Repackaging (prepacking, assembly)

Repackaging (prepacking, assembly)

Scope

Repackaging is a process in which liquid or solid-dose formulations are packed from bulk into smaller, ready-to-use containers (prepacks). The presentation of prepacks, in terms of the number of tablets or capsules or volume of liquid, the label details and the container type, are designed to meet a specific clinical need. Until the mid-1990s, the most common prepackaging activity undertaken by hospital pharmacy departments was the production of ward packs. Bulk packs of tablets and capsules (typically 500–5000 dose units) and large containers of liquid medicines (up to 2 litres) were economic to purchase, particularly from manufacturers of generics. However, it was neither economical nor safe to place such large containers on hospital wards as stock medicines. Therefore ward packs were produced by repacking bulk medicines into pack sizes of typically 25–50 solid-dose units per pack or 50–200 ml of liquid medicines per bottle. Repackaging also provided an opportunity to improve the clarity of labelling. The proprietary or trade name of the medicine was often prominent on bulk packs but the prepacks could be labelled with the approved name of the medicine to reduce the risk of drug administration errors on the ward.

In recent years the increased availability of commercially produced ward packs which carry full UK marketing authorisation has reduced the need for in-house production of ward packs. Also the introduction of patient packs containing strips of blister-packed tablets and capsules has provided another presentation that can be adapted for ward use by simply overlabelling the outer carton. Although there will be a continued demand for a limited range of ward packs which are not commercially available, the emphasis of hospital repackaging activities is now directed towards more patient-specific packs which are not commercially viable. These include prepacks for hospital dis-charge medication and packs designed to meet the requirements of specific treatment protocols or patient group directives in primary, secondary and tertiary care settings. The objective in both cases is to produce a presentation that exactly meets specific clinical and patient requirements while minimising repetitive, labour-intensive dispensing work. Providing the exact number of doses needed by the patient also reduces drug wastage. The MHRA provides guidance on the requirement for a special assembly licence for repackaging, depending on the batch size and the frequency with which batches are pro-duced. Increasingly, hospital repackaging has become more centralised in specialist units with automated packing lines. Although repackaging whole strips of blister-packed medicines into different containers is accept-able, the removal of tablets or capsules from blisters for repackaging is not advisable since stability cannot be guaranteed. However, any repackaging needs to be considered in terms of whether value is truly added and standard-isation to a limited range is advisable.

Facilities and equipment

In its simplest form, repackaging is a manual operation in which counting of tablets, capsules and measuring of liquids are achieved with tablet triangles, capsule trays and glass measures. Containers are also capped and labelled by hand, although all labels are either preprinted or produced on a computer labelling system. Repackaging activities require a clean, uncluttered, designated area. Walls, floors and work surfaces should be of a smooth, impervious finish and should be readily accessible for easy cleaning. Although most tablets are now coated, dust containing active drug can be generated during repackaging and a localised dust extraction system should be fitted.

The degree of automation of repackaging processes ranges from semi-automatic tablet and capsule-counting machines to fully automated pack-ing lines. In the case of the latter, empty containers are sorted, oriented and then transported to the filling zone by a conveyor track. Tablets or capsules are fed from a hopper over a chip-sieve to counting heads, which fill the correct number of dose units into each container. The containers progress to an automated capping system before preprinted labels are applied auto-matically.

Alternatively, automatic packing lines can pack solid doses into preformed blisters or foil pouches to produce blister and foil packs.

Many packing lines are fitted with localised dust extraction in critical areas and also electronic check-weight systems to assure correct counting and filling processes. An example of a fully automatic packing line is shown in Figure 6.1. This type of equipment must be easily dismantled and re-assembled to permit cleaning and inspection between batch runs.

Process

Whilst repackaging processes are simple, errors can occur. To avoid transposition of medicines or labels it is essential that only one batch is repackaged at a time in a designated area and that the work area is cleared of all labels, containers and medicines from the previous batch. With solid-dose forms, it is good practice to organise the repackaging schedule so that medicines differ from the previous batch repackaged in colour, shape, size or appearance. This makes it easier to detect the odd rogue tablet or capsule transposed to another batch of a different product in error.

It is also important that cleaning procedures for equipment are carefully validated, particularly if sensitising antibiotics such as penicillins are repack-aged, to ensure that medicines are not contaminated with dust from previous batches.

When repackaging liquids (particularly suspensions) it is essential to shake the bulk container thoroughly before distributing the liquid to the prepack containers. This ensures that the concentration of drug in all prepacked containers is homogeneous. In practice, these processes are mainly controlled through standard operating procedures, batch documen-tation, staff training and competency assessment. In the case of liquid suspensions, routine sampling and QC testing during a batch run are introduced to ensure the homogeneous content is maintained. The recon-ciliation of the number of dose units used, the number of packs produced and the number of labels issued and used all require particular consider-ation. These controls should be part of a comprehensive QA system, which will also include QC, self-inspection, error reporting and feedback from ‘customers’.