BD Oncology

Benefits of implementing a gravimetric system within oncology compounding

Volumetric compounding of IV oncology drugs has historically required the individual compounder, or second checker, to verify that each step of the compounding process is correct by a manual inspection method.

Gravimetric compounding however uses technology to perform this verification. Via an electronic balance and the known density of each ingredient, gravimetric systems confirm the accuracy electronically of volumes drawn up and doses prepared. This reduces the requirement for manual verification of volumetrically prepared doses.

But before we look at the benefits of gravimetric system within compounding, it is worth highlighting some of the issues pharmacists face with manual volumetric compounding.


The issues with manual compounding

  • There is a pressure on staff to identify errors visually, and this can be especially challenging in a busy pharmacy department and may result in errors going undetected.
  • A second staff member being required to perform in-process checks is labour intensive.
  • Compounding errors are often identified at the final verification stage by the pharmacist, rather than during the process. As a result, the incorrectly prepared dose usually has to be discarded and completely re-made. This is wasteful of potentially expensive drugs and having to remake the dose is time consuming for both the compounder and pharmacist.
  • Errors during compounding may be undetectable by manual inspection during final verification process by the pharmacist, and therefore potentially reach the patient.
  • The quantity of remaining part-used drug in vials can’t be accurately calculated due to vials often containing an overage initially. Therefore, if being returned to inventory, there will not be an accurate drug inventory level.

What is a gravimetric system in oncology compounding?

A gravimetric system involves weighing drugs and diluents at each step of the compounding process using an electronic balance. It is used to confirm the accuracy of the volume drawn up by comparing it to the known density of the constituent within the system’s database. This ensures that the volume falls within an acceptable margin of error.1

Automated* IV medication workflows using gravimetric technology, such as BD Cato™, provide step-by-step instructions to guide the user through the compounding process, and combined with barcode scanners, gravimetric scales and cameras, help ensure the correct preparation of a drug.

Gravimetric technique is key in detecting dose errors

Terkola 2017, was a study aimed at detecting medication errors with possible critical therapeutic impact in 10 centres in five European countries following the introduction of an intravenous workflow software gravimetric system.2The mean out-of-tolerance error rate across the 10 centres (n=759,060 preparations) was 10.44%. The proportion of antineoplastic preparations with deviations >10% of target dose ranged from 0.49% to 5.04% across sites, with a mean of 2.25%. The study concluded it was highly likely these errors would have gone undetected using traditional volumetric preparation methods.

Reducing compounding time and pharmacist final checking time

The BD Cato™ system identifies errors at the point they occur during the compounding process with alerts and hard-stops, enabling them to be corrected and rectified immediately, rather than at the end of the process. This can result in a reduced requirement to re-make doses.

Reece et al described the implementation and evaluation of a gravimetric i.v. workflow software system (BD Cato™) in an oncology ambulatory care pharmacy1. Due to a reduction in errors needing to be corrected post-production, the study reported that after the implementation of the gravimetric system the mean technician compounding time was reduced by 3.2 minutes, or 34%, and the mean pharmacist final checking time reduced by 1.17 minutes, or 37%.

It can be assumed that reducing the time taken for staff to perform the compounding checking processes can lead to an increased output of chemotherapy doses by the pharmacy, or these staff members can be re-allocated to perform other value-added tasks. Likewise, using technology to perform the in-process checks during compounding rather than having a second member of staff doing manual checks will also free-up staff time.

Better inventory management can significantly cut waste

With an automated checking and comprehensive inventory management as modules within the gravimetric process the pharmacist always has an accurate record of the remaining unused drugs. So leftover drugs in vials that often have to be disposed can be returned to inventory. Added to that, the most appropriately sized vial with shortest in-use stability date can be selected, reducing waste further.

Cutting costs by cutting waste

Two separate studies have highlighted tangible cost savings through implementing gravimetric systems.

