A sequential temperature cycling study for the investigation of carboplatin infusion stability to facilitate `dose-banding'

Determining acceptance and perceptions of chemotherapy dose banding in an ambulatory cancer centre

INTRODUCTION

Despite the advantages of dose banding (DB) and numerous plans to adopt this practice, uptake of DB is still poor. As opinions of healthcare professionals were deemed essential in DB's acceptance, this study surveyed key stakeholders to determine the acceptance, facilitators, and barriers of DB in chemotherapy to improve its implementation.

METHODS

A cross-sectional study at the National Cancer Centre Singapore, involving physicians, nurses, and pharmacy staff, was conducted in February 2022. The Theory of Planned Behaviour was adapted to design a survey questionnaire to obtain the acceptance, facilitators, and barriers of DB. Additional questions on maximum acceptable dose variance and essential criteria for selecting drugs for DB were included.

RESULTS

A total of 93 participants responded, with a mean 9.75  ±  7.37 years of clinical experience. Less than half have heard of DB while few had prior experience. Drug cost was the top selection criteria for DB, followed by toxicity, therapeutic index, frequency of use and drug wastage. Acceptance rate of DB was 41.9%, with majority agreeing to use DB in various drugs but to determine patient suitability before usage. Being greatly affected by subjective norms, having a positive outlook for DB's impacts, and no effect on toxicity significantly influenced acceptance.

CONCLUSION

Prior to implementing DB at the institutional level, educational training addressing concerns over toxicity, and providing technological support can help improve acceptance. Future studies can involve patients' perspectives and more institutions for greater diversity in opinions.

Dose-banding of carboplatin: rationale and proposed banding scheme

Background. In dose-banding (DB) prescribed doses of cancer chemotherapy are fitted to doseranges or ‘bands’ and standard doses for each band are provided using a selection of pre-filled infusions or syringes, either singly or in combination. DB is used for several drugs where dose is based on body surface area. No DB-scheme has been reported for carboplatin, which, in clinical practice, is routinely dosed according to renal function.

Study objective. To assess the rationale for DB of carboplatin with regards to factors that influence dosing accuracy, develop a DB scheme, and discuss its potential use and limitations.

Methods. Prospective evaluations of carboplatin area under the plasma concentration – time curve (AUC) following application of the Calvert-formula were identified by a literature search. A relevant carboplatin dose range for construction of a DB-scheme with Calvert-formula based doses was obtained from published glomerular filtration rate distributions for patients receiving carboplatin.

Results. A DB-scheme was developed for individually calculated carboplatin doses of 358–1232 mg, with 35 mg increments between each standard dose and a maximum deviation of 4.7% from prescribed dose. The proposed DB-scheme covers the GFR-ranges 47–221 mL/min and 26–151 mL/min for patients receiving doses based on the target AUCs of 5 and 7 mg/mL/min, respectively.

Conclusion. There is a strong scientific rationale to support DB of carboplatin. The proposed banding scheme could introduce benefits to patients and healthcare staff but, as with other DB schemes, should be validated with prospective clinical and pharmacokinetic studies to confirm safety and efficacy.

Stability of tacrolimus solutions in polyolefin containers

PURPOSE

Results of a study to determine the stability of tacrolimus solutions stored in polyolefin containers under various temperature conditions are reported.

METHODS

Triplicate solutions of tacrolimus (0.001, 0.01, and 0.1 mg/mL) in 0.9% sodium chloride injection or 5% dextrose injection were prepared in polyolefin containers. Some samples were stored at room temperature (20-25 °C); others were refrigerated (2-8 °C) for 20 hours and then stored at room temperature for up to 28 hours. The solutions were analyzed by stability-indicating high-performance liquid chromatography (HPLC) assay at specified time points over 48 hours. Solution pH was measured and containers were visually inspected at each time point. Stability was defined as retention of at least 90% of the initial tacrolimus concentration.

RESULTS

All tested solutions retained over 90% of the initial tacrolimus concentration at all time points, with the exception of the 0.001-mg/mL solution prepared in 0.9% sodium chloride injection, which was deemed unstable beyond 24 hours. At all evaluated concentrations, mean solution pH values did not change significantly over 48 hours; no particle formation was detected.

CONCLUSION

During storage in polyolefin bags at room temperature, a 0.001-mg/mL solution of tacrolimus was stable for 24 hours when prepared in 0.9% sodium chloride injection and for at least 48 hours when prepared in 5% dextrose injection. Solutions of 0.01 and 0.1 mg/mL prepared in either diluent were stable for at least 48 hours, and the 0.01-mg/mL tacrolimus solution was also found to be stable throughout a sequential temperature protocol.

