Child-proof closures of pharmaceutical products: safety and usability

Safety and efficiency are paramount to ensure the quality and effectiveness of the products. One of the crucial aspects in achieving these goals is the use of reliable and certified systems, such as child-proof' closures for medicines which can ensure the integrity of medicines and at the same time guarantee correct use by all patients.

Of the types of closures available on the market, 'child-proof' closures - thanks to a special mechanism that inhibits opening by toddlers - are considered to be the safest and are usually applied to prevent risks associated with unintentional intake of medication.

Definition of child-proof closure and differences with other types

Child-proof packaging, also referred to as child-resistant (CRC), is by definition packaging that is difficult for a child under the age of 5 to open, but at the same time easily used by an adult.

Compared to the simpler 'screw-on' caps, which can be opened with a simple twisting motion, or the 'tamper evident' closures that make the first use of the product obvious, by law child-proof ones must guarantee:

  • they cannot be removed by children under a certain age (5 years) but can be opened by adults over a certain age (70 years) or with dexterity or strength problems;
  • fairly complex mechanisms, such as the combination of pressure and rotation, but easily understood by an adult user;
  • presence of a durable security element, even after numerous openings and closures.

In addition to these details , the closures must of course meet the requirements for pharmaceutical primary packaging and ensure:

  • material compatibility: it is necessary to choose closures with certified compatibility with the container material and the pharmaceutical product. This ensures integrity of the product.
  • Protectivebarrier: closures must provide a good barrier against moisture, oxygen and light. As some of the accessories that can be incorporated into the closures, specific components are also available to increase the level of insulation and protect the product from external agents. This is the case with liners, thin discs that are placed between the capsule and the bottle to provide extra protection, or silica gel, a material that reduces the negative effects of moisture.
  • Regulatory compliance: the use of regulatory compliant closures is essential to ensure the safety of pharmaceutical products.

Child-proof opening mechanisms

Most of these caps have a locking mechanism in addition to the standard opening or closing mechanism. The three most popular mechanisms are: 'Turn and Lift', 'Push and Turn' and 'Squeeze and Turn'.

One of the most common child-proof closures is 'Push and Turn'. It consists of two pieces: an upper cap and an inner cap. Both pieces have serrated edges that match each other, similar to two gears