Integrity performance assessment of a closed system transfer device syringe adaptor lock as a terminal closure for Luer-Lock syringes.

OBJECTIVES: To investigate the container closure integrity of a closed system transfer device syringe adaptor lock in combination with disposable Luer-Lock syringes as the terminal closure device. The UK National Health Service (NHS) Pharmaceutical Quality Assurance Committee (PQAC) requires syringe integrity data for final storage devices of aseptic products such as chemotherapy drugs when prepared in advance and stored before use, as is standard practice for dose banded drugs. The assessment comprised both physical and microbial integrity testing of the combination closed system/Luer-Lock syringe containers at syringe sizes of 1 mL, 20 mL, and 50 mL. METHODS: Integrity testing was performed as described in the NHS Pharmaceutical Quality Assurance Committee yellow cover document, second edition 2013 'Protocols for the Integrity Testing of Syringes', with Chemfort (Simplivia, IL) syringe adaptor lock (SAL) devices as replacement for sterile blind hubs. Microbiological integrity was assessed according to method 1 part 1.4 using Brevundimonas diminuta at 32°C for up to 14 days of contact time. Two positive control devices per syringe size were tested using a blind hub cap as closure which was loosened before the test. Physical integrity was assessed using method 3 of the yellow cover document which is a dye intrusion method. Dye intrusion was assessed both visually and using a validated ultraviolet-visible spectrophotometer method. For each size/batch of test articles a positive control device (n=1) was assessed using a wire wrapped around the syringe plunger tip deliberately compromising integrity. Negative controls for each size (n=1) consisted of devices not immersed in methylene blue dye. RESULTS: Chemfort syringe adaptor lock/Luer-Lock syringe combinations were shown to be: (1) free of microbiological contamination after 14 days of contact time (n=60); and (2) free of dye intrusion at all syringe sizes tested (n=61 in total). The data demonstrate 100% closure integrity of the final container system when the Chemfort syringe adaptor lock replaces the syringe hub as the terminal closure device. All positive control devices demonstrated system suitability as container integrity was compromised in all positive control tests. All negative controls were negative for microbial and dye intrusion. CONCLUSIONS: Syringe adaptor lock components complied with the NHS Pharmaceutical Quality Assurance Committee yellow cover document syringe integrity requirements when used as the terminal closure of Luer-Lock disposable syringes from 1 mL up to 50 mL. Therefore, syringe adaptor lock (Chemfort) can be used as the terminal closure system for pre-filled syringes of chemotherapeutic drug products prepared in advance in UK NHS pharmacy technical services.

Assessment of the stability of citrate-buffered piperacillin/tazobactam for continuous infusion when stored in two commercially available elastomeric devices for outpatient parenteral antimicrobial chemotherapy: a study compliant with the NHS Yellow Cover Document requirements.

OBJECTIVES: To investigate the effect of pH control through the use of a citrate-buffered saline diluent pH 7 on the degradation rate of piperacillin/tazobactam solutions for infusion and to determine if an extended shelf-life of up to 13 days fridge 2°C-8°C plus 24 hours 'in-use' at 32°C in two elastomeric devices: FOLFusor LV10 (Baxter Healthcare, Thetford, UK) and Easypump II (B. Braun Medical Ltd, Sheffield, UK) can be achieved. METHODS: Testing was as per the latest National Health Service (NHS) Pharmaceutical Quality Assurance Committee Yellow Cover Document (YCD) requirements.A validated stability indicating high-performance liquid chromatography method was used for assessing the stability of the solutions of piperacillin/tazobactam at a combined concentration of 25 mg/mL and 90 mg/mL respectively. Solutions were tested in two batches in replicate (n=3) at five time points according to the requirements of the YCD. RESULTS: Piperacillin/tazobactam stability was significantly improved when 0.3% w/v citrate-buffered saline pH 7 was used as the diluent, compared with using 0.9% w/v saline as diluent. Greater than 95% of the zero-time concentration of both actives remained following storage at 2°C-8°C for up to 13 days plus 24 hours at 32°C in both devices. The data support extended storage of up to 13 days 2°C-8°C plus 24 hours at 32°C 'in-use' when using FOLFusor LV10 (Baxter) or Easypump II (B. Braun) pump devices. CONCLUSIONS: The enhanced stability complies with UK national standards as stated in the YCD for stability testing of aseptically produced small molecules and supports the storage of piperacillin/tazobactam for up to 13 days 2°C-8°C plus 24 hours at 32°C 'in-use' within two elastomeric pump devices. The extended shelf-life provides a significant advantage over the stability of piperacillin/tazobactam solutions for infusion when reconstituted and diluted in 0.9% w/v saline as diluent. The data open up the possibility of a continuous infusion of piperacillin/tazobactam delivered by elastomeric pump devices over 24 hours in an outpatient parenteral antimicrobial therapy setting.

