This page is written from Spain. The clinical criteria for repackaging are the same anywhere — they come from the dose form and the stability of the product — but the legal and regulatory sections are specific to Spain, and they are labelled as such. Where the UK position differs, it is stated. Follow your own regulator wherever you practise.
What a monitored dosage system is
A monitored dosage system (MDS) — also called a dosette box, a blister pack or a multi-compartment compliance aid — is a sealed tray into which a pharmacist repackages a patient's solid oral medicines, laid out by day and by time of day. It is a professional service that happens after dispensing: the therapy is reviewed, what can safely be repackaged is repackaged, the tray is labelled, and the patient is followed up.
It is not the same as a pill organiser the patient fills themselves. Those are not sealed, carry no traceability and involve no pharmacist check — which is precisely what an MDS adds, and what makes it a service rather than a box.
Manual
The pharmacist places the solid forms into the wells of the tray and seals it with foil or film.
Semi-automated
A loading tray plus software that checks batch numbers, expiry dates and traceability, and flags interactions.
Automated
Robots that fill trays or pouches in bulk, with a Datamatrix code for traceability.
1 Is this patient a candidate? — Suitability score
Answer a few questions about the patient and we will tell you how strong the case is.
The strongest candidates are patients who struggle to follow their treatment: several medicines a day, several doses, frequent missed doses, cognitive impairment, dexterity or eyesight problems, or nobody at home to help. Remember the caveat above: score high, then ask whether a simpler regimen would do the job better.
2 Can it be blistered? — Medicine checker
Add the patient's medicines and we will tell you which are suitable, which need care and which must stay out. Anything we do not hold is passed to the assistant.
3 Ask the MDS assistant
Questions about the procedure, storage, how long a filled tray keeps, the records to hold or one particular drug? Ask the assistant — guidance only.
What can go in, and what cannot
Only solid oral dose forms are repackaged. Whether a product is suitable depends on how stable it is outside its own container, on how toxic it is, and on the risk of cross-contamination.
Can go in
- Film-coated and uncoated tablets
- Hard and soft capsules, caplets, sugar-coated tablets
- Whole, or split where the form allows it
- Light-sensitive or hygroscopic products: in their primary packaging (telling the patient to remove it before taking the dose) or in an amber tray
Must stay out
- Oral liquids (syrups, drops, eye baths)
- Granules and powders
- Topical products (creams, ointments, emulsions, patches)
- Inhaled (sprays), nasal, rectal (suppositories), vaginal (pessaries) and sterile products
- Effervescent, sublingual and orodispersible tablets, and unstable light-sensitive products
- Modified or prolonged release tablets and capsules (they cannot be split)
- Heat-sensitive products (fridge storage, 2-8 °C)
What cannot go in is given separately and must appear on the label of the tray, so nobody assumes the tray is the whole treatment. When stability is in doubt, the Summary of Product Characteristics wins.
The service, step by step
- Indication and suitability. Three things have to hold: that it is indicated, that the medicines can be repackaged, and that the patient or carer can actually use it.
- Medication review. Before anything is filled, review the therapy and resolve what you find — interactions, duplicates, doses that could be dropped. Repackaging a bad regimen just makes it tidier.
- Consent and custody. The patient agrees to the service and to their medicines being held at the pharmacy to be prepared.
- Repackaging. At 15-25 °C and 40-60 % relative humidity, laid out by day and time, with batch, expiry and traceability recorded.
- Check they can use it. With a placebo tray, the patient or carer should be able to find and get out the dose for a given moment.
- Handover and labelling. Given out with the full label and the patient information leaflets.
- Follow-up. Reviewed regularly and updated whenever the prescriber or the patient reports a change.
Storage and how long it keeps
- While filling: 15-25 °C and 40-60 % relative humidity.
- The filled tray: somewhere cool and dry, between 8 and 25 °C, out of the light and away from moisture; do not refrigerate unless told to.
- How long the repackaging is good for: as a general rule, 2 weeks at most from leaving the original pack to the last dose taken. Longer needs stability data for that product.
- Outer limit (Royal Pharmaceutical Society): no more than 8 weeks repackaged without stability data.
- Expiry of the tray: never later than the earliest expiry of any medicine in it.
