Settings. Chapter 14:
Administering. 20172.

National Institute for Occupational Safety and Health (NIOSH): A Performance Test Protocol for Closed System Transfer Devices Used During
Pharmacy Compounding and Administration of Hazardous Drugs. NIOSH Docket Number 288-A

3.

Guidance for Industry and FDA Staff: Intravascular Administration Sets Premarket Notification Submissions [510(k)], US Department of Healthand Human Services, Food and Drug Administration, 2008, Rockville, MD. http://www.fda.gov/downloads/MedicalDevices/
DeviceRegulationandGuidance/GuidanceDocuments/ucm070850.pdf

4.

ICU Medical ChemoLock 510(k) Summaries K131549 and K170110

5.

AAIPharma, Microbial Ingress Study for ChemoLock Connector Devices, August 2014

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