The MCA Stability Tool
The MCA Stability Tool (SPS page) provides recommendations on the inclusion of individual solid dose forms in multi-compartment compliance aids (MCAs). This involves transferring tablets or capsules from the manufacturers original packaging into MCAs.
Recommendations are based on the professional judgement of SPS Medicine Advice pharmacists following a review of the available evidence.
Suitability of MCAs
SPS does not endorse the routine use of MCAs. In line with RPS guidance on MCAs, the preferred option to support people taking their medicines is:
- dispense medicines in their original packaging
- provide appropriate pharmaceutical support
For some people, there may be no practical alternative to ensure safe medicine administration, and in such cases the use of MCAs may be necessary.
Decisions about including a medicine in MCAs should be patient-centred and based on professional judgement.
The MCA Stability Tool is designed to support, not replace, clinical decision-making and should be used alongside:
- local policies
- individual patient factors
- care setting
- practical handling requirements
Inclusion in MCAs should not rely on compatibility alone. The suitability of MCAs should be reviewed regularly.
Our article on Complex medication regimens: supporting adherence (SPS page) provides information on available interventions and tools.
Using the MCA Stability Tool in practice
Consider the following factors when applying information from the MCA Stability Tool.
Duration
Keep medicines in MCAs for the shortest time necessary. Generally, up to 5 weeks maximum, unless otherwise specified, or consider up to 8 weeks if the MCA is airtight i.e., sealed. Evidence on stability over time is limited, but if available, the MCA Stability Tool entry outlines the available data.
Type of MCA
Consider the type of MCA and assess which option is most suitable for the medicines being included and the suitability for the person.
Where available, the type of MCA described in stability data, for example, sealed and unsealed blister packs has been specified.
Multiple medicines in a compartment
The MCA Stability Tool gives recommendations of solid dose formulations in MCAs when stored individually. It does not take into account the impact of storing multiple medicines within the same compartment.
When you mix medicines in the same compartment, the RPS provides the following recommendations:
Capsules
Soft and hard gelatine capsules have a high-water content. Mixing gelatine capsules with tablets can lead to water transferring from capsules to tablets, which may impact chemical and physical stability. The impact of this is not known.
Avoid placing soft and hard gelatine capsules in the same compartment. There is a risk of moisture transfer between them, which may result in damage to the physical formulation, such as capsule brittleness, softening or distortion.
Modified-release formulations
Avoid mixing capsules with modified-release tablets. There is a risk the modified-release profile could be altered.
Medicines requiring additional clinical consideration
Use professional judgement when making decisions to include the following medicines in MCAs:
- medicines with severe consequences from loss of potency, such as carbamazepine
- narrow therapeutic index medicines
- ‘as required’ medicines
- medicines for acute use/conditions, such as flucloxacillin
- medicines where dose and strength vary, such as warfarin
- medicines that need to be taken in a very specific way, such as alendronic acid
- valproate-containing medicines must be dispensed in the manufacturer’s original packaging. Refer to the MHRA guidance on full pack dispensing of valproate containing medicines for further information
Monitoring
Consider the risk to the individual from potency loss or dose variability, particularly with unsealed MCAs. Monitor the person for any changes in therapeutic effect or increased adverse effects after MCA initiation.
How our content is generated
There is a lack of information on the stability of medicines in MCAs. The MCA Stability Tool content is generated through systematic research of our standard resources:
- Summary of Product Characteristics (SmPC)
- manufacturers stability data (when provided)
- Martindale
- American Hospital Formulary Service (AHFS)
- historical references
- primary literature studying the stability of medicines in MCAs
- UK and European Public Assessment Reports (Further information about UKPAR and EPAR)
The individual entries indicate which manufacturers’ SmPC the compatibility recommendation is based on. This recommendation is extrapolated to medicines of the same strength and formulation.
Limitations
When medicines are transferred from their original packaging into MCAs, manufacturers generally cannot guarantee their stability, safety, or effectiveness. In most cases, if this is done, it is considered off-label use.
For many of the medicines reviewed, there is no robust evidence available for their suitability in MCAs. Where relevant stability evidence is available, we have included a brief summary in the stability notes. Anecdotal information from historical references is considered low quality.
Primary literature studying the stability of medicines in MCAs does not always specify the type of MCA used. Where this information is available, it has been provided in the stability notes.
Using our advice
Compatibility rating
Compatibility ratings are assigned to medicines based on information found in the standard resources and the professional judgement of SPS Medicines Advice pharmacists. There are four compatibility ratings:
Compatible
Medicines suitable for use in MCAs, although use is likely to be off-label.
Stability data may be available to support use in MCAs but often the data is not available. Manufacturers may not specify suitability for storage in MCAs.
Monitor for any changes in therapeutic effect or increased adverse effects after MCA initiation.
Use with caution
Medicines deemed theoretically compatible for use in MCAs, but concerns about their stability exist. Use is likely to be off-label.
Special storage precautions are recommended to mitigate risks of drug degradation and reduced drug efficacy. Stability data to support use in MCAs is often not available and monitoring for changes in therapeutic effect, or increased adverse effects is recommended.
Incompatible
Medicines not suitable for use in MCAs due to stability concerns, such as being hygroscopic, light sensitive or temperature sensitive for example, fridge products.
Formulations such as buccal, chewable, dispersible, effervescent, orodispersible, soluble and sublingual tablets, soft capsules are usually not recommended in MCAs.
Medicines with associated handler risks, such as cytotoxics, are generally not recommended in MCAs. Do not halve or quarter tablets, as there are no stability data for this in MCAs.
No stability information
These medicines have not been reviewed by SPS and therefore a recommendation on suitability in MCAs is not given.
Stability notes
Stability notes below each medicine entry provide special storage precautions and actions to mitigate risk of drug degradation in MCAs. We have indicated in the stability notes the evidence available in the literature, or lack of, for example, ‘No stability data in MCAs available’.
The most common precautions are related to light and moisture.
Light
Protect from light
Store away from direct light. This precaution is based on SmPCs or other standard resources recommending to ‘protect from light’ but lacking further guidance.
Light sensitive medicine
A higher level of caution is needed compared to ‘protect from light’. Store in a light-resistant bag or a dark cupboard. These medicines are noted in the standard resources to have specific light stability issues, or there is a recommendation in the SmPC to store in the original container to protect from light.
Very light resistant medicine
These medicines are unstable when exposed to light. They are incompatible in MCAs as the risk cannot be mitigated.
Moisture
Protect from moisture
Do not store the MCA in high humidity areas such as bathrooms and kitchens. This precaution is based on SmPCs or other standard resources recommending to ‘protect from moisture’ but lacking further guidance.
Moisture sensitive medicine
A higher level of caution is needed compared to ‘protect from moisture’. Store in an airtight and waterproof (hermetically sealed) MCA. These medicines are noted to have specific moisture stability issues based on the standard resources.
Very moisture sensitive medicine
These medicines are unstable when exposed to moisture. They are likely to be incompatible, as the risks cannot be mitigated, such as the requirement of a desiccant.
Provenance notes
The provenance notes in the individual entries indicate which manufacturers’ SmPC the compatibility recommendation is based on, in addition to our standard reference resources.
Useful resources
Principles that support safe, person-centred decisions about monitored dosage systems (MDS) are discussed in the GPhC article on MDS.
Involving patients in decisions about prescribed medicines and supporting adherence are set out in NICE Clinical Guideline on medicines adherence.
Useful information on supporting people in taking their medicines and use MCAs can be found in the RCPharm Guide on MCAs (access to RCPharm members only).