Units of Measure

What's new in this release?

Some additional information about the uL and Plaque forming units. Refer to the FSN format section below.

Units of Measure

General considerations

• Representation of the units will first be taken from UCUM Standard (The Unified Code for Units of Measure)
• Units are plural when it is grammatically appropriate
• US spelling is preferred over UK spelling. 

For example: Milliliter vs millilitre: milliliter is preferred

• When a number precedes the unit it will take a ‘s’ if greater than 1

For example: Engerix B 20 micrograms per milliliter suspension for injection GlaxoSmithKline Inc. (product)

• If we decided to add a synonym with the unit symbols, the UCUM format (mL) would be preferred  

The FSN format 

The unit is part of the strength information which is found only in FSN, where the units of measure should not be abbreviated, and always expanded.   

• Lf (limit of flocculation)
  • The term ‘unit’ is added and will be singular or plural if more than one (1) unit

For example: 2 LF / 0.5 ML vs 2 limit of flocculation units per 0.5 milliliter 

• ELISA units                      
  • Curly braces will not be used

For example: 1440 ELISA Units/mL will become 1440 ELISA units per 0.5 milliliter  

• B
  • In UCUM B = bel but this description does not seem to be appropriate for drug strength
  • It could be translated in ‘billion cells’, but we will not enter this strength in the FSN, because too difficult to express clearly.

For example: Instead of "Vivotif 10 billion cells enteric coated capsule Crucell Switzerland LTD (product)" we will have: "Vivotif enteric coated capsule Crucell Switzerland LTD (product)" 

• ug or uL
  • This is represented by microgram or microliter

For example: FSME-IMMUN 2.4 micrograms per 0.5 milliliter suspension for injection Baxter AG (product) 

For example: ACAM2000 250000 to 1250000 plaque forming units per 2.5 microliter powder and diluent for solution for percutaneous scarification Emergent Product Development Gaithersburg Inc. (real clinical drug)

•  Plaque forming units (PFU)
  • The abbreviation is expanded in the FSN
  • Curly braces are not used
  • Exponential number cannot be represented in SNOMED CT 
  • The term ‘unit’ is added and will be singular or plural if more than one (1) unit

For example: Varivax III 1350 plaque forming units powder and diluent for solution for injection Merck Canada Inc. (product)

• 1.0 mL
  • There are inconsistencies using 1.0 mL or /mL
  • UCUM guidelines are followed to be consistent with lab existing content.
  • 1.0 will not be added to the FSN 

For example: Recombivax HB 10 micrograms per milliliter suspension for injection Merck Canada Inc. (product) 

• iU
  • This is represented by ‘International unit’

For example: Imovax Rabies 2.5 international units per milliliter powder for solution for injection Sanofi Pasteur SA (product)

• CCID50
  • In UCUM, defined as : cell culture infectious dose 50% unit
  • The above definition will not be part of the FSN, it will rather be represented as follow:

Strength:  1000000 CCID50 /ML for Rotarix will become: 

Rotarix 1000000 units per milliliter oral suspension GlaxoSmithKline Inc. (product)