A UV-Raman spectrometry method for quality control of anticancer preparations: Results after 18 months of implementation in hospital pharmacy

In France, chemotherapy preparation units of hospital pharmacy compound cytotoxic infusion bags adapted to each patient. The narrow therapeutic index of these preparations led us to implement qualitative and quantitative control for patients' safety. To this aim, we calibrated an equipment combining UV-vis spectrometry and Raman spectroscopy (QC Prep+) and monitored 14 different molecule-solvent combinations over a 18 months period. This rapid and specific method allowed the qualitative and quantitative analysis of 1 mL sample tests in less than 2 min. On 5742 anticancer preparations, we obtained accepted results with more than 99.4% solvent identification, 99.6% drug identification and only 1.52% of preparations not matching quantitative specifications (±15% of theoretical concentration). This quantitative control enabled us to pinpoint some critical points of production for two of the most common preparations. We thus updated the procedures of reconstitution and preparation, increasing the quality of final product. UV-Raman spectrometry is thus an effective tool to control chemotherapy infusions and to improve good practices of preparation.

Stability study of carboplatin infusion solutions in 0.9% sodium chloride in polyvinyl chloride bags

Background and purpose

Carboplatin is a platinum-containing compound with efficacy against various malignancies. The physico-chemical stability of carboplatin in dextrose 5% water (D5W) has been thoroughly studied; however, there is a paucity of stability data in clinically relevant 0.9% sodium chloride infusion solutions. The manufacturer’s limited stability data in sodium chloride solutions hampers the flexibility of carboplatin usage in oncology patients. Hence, the purpose of this study is to determine the physical and chemical stability of carboplatin–sodium chloride intravenous solutions under different storage conditions.

Methods

The physico-chemical stability of 0.5 mg/mL, 2.0 mg/mL, and 4.0 mg/mL carboplatin–sodium chloride solutions prepared in polyvinyl chloride bags was determined following storage at room temperature under ambient fluorescent light and under refrigeration in the dark. Concentrations of carboplatin were measured at predetermined time points up to seven days using a stability-indicating high-performance liquid chromatography method.

Results

All tested solutions were found physically stable for at least seven days. The greatest chemical stability was observed under refrigerated storage conditions. At 4℃, all tested solutions were found chemically stable for at least seven days, with nominal losses of ≤6%. Following storage at room temperature exposed to normal fluorescent light, the chemical stability of 0.5 mg/mL, 2.0 mg/mL, and 4.0 mg/mL solutions was three days, five days, and seven days, respectively.

Conclusion

The extended physico-chemical stability of carboplatin prepared in sodium chloride reported herein permits advance preparation of these admixtures, facilitating pharmacy utility and operations. Since no antibacterial preservative is contained within these carboplatin solutions, we recommend storage, when prepared under specified aseptic conditions, no greater than 24 h at room temperature or three days under refrigeration.

A national survey investigating UK prescribers' opinions on chemotherapy dosing and 'dose-banding'

AIMS

The primary purpose of dose-banding for cancer chemotherapy is to reduce patient waiting times, but dose-banding also has additional benefits, such as reduced drug wastage, reduced stress for staff, and prospective quality control of infusions. However, the uptake of dose-banding seems fairly low. Possible reasons for this are a reluctance to use dose-banding for clinical reasons or a lack of awareness. Despite the seemingly minor change from established practice of dose preparation, dose-banding has the potential to alter patient chemotherapy exposure. The aim of this study was to investigate prescribers' awareness of dose-banding and their opinions on the scope and limitations of dose-banding in the context of UK chemotherapy services.

MATERIALS AND METHODS

This survey was performed throughout the UK by use of a postal questionnaire, which was validated before national distribution to 1104 oncologists and haematologists. The questionnaire contained both quantitative and qualitative elements. A database was created for data entry and analysis.

RESULTS

The response from prescribers was encouraging for a postal questionnaire, with a 35% response rate (387 responses). Many were aware of the concept of dose-banding (>80%) and were also supportive of the system. The weakness around body surface area-based dosing was a commonly discussed topic. However, opinions on which is the maximum acceptable deviation from the prescribed dose with dose-banding were controversial, and there was a concern about the lack of evidence to support the use of dose-banding. The views on whether carboplatin and targeted therapies should be dose-banded were also divided.

CONCLUSIONS

There was general support for dose-banding, but concerns about the lack of an evidence base could be a barrier to the wider introduction of the system. Consequently, more clinical studies are required to justify the safety and efficacy of dose-banding, and also to evaluate whether dose-banding is acceptable within clinical trials.