Assessment of ceftolozane/tazobactam stability in elastomeric devices and suitability for continuous infusion via outpatient parenteral antimicrobial therapy.

OBJECTIVES: To investigate the stability of ceftolozane/tazobactam 5 mg/mL and 20 mg/mL solutions for infusion in two elastomeric devices: FOLFusor LV10 (Baxter Healthcare) and Easypump® II (B. Braun Medical Ltd) and determine if an extended shelf life of up to 8 days storage at 2-8°C plus 24 h 'in use' at 32°C was achievable. METHODS: Testing was as per the latest NHS Pharmaceutical Quality Assurance Committee Yellow Cover Document (YCD) requirements. A stability-indicating LC method was used for assessing the stability of solutions of ceftolozane/tazobactam at 5 mg/mL and 20 mg/mL (combined concentration of both actives) respectively, tested in two batches in triplicate (n = 3) at five timepoints according to the requirements of the YCD. RESULTS: Ceftolozane/tazobactam, diluted in 0.9% w/v sodium chloride at 5 mg/mL and 20 mg/mL, degraded during in-use storage at 32°C with <95% remaining after 18 h for some device/concentration combinations and all device/concentration combinations at 24 h, respectively. The data does support extended storage of up to 8 days at 2-8°C plus 12 h at 32°C 'in-use' when using either FOLFusor LV10 or Easypump® II devices and is compliant with YCD. CONCLUSIONS: Solutions of ceftolozane/tazobactam can be administered in outpatient parenteral antimicrobial therapy (OPAT) services following refrigerated storage for up to 8 days, when limited to a 12 h infusion at in-use temperature of 32°C. For UK OPAT services where twice daily dosing is feasible, our data provides another treatment option for challenging infections. In countries where a 10% loss of ceftolozane/tazobactam is acceptable, a 24 h infusion is supported by the data.

Investigation of meropenem stability after reconstitution: the influence of buffering and challenges to meet the NHS Yellow Cover Document compliance for continuous infusions in an outpatient setting.

Objectives: To determine the influence of different buffers, pH and meropenem concentrations on the degradation rates of meropenem in aqueous solution during storage at 32°C, with the aim of developing a formulation suitable for 24-hour infusion in an ambulatory elastomeric device, compliant with the latest National Health Service Pharmaceutical Quality Assurance Committee Yellow Cover Document (YCD) requirements. Methods: Meropenem was diluted to 6.25 mg/mL and 25 mg/mL in aqueous solutions adjusted to various pH with phosphate or citrate buffer and assessed for stability. Meropenem concentrations were determined using a validated stability-indicating high-performance liquid chromatography method at time 0 and following storage for up to 24 hours at 32°C as per the YCD requirements. Results: Degradation was observed to be slowest in citrate buffer around pH 7 and at a meropenem concentration of 6.25 mg/mL; however, losses exceeded 10% after storage for 24 hours at 32°C in all of the diluents tested in the study. Conclusions: Meropenem at concentrations between 6.25 mg/mL and 25 mg/mL as tested is not sufficiently stable to administer as a 24-hour infusion in ambulatory device reservoirs. If the YCD 95% minimum content limit is applied, the infusion period must be reduced to less than 6 hours for body-worn devices, especially at the higher concentration studied (25 mg/mL). This limits the possibility of using elastomeric devices to deliver continuous infusions of meropenem as part of a wider outpatient parenteral antimicrobial therapy service.

