Unit Dosing

Unit Dosing

How can we reduce administration errors through the effective introduction of unit dose packaging?

A unit dose package can be described as a package that contains the particular dose of a drug for use by a specific patient in accordance to the patient’s specific prescription.  The defining feature is that each patient specific dose is uniquely identified.


This can be seen most clearly with blister packs.  Whilst each blister provides an individual package for each tablet, the labelling is often printed across the complete blister strip but not replicated in a way to provide uniquely identified blister pockets.  A most effective design of unit dose blister pack is where not only is each single dose uniquely and fully labelled but also each dose is easy to detach from the strip through a perforation.


There are two main reasons why unit dosing is important – to ensure correct administration use and to assure the providence of the individual doses at point of use.


If we firstly consider the issue of correct administration, 38% of medication errors are due to administration errors (1).  One of the reasons for this is the difficulty in effectively ensuring that the correct product has been selected where there is a blister pack without unit dosage labelling.  In hospital wards and dispensaries, the blister pack will be cut up for administration to the patient.  If unit dosage labelling is not present it can be extremely difficult to identify what the product is from a single cut off blister.  Moreover, as more blisters are cut from the strip, it becomes increasing difficult to identify what the product is contained in the remaining strip.


Further control can be provided through the application of a product identifying barcode on each unit dose package.  This has been demonstrated to reduce error by 41.4% (2).  In light of this the European Association of Hospital Pharmacists calls for “each single dose of medicine used within hospitals and supplied to the hospital by manufacturers or wholesalers to include an individual barcode in GS1 datamatrix format.”


Therefore unit dosage packaging can have a significant impact on patient safety and product administration effectiveness.  Indeed the Council of Europe Report (2007) on “Creation of a better medication safety culture in Europe: Building up safe medication practices” from the Expert Group on Safe Medication Practices, stated that “Medicines should be provided in unit dose presentations, ready for use and administration, in order to help minimising the occurrence of errors.”  Furthermore, driven by a desire to reduce medication administration errors, the FDA has mandated that medicines supplied to hospitals are bar-coded to the smallest unit of administration.


The second issue highlighted above, concerns the assurance of the providence of an individual dose at the point of use.  Whilst current serialisation and track and trace legislation has been focussed at the saleable unit (which is typically pack level), there has always been an underlying conversation about product identification at the unit dose level.  The trials and tribulations involved with implementation of serialisation legislation across the industry make achievement of serialised product at a pack level a significant enough challenge, but when this has been achieved, will the legislators’ attention be drawn to serialised product at the unit dose level?


This presents a convergence of desired outcomes, as hospitals drive for unit dosage packaging and labelling to prevent administration errors, while legislators look for unit dose serialised product to assure product authenticity.

So why aren’t all blister packs provided with a unit dose design?  This is where things get difficult.  In most cases the artwork is not designed to fit the blister.  More often it is a repeating pattern of product information across the blister.


In order to fit all of the desired information on each blister in a legible manner, significant redesign of the secondary packaging and artwork may be required.  This will likely impact tooling and equipment design, and where small tablets and blisters are involved may not be feasible without substantial re-engineering.  The volume of product impacted would drive significant change in both companies and regulators with associated cost and the risk of introducing artwork error.


Pharmaceutical companies are also trying to manage their portfolio complexity and rationalisation of product formats and offerings is an underlying requirement to make this happen.  Therefore special features such as perforations may not be feasible.


Whilst there have been some attempts at providing guidance, there are no clear, defined regional standards to follow on artwork layout and format.  This risks individual companies developing their own approaches creating an additional level of complexity.


We would all agree that improving patient safety is a priority that must be maintained but, taking into account all of the above sensitivities and at a time when there is real pressure on healthcare costs, achieving this magnitude of change may be infeasible.  Therefore the question remains – how can we reduce administration errors through the effective introduction of unit dose packaging?

(1)  Leape LL, Bates DW, et al. JAMA. 1995 Jul 5;274(1):35-43

(2)  Poon EG et al. Effect of Bar-Code Technology on the Safety of Medication Administration. N Eng J Med 2010;362:1698-707

Comment ( 1 )

  • Eswara Krishnan

    it is nice to note the concerns which are important and necessity. just a thought come to my mind. why not insist on printing on the tablets with registered marking which can identify the product even if we remove from the blister. as cut blister if this need to be checked, this can be done by printing on both side of tablet.

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