- Empty trays: stored for a year at most, out of direct sunlight and away from extremes (below 10 °C or above 50 °C).
What the label has to say
- The pharmacy, and how to contact it
- The patient's full name
- The day and time of each dose
- Name, strength and a physical description of each medicine
- Traceability: product code, serial number, batch and expiry
- An identifying number for the tray
- Medicines in the treatment that are not in the tray
- The period it covers (first and last date)
- How to use it and how to take the doses
- Storage warnings
- The patient information leaflets for the medicines inside
- Who prescribed it
If it does not fit on the tray, this information has to reach the patient another way — an instruction sheet, the leaflet or a QR code. For blind patients, include braille.
The legal side — Spain
- Authorisation: the pharmacy files a declaración responsable, signed by its owner, with the health authority of its autonomous community before starting the service.
- Not by third parties: only the owner of the pharmacy that dispensed the medicines may prepare and hand over the tray.
- Hazardous medicines: if cytotoxic or otherwise hazardous drugs have to be handled, the safe-handling guidance applies — and in practice they do not go into a tray at all.
- Disposal: single use; it goes back to the pharmacy and into the SIGRE collection point, which is the Spanish pharmaceutical waste scheme. Not in the bin and not down the sink. Elsewhere, use your own pharmaceutical waste route.
Frequently asked questions
What is a monitored dosage system (MDS)?
A monitored dosage system — also called a dosette box, a blister pack or a multi-compartment compliance aid — is a sealed tray in which a pharmacist repackages a patient's solid oral medicines, laid out by day and by time of day. It is a professional service that happens after dispensing: the pharmacist checks the therapy, repackages what can safely be repackaged, labels it and follows it up.
Which medicines cannot go into a blister pack?
Anything that is not a stable solid oral dose form: oral liquids, drops, sachets, effervescent, sublingual and orodispersible tablets, inhalers, patches, creams, suppositories, pessaries, eye and ear preparations, and anything injectable or kept in the fridge. Modified and prolonged release forms usually stay out too, because they cannot be split and their stability out of the original pack is often unknown. Warfarin and other drugs titrated to a blood result should not go into a fixed-dose blister at all.
Who is a candidate for an MDS?
Patients on several long-term medicines with several doses a day who are forgetting doses, or who have cognitive impairment, dexterity or eyesight problems, a complicated schedule, no support at home, or several different prescribers. The tool on this page scores those factors. But an MDS is not automatically the answer — see the question below.
Is an MDS always the right answer?
No, and this is worth saying plainly. The Royal Pharmaceutical Society's position is that a compliance aid should not be the first response to poor adherence: first find out WHY the patient is not taking their medicines. Often the better answer is a medication review that removes doses, a simpler regimen, larger-print labels, easier-open containers, a reminder chart or an alarm. An MDS also hides the original packaging and its patient information, makes it harder to spot what a tablet is, and takes pharmacy time every single cycle. Use it when it is genuinely the right intervention for that patient.
How long does a filled blister last, and how is it stored?
As a general rule, no more than 2 weeks from the moment the medicine leaves its original pack to the last dose taken; longer needs stability data for the specific product. The Royal Pharmaceutical Society sets 8 weeks as the outer limit for repackaged medicines without stability data. Keep the filled tray cool and dry, between 8 and 25 °C, out of the light and away from moisture, and never date it beyond the earliest expiry of any medicine in it.
Can I repackage modified or prolonged release capsules?
It is not recommended. Modified, prolonged and delayed release forms cannot be split, and once out of their original container their stability is often unknown. Check the Summary of Product Characteristics for the specific product, and if there is no data, leave it out and give it separately — noting on the label that it is part of the treatment but not in the tray.
Sources
- Royal Pharmaceutical Society. Guidance on the better use of multi-compartment compliance aids, and the 8-week outer limit for repackaged medicines without stability data.
- SEFAC — technical specification for monitored dosage systems (in Spanish). The criteria our dataset follows.
- CIMA — AEMPS. Official Summaries of Product Characteristics for the Spanish market: dose form, storage and stability. Elsewhere, use your own regulator's — in the UK, the electronic medicines compendium.
Every classification here is guidance. When in doubt the Summary of Product Characteristics wins, and so does your own judgement.