Assessment of the stability of citrate-buffered flucloxacillin for injection when stored in two commercially available ambulatory elastomeric devices: INfusor LV (Baxter) and Accufuser (Woo Young Medical): a study compliant with the NHS Yellow Cover Document (YCD) requirements.

Objectives: To investigate the effect of pH and buffers on the degradation rate of flucloxacillin and to determine if flucloxacillin can be stabilised using a buffered diluent for up to 14 days when stored at 2°C-8°C including a 24-hour infusion period at 32°C in two elastomeric devices (Accufuser and INfusor LV) filled to 240 mL. Testing as per the NHS Pharmaceutical Quality Assurance Committee Yellow Cover Document (YCD) requirements. Methods: A validated stability indicating high-performance liquid chromatography method was used for assessing the stability of flucloxacillin diluted in 0.3% w/v citrate-buffered saline pH 7.0 when stored at 2°C-8°C in two ambulatory devices (Accufuser and INfusor LV). Flucloxacillin at 10 and 50 mg/mL diluted in 0.3% w/v citrate-buffered saline pH 7.0 to a final volume of 240 mL and stored at 2°C-8°C, including 24 hours at 32°C, was tested from two batches in replicate (n=3) at five time points for up to 14 days according to the requirements of the YCD. Results: Greater than 95% of the zero-time concentration of flucloxacillin at 10 and 50 mg/mL remained when stored at 2°C-8°C after 14 days including 24 hours at 32°C in both Accufuser and INfusor LV devices. Conclusions: Flucloxacillin sodium stability was improved, and complied with UK national standards, by using a diluent of 0.3% w/v citrate-buffered saline pH 7 in both Accufuser and INfusor LV ambulatory devices when filled to 240 mL. The data support assigning a shelf-life of up to 14 days (13 days stored at 2°C-8°C and 24 hours at 32°C). Flucloxacillin may now be used appropriately as a continuous 24-hour infusion in outpatient parenteral antimicrobial therapy services, providing further opportunity to avoid or shorten patient hospital stays, as well as support ideal antimicrobial stewardship principles.

Performance testing protocol for closed-system transfer devices used during pharmacy compounding and administration of hazardous drugs.