The Reece et al. study discussed previously reported that prior to the implementation of the gravimetric system, the 49 errors detected at the final verification stage had to be discarded, amounting to over $56,000 in waste.1After the introduction of the gravimetric system, 12 of the 1126 errors detected required vials to be rejected due to incorrect reconstitution, resulting in $12,398 in waste. The remaining 1,114 errors detected with the gravimetric system were corrected before the final dose was completed and did not incur waste. This demonstrates that being able to identify errors at the point they occur results in overall waste reduction, and therefore reduced costs.

A European study investigated the economic impact of the preparation scenario for cytotoxic drugs using BD PhaSeal™. It showed that the CSDT savings due to minimization of vials wastage was up to €117,971 or up to € 38 per preparation.3

About BD Cato™

BD Cato™ provides clear, step-by-step instructions to guide the technician though the compounding process. Barcode scanners, gravimetric scales and cameras are all used to ensure the correct preparation of a drug, with alerts and hard stops if errors are detected. If BD Cato™ detects an error, it instructs the user how to correct it, and only once corrected can they progress. When compounding is completed, a unique label is printed. Where there is drug remaining in a vial, there is the possibility to print an additional label, detailing the quantity remaining and “in-use stability date, allowing it to be returned to stock and used for future preparations.

The pharmacist then uses BD Cato™ and a barcode scanner to final check and approve the preparation for use. All stages of the compounding process have been documented electronically and can be reviewed as and when required.

Tangible benefits of implementing a gravimetric system

The benefits from implementing BD Cato™, a gravimetric compounding system, can help to significantly improve your pharmacy compounding service in oncology. This is a result of:

  • Increased capacity and productivity of the pharmacy compounding service. This can help meet the growing demand for chemotherapy from increased patient numbers.
  • Increased patient satisfaction due to decreased waiting times for their chemotherapy, because of reduced preparation time.
  • Increased nurse satisfaction because of fewer dissatisfied patients, as a result of reduced waiting time.
  • Increased satisfaction and motivation of pharmacy staff due to standardization of compounding processes, and a reduction of the pressures that can occur with manual checking.
  • The freeing-up of time for pharmacy staff to perform other value-added tasks within the department due to reduced preparation time.
  • Cost savings through reduced drug wastage due to effective inventory management unused drugs.
  • Cost savings through detection and correction of errors at the point they occur, rather than detection at the final verification process and the dose having to be remade.
  • An increase in the ease of performing a systematic review of the metrics concerning compounding, due to electronic documentation of each step of the process.

Proven in action

In the East Tallinn Central Hospital, Estonia a report on the adoption of BD Cato™ found that it was able to “… significantly improve efficiency and quality but also communication between physicians and pharmacists”. What’s more it showed that BD Catot doubled the output of compounded doses per annum without an increase in staff headcount.

Read the full case study here

Where BD can play a part



Drug prescription

Clinician prescribes chemotherapy on BD Cato™ Prescribe

BD Cato™ Prescribe:

  • Aligns prescription with latest clinical results
  • Automatic warning of dosage modifications and dose limits

Prescription is sent electronically to the pharmacy.


Venous access

A port is a vascular access device implanted into the patient to provide repeated access to the vascular system. Safe chemotherapy treatment rely on safe vascular access.



Order verification

Pharmacist-verified order is sent electronically to BD Cato™ Pharmacy. BD Cato™ Pharmacy automaticallyprioritizes orders according to the patient scheduler. Pharmacist can select the shortest dated vial to ensure that drug wastage is limited.


Drug preparation

BD PhaSeal™ close system transfer device is used for preparation and theBD MicroBore secondary set is used to spike the bag


Gravimetric analysis

Gravimetric scales checks the right dose is drawn via drug density calculation. Scan the barcode on the vial to identify the right drug. Camera capture each step.


Drug verification

Unique barcode medication label is printed once all steps are a corrected followed. Pharmacist verifies preparation.



Patient preparation

Nurse prepares patient for administration of hazardous drugs utilizing closed system transfer deviceBD MicroBore set.


Patient assessment

BD Cato™ ReadyMed check if it is the right part in and right drug and will automatically document this is the system.


Pump programming

Use BD BodyGuard™ Duo with its two independent infusion channels in one intuituve, user-friendly interface, which can help simplify the infusion of even the most complex therapies.

Contact us