Smart packaging in clinical trials: what it means, what it measures, and what to plan for

Smart packaging in a clinical trial context means drug packaging or dispensing devices that usually contain electronics capable of recording medication events. The point is to digitise dispensing or packaging opening, converting it to an objective record rather than relying on what patients report afterwards or counting pills in a returned bottle. The term can cause some confusion, partly because the packaging industry uses it for several unrelated technologies, like temperature or regulatory compliance monitoring, and partly because the methods sold under this label differ considerably in what they actually measure. This page helps define the term as it applies to adherence monitoring in trials and separates it from the supply chain technologies it tends to get conflated with. It explains a distinction between measurement methods that is worth understanding before comparing any of them, which is whether the data capture requires the patient to do anything beyond taking their medicine.

What smart packaging means in an adherence context

In the adherence monitoring literature these technologies usually appear under the heading of digital adherence technologies, sometimes shortened to DAT, and the packaging-based subset includes smart blister packs that detect when a tablet is pushed through the foil, smart bottles and caps that detect when a container is opened, and smart dispensers that release and count individual doses. Connected inhalers and injector pens belong to the same family for other dosage forms, although this page concentrates on solid oral medication because that is where the packaging vocabulary and the adherence vocabulary overlap most. What these devices have in common is that they generate a timestamped record of a medication event at the point where the dose leaves its packaging, and that record then feeds into the trial’s adherence dataset without anyone having to fill anything in. A fuller comparison of the methods available for measuring adherence, including the ones that are not packaging based, is covered in our guide to adherence monitoring in clinical trials.

What smart packaging is not

The same phrase is used across the pharmaceutical supply chain for technologies that have nothing to do with adherence, and a supply or packaging professional searching the term will meet all of them mixed together. Serialisation, which assigns a unique identifier to each saleable unit under regulations such as the FMD in Europe and the DSCSA in the United States, exists to prevent falsified medicines entering the supply chain, and it tells you nothing about whether a patient took a dose. RFID and barcode track-and-trace systems answer the question of where a product is between the manufacturing site and the depot or pharmacy, which is a logistics question rather than a clinical one. Temperature indicators and cold chain data loggers record the conditions a product has been stored in, which matters a great deal for product quality and not at all for adherence. All three of these are sometimes marketed as smart packaging, and all three are useful, but they monitor the product rather than the patient, and a trial that needs adherence data will not get it from any of them.

Active and passive measurement, and why the difference matters more than the hardware

Once the supply chain technologies are set aside, the remaining adherence measurement methods divide along one axis that is more useful than any comparison of features. Some methods require the patient to perform a task beyond taking the dose, such as completing an entry in an electronic diary, confirming a dose in an app, or recording a video of themselves swallowing a tablet, and these are usually described as active methods. Other methods capture their data as a by-product of the dosing action itself, because the electronics sit in the packaging or the dispenser and the record is generated when the patient does the thing they were going to do anyway, and these are described as passive methods.

An adherence measurement method that requires patient effort measures adherence to the measurement task, and infers adherence to the medication from it. The inference fails in both directions. A completed diary entry does not demonstrate that a dose was taken, and the best known evidence for this is a study of paper diaries fitted with concealed sensors (Stone et al., BMJ, 2002) in which patients reported completing their diaries at the correct times around ninety per cent of the time while the sensors showed they had genuinely done so around eleven per cent of the time. A missing entry, meanwhile, does not demonstrate that a dose was missed, because the patient may simply have skipped the reporting task, and the dataset has no way of telling the two situations apart.

The second problem with active methods is quieter and arguably more serious. The missing data they produce is not spread evenly across the study population, because willingness to complete a daily reporting task and willingness to take a daily medication are related behaviours, and the patient who has stopped filming or logging their doses is disproportionately likely to be the patient who has stopped taking them. A statistician would describe this as data that is missing not at random, and the practical consequence is that active methods lose their coverage in precisely the group of patients the trial most needs to observe. This is one of the reasons self-reported adherence consistently comes out higher than adherence measured electronically when the two are compared in the same study, a pattern that has been replicated many times in the literature.

Honesty requires saying what passive packaging-based methods do not measure either, which is ingestion. A dispensing record shows that a dose left the device at a given time, and only directly observed therapy or an ingestible sensor can confirm that it was swallowed, so a trial that genuinely needs ingestion confirmation for a small number of patients has legitimate reasons to accept the burden those methods carry. For most studies the more useful question is what kind of error a method produces, because the residual gap between dispensing and ingestion is small and roughly random across patients, while the gap in an active method is systematic and points in the flattering direction. The related question of what an opening event proves compared with a dispensing event, which matters when comparing caps and bottles against dispensers, is dealt with separately in our guide on smart pill bottles and what opening data shows.

Translating the vocabulary

Readers arriving from the clinical supply side often use different words for the same underlying concepts, so the table below maps the packaging vocabulary onto the adherence terms used across the rest of our guides.

Packaging term	What it usually refers to	Adherence concept and where we cover it
Smart packaging, connected packaging	Any packaging with embedded electronics	Packaging-based adherence monitoring, this page
Digital adherence technology (DAT)	The umbrella category including apps and devices	Method comparison
Smart blister	Blister pack detecting push-through events	Event-based monitoring
Smart bottle, smart cap	Container detecting opening events	Opening versus dispensing
Smart dispenser	Device releasing and counting individual doses	Dose-level monitoring
Adherence data, compliance data	The dataset these devices produce	Acting on the data during a live trial

What supply teams need to plan for

Introducing a monitored device into a study changes some familiar parts of the clinical supply workflow, and it is easier to accommodate them at protocol and kitting design stage than after the supply plan is fixed. Kitting is the first consideration, because a device either replaces the standard container or attaches to it, and the kit design needs to account for which of these applies, whether the device ships assembled with the drug or is fitted at site, and how many spares each site should hold. Labelling follows from that, since the investigational medicinal product label requirements still apply to the primary container, and the instructions for use for the device need to travel with the kit in the trial languages, which has lead time implications that are worth raising with the label vendor early. Device provisioning is a workflow that traditional supply plans do not include at all, covering how each device is associated with a patient identifier at dispensing, how sites confirm the device is transmitting before the patient leaves, and who handles a device swap if a unit fails mid study. Returns and reconciliation change shape as well, because alongside the usual accountability of unused medication there is now a reusable device to recover, inspect, and either redeploy to the next patient or hold for the next study, and the reconciliation itself becomes easier in one respect, since the device record of doses dispensed gives the site a count to reconcile against rather than an estimate built from returned tablet counts alone. None of this is onerous, but each item benefits from appearing in the supply plan as a line item rather than surfacing as a question during site initiation.