OBJECTIVES: The United States National Institute for Occupational Safety and Health (NIOSH) is developing a protocol to assess the containment performance of closed system transfer devices (CSTDs) when used for drug preparation (task 1) and administration (task 2) and published a draft protocol in September 2016. Nine possible surrogates were proposed by NIOSH for use in the testing. The objectives of this study were to: (A) select the most appropriate surrogate; (B) validate the NIOSH protocol using this surrogate; and (C) determine the containment performance of four commercial CSTDs as compared with an open system of needle and syringe using the validated NIOSH protocol. METHODS: 2-Phenoxyethanol (2-POE) was selected as a surrogate based on its water solubility, Henry's volatility constant, detectability by mass spectrometry, and non-toxicity. Standard analytical validation methods including system suitability, limit of detection (LOD), and limit of quantitation (LOQ) as well as system cleaning validation were performed. The amount of 2-POE released when the CSTDs were manipulated according to two tasks defined by NIOSH was determined using mass spectrometry coupled to thermal desorption and gas chromatography. This approach allows sensitivity of detection below 1 part per billion (ppb). Equashield, Tevadaptor (OnGuard), PhaSeal, and ChemoClave were assessed according to manufacturers' instructions for use. RESULTS: 2-POE was tested and validated for suitability of use within the NIOSH protocol. A simple and efficient cleaning protocol achieved consistently low background values, with an average value, based on 85 measurements, of 0.12 ppb with a 95% confidence interval (CI) of ±0.16 ppb. This gives an LOD for the tests of 0.35 ppb and an LOQ of 0.88 ppb. The Equashield, Tevadaptor (OnGuard), and PhaSeal devices all showed average releases, based on 10 measurements from five tests, that were less than the LOQ (i.e. < 0.88 ppb), while the ChemoClave Vial Shield with Spinning Spiros showed average releases of 2.9±2.3 ppb and 7.5±17.9 ppb for NIOSH tasks 1 and 2 respectively at the 95% confidence level. The open system of needle and syringe showed releases, based on two measurements from a single test, of 4.2±2.2 ppb and 5.1±1.7 ppb for NIOSH tasks 1 and 2 respectively at the 95% confidence level. CONCLUSIONS: 2-POE proved to be an ideal surrogate for testing of CSTDs using the NIOSH protocol. We propose that a CSTD can be qualified using the NIOSH testing approach if the experimental LOQ is less than 1 ppb and the release values are below the LOQ. Equashield, Tevadaptor (OnGuard), and PhaSeal meet these acceptance criteria and can therefore all be qualified as CSTDs, but the ChemoClave system does not and so would not qualify as a CSTD.

Laser induced disruption of bacterial spores on a microchip.

We report on the development of a laser based spore disruption method. Bacillus globigii spores were mixed with a laser light absorbing matrix and co-crystallized into 200-microm-wide and 20-microm-deep nanovials formed in a polydimethylsiloxane (PDMS) target plate. Surface tension effects were exploited to effect up to 125-fold spore enrichment. When the target zones were illuminated at atmospheric pressure with pulsed UV-laser light at fluences below 20 mJ cm(-2) a change in spore morphology was observed within seconds. Post illumination PCR analysis suggests the release of endogenous DNA indicative of spore disruption. For laser fluences above 20 mJ cm(-2), desorption of spores and fragments was also observed even without a matrix being employed. Desorbed material was collected in a PDMS flowcell attached to the target plate during laser illumination. This opens up a route towards the direct extraction of released DNA in an integrated spore disruption-PCR amplification microchip device.

A dynamic structure for the acyl-enzyme species of the antibiotic aztreonam with the Citrobacter freundii beta-lactamase revealed by infrared spectroscopy and molecular dynamics simulations.

Infrared difference spectra show that at least 4 conformations coexist for the ester carbonyl group of the stable acyl-enzyme species formed between the antibiotic aztreonam and the class C beta-lactamase from Citrobacter freundii. A novel method for the assignment of the bands that arise from the ester carbonyl group has been employed. This has made use of the finding that the infrared absorption intensity of aliphatic esters is surprisingly constant, so a direct comparison with simple model esters has been possible. This has allowed a clear distinction to be made between ester and amide (protein) absorptions. The polarity of the conformer environment varies from hexane-like to strongly hydrogen-bonded. We assume that the conformer with the lowest frequency (1,690 cm(-)(1)) and hence the strongest hydrogen-bonding is the singular conformer observed in the X-ray crystallographic structure, since a good interaction via two hydrogen bonds with the oxyanion hole is seen. Molecular dynamics simulation by the method of locally enhanced sampling revealed that the motion of the ester carbonyl of the acyl-enzyme species in and out of the oxyanion hole is facile. The simulation revealed two pathways for this motion that would go through intermediates that first break one or the other of the two hydrogen bonds to the oxyanion hole, prior to departure of the carbonyl moiety out of the active site. It is likely that such motion for the acyl-enzyme species might also occur with more typical beta-lactam substrates for beta-lactamases, but their detection in the more rapid time scale may prove a challenge.