Physicochemical stability of voriconazole in elastomeric devices

Widening the net: a literature review of antimicrobial agents with potential suitability for outpatient parenteral antimicrobial therapy services-the importance of storage and stability

OBJECTIVES

Outpatient parenteral antimicrobial therapy (OPAT) services using continuous infusions (CIs) of antimicrobial agents in elastomeric devices require evidence of acceptable stability of the agent over the infusion period. A period of refrigerated storage of filled devices, followed by the CI period, is useful for OPAT services but can present a significant challenge to the stability of drugs. The aims of this study were to review fresh-filled stability data on antimicrobials which would be useful for OPAT services and to identify suitable candidates for further assessment.

METHODS

Searches identified papers relating to stability assessments of antimicrobials for immediate use tested above 31°C using a stability-indicating method.

RESULTS

We identified 18 stability studies published in 12 papers between 2015 and 2020, assessing the stability of 10 agents. Aminopenicillins like ampicillin and amoxicillin appear too unstable for CI, while benzylpenicillin may benefit from buffering to improve its stability. Cephalosporins vary in their stability and CI periods of 24 hours may not be achievable. Of the carbapenems, there are insufficient data for doripenem but meropenem has been extensively studied and is unsuitable for CI longer than 6 hours. Voriconazole may be suitable for CI but needs further investigation.

CONCLUSIONS

Some drugs identified in our review are unlikely to be suitable for continuous infusion in OPAT services due to instability. Using a 'fresh-fill' approach, without refrigerated storage, may make some drugs useful while other agents should be considered for further assessment to Yellow Cover Document standards. The impact of buffering for penicillins should be assessed further.

Stability of Antimicrobials in Elastomeric Pumps: A Systematic Review

Outpatient parenteral antimicrobial therapy (OPAThttp) programs have become an important healthcare tool around the world. Portable elastomeric infusion pumps are functional devices for ambulatory delivery of antimicrobial drugs, and their stability is an essential point to guarantee an appropriate infusion administration. We conducted a systematic review to provide a synthesis and a critical evaluation of the current evidence regarding antimicrobial stability in elastomeric pumps. Data sources were PubMed, EMBASE, and Web of Sciences. The review protocol was registered on the Center for Open Science, and it was carried out following the PRISMA guidelines. Studies were eligible if the aim was the evaluation of the physicochemical stability of an antimicrobial agent stored in an elastomeric device. Of the 613 papers identified, 33 met the inclusion criteria. The most studied group of antimicrobials was penicillins, followed by cephalosporins and carbapenems. In general, the stability results of the antimicrobials that have been studied in more than one article agree with each other, with the exception of ampicillin, flucloxacillin, and ceftazidime. The antibiotics that displayed a longer stability were glycopeptides and clindamycin. Regarding the stability of antifungals and antivirals, only caspofungin, voriconazole, and ganciclovir have been investigated. The information provided in this article should be considered in patient treatments within the OPAT setting. Further stability studies are needed to confirm the appropriate use of the antimicrobials included in this program to ensure optimal patient outcomes.

Impact of air temperature and drug concentration on liquid emission from elastomeric pumps

Background

Elastomeric pumps (EPs) are devices that allow quantitative and continuous drug administration without the need for electronic control, and they are used by being filled with anticancer agents. Although the package inserts of several manufacturers that provide EPs describe the relationship between the flow rate per unit time and temperature, the solution is only saline solution or 5% glucose solution, and data on anticancer drugs have not been published. In this study, we focused on 5-fluorouracil (5-FU), a drug frequently used in cancer chemotherapy, and examined the effect of changes in standard of EPs and temperature on drug emission.

Methods

We evaluated the EP data of patients treated with Baxter Infusor® LV5 and SV2.5 in terms of emission rate, relationship between 5-FU prescription amount and emission rate, and relationship between emission rate and monthly air temperature in LV5 and SV2.5. The number of EPs sampled in the study was N = 5708 (n = 2988 for LV5 and n = 2720 for SV2.5).

Results

In LV5, the emission rate varied from 88 to 97% (median 94.0%), whereas in SV2.5, the emission rate was observed as 97 to 98% (median 97.4%). The 5-FU prescription amount and the emission rate were not correlated in LV5 and SV2.5, respectively (LV5; y = − 0.0015x + 97.305, R² = 0.0226, SV2.5; y = − 0.001x + 100.25, R² = 0.0466). LV5 showed a higher emission rate in the months with higher air temperature and a lower emission rate in the month with lower air temperature. In addition, LV5 showed a significant reduction in emission rate compared with SV2.5 in all months (P < 0.001).

Conclusions

In this study, we clarified that air temperature is an important factor that affects the drug emission of EPs. Therefore, it is necessary to examine the conditions for total fluid volume suitable for the air temperature in each region and to provide sufficient information to patients.

Physicochemical stability of extemporaneously prepared clonidine solutions for use in neonatal abstinence syndrome

WHAT IS KNOWN AND OBJECTIVE

Extemporaneously prepared clonidine admixture is increasingly used for the management of neonatal abstinence syndrome. However, its stability beyond 15 minutes at room temperature is currently unknown. Therefore, healthcare professionals must prepare clonidine admixtures multiple times a day while the treatment is indicated, resulting in subsequent limitations and problems. The aim of this study was to investigate the physicochemical stability of clonidine in commonly used pharmaceutical diluents at clinically relevant concentrations and temperatures.

METHODS

Glass bottles (n = 18) and plastic syringes (n = 18) containing 0.5 and 5 µg/mL of clonidine in either 5% glucose, 10% glucose or 0.9% normal saline were prepared and stored at 4°C for 7 days and at 35°C for 24 hours, respectively. Aliquots were withdrawn at predefined time points and analysed for the concentration of clonidine, changes in pH and colour, and particle content.

RESULTS AND DISCUSSION

No evidence of particle formation, or colour or pH change was observed throughout the study period. Clonidine retained more than 98% of its initial concentration when stored in the tested diluents at 4°C for 7 days and at 35°C for 24 hours.

WHAT IS NEW AND CONCLUSION

Our findings will allow healthcare professionals to prepare weekly dose of clonidine in glass bottles for storage in a refrigerator. The daily required dose of clonidine can be drawn aseptically from the glass bottle each day and stored in a plastic syringe at room temperature. Clonidine present in a plastic syringe can be administered via the nasogastric route 4-6 times a day. This practice would not only save nursing time and avoid delays in the timely administration of clonidine, but also reduce the risk of potential medication errors as well as preparation-associated costs.