Deblistering of tablets and capsules in order to repackage them as fully labelled unit doses could reduce the risk of administration errors but may compromise the integrity of the final products
Laurence A Goldberg
Unit dose drug distribution (UDD) systems were introduced into hospitals in the USA in the early 1960s in order to achieve a number of objectives. These included prevention of theft (often described as “diversion” in the US literature), provision of clear audit trails, identification of accurate costs for third party charging purposes and reduction in drug administration errors.
The term “unit dose” is used to describe a form of packaging in which each individual dose is separately packaged and labelled with the product name, strength and expiry date. A barcode identifier has been added in recent times. For solid oral dose forms unit doses can be presented as individual, blister-packed doses, foil-wrapped doses or doses in individual sachets. A different form of unit dose packaging is where a number of doses to be taken at the same time are packed in the same sachet. This form of medicines’ packaging has been used, for example, for patients in residential care homes, in sheltered accommodation or for patients living alone who may otherwise have difficulties with adherence.
Unit doses of liquid formulations can be provided in small tubs (like milk) or in plastic tubes. Unit doses of eye drops and eye ointment have long been available for use in emergency departments.
American authors have put forward the view that UDD systems should be adopted in all secondary health care systems worldwide. These recommendations have not taken into account local circumstances. It should be remembered that many large American hospital pharmacies are open for 24 hours a day, seven days a week and employ very large numbers of staff – two features that are essential for operating an efficient American-style UDD system. Although the way in which hospital pharmacies operate in Europe is usually very different from their counterparts in the USA, some have decided to follow the unit dose route. This has given rise to a dilemma. In the USA, hospitals can purchase medicines packaged in unit doses by the manufacturer. Thus, for example, a pack of 1000 tablets would consist of 1000 individually packed, labelled and bar-coded tablets. Furthermore, these tablets will have been subject to stringent stability testing by the manufacturer.
In Europe, some hospitals are operating UDD systems even though the pharmaceutical industry is not supplying unit doses. Most solid oral doses are offered in standard blister packs. The outer pack is labelled with the name and strength of the medicine but often the individual blisters are not. In order to convert this type of packaging into a UDD system, pharmacists have adopted one of the two options available to them- namely deblistering and repackaging of single tablets or capsules into separate sachets or separation of blisters by cutting between them and over-wrapping the individual blisters in separate sachets.
Deblistering (i.e. removing the doses from the original manufacturer’s blister packs) is associated with a number of problems. First, it is a time-consuming and labour-intensive process (if done by hand). Automatic and manually-operated deblistering machines have recently been introduced for this purpose. Second, once deblistered the loose doses are put into designated, pre-calibrated cassettes, which, in turn, are placed in an automated packing machine. These cassettes are moved into position when doses need to be packaged. The cassette releases a dose, which drops down a chute into the packing line. As it is difficult to clean the chute after each dose the possibility of cross-contamination arises. Third, the stability of the final product cannot be guaranteed because the manufacturer’s original pack has been compromised. Different approaches have been used to derive suitable expiry dates for the repackaged products. Some pharmacists have chosen to assign the manufacturer’s original expiry date and others have arbitrarily assigned an expiry date. The main problem here is that the stability of the repackaged products has usually not been validated.
Cutting and separation of individual blisters and over-wrapping them in individual sachets is another option. The main advantage of this method is that the integrity and stability of the original pack is not compromised. Again, machines are now available to separate the blisters by cutting between them. However, the disadvantages are that it is time-consuming to carry out and ergonomically it is difficult to open the blisters once they have been separated as there is little room for leverage.
- Can the objectives of UDD be achieved in any other ways? The process was developed in an era before barcoding, electronic prescribing, electronic medication administration recording and electronic audit trails had been introduced into health care. At the time UDD was the only way to reduce diversion, reduce medication errors and track costs for third party payment. Now all these objectives can be achieved using original manufacturers’ packs and sophisticated closed loop systems.
- Unit dose packaging comes at a cost. With the present economic constraints in European healthcare systems, can these additional costs be justified?
- Unit doses take up considerably more storage space than traditional packaging both in the pharmacy and in clinical areas.
- UDD may necessitate the provision of different types of ward storage units and medication trolleys.
- Unit doses with long shelf lives purchased from manufacturers can be positively identified and therefore readily recycled, leading to less wastage.
Hospitals in Europe are attempting to adopt the American model of UDD without having the staffing resources, without offering a 24-hour service and without having the medicines appropriately packaged by the industry. The process appears to be a compromise that brings into question basic pharmaceutical principles.
Perhaps hospitals in Europe should be joining together, agreeing on a specification for unit dose packaging and requesting the pharmaceutical industry to supply the doses in a form that will be fit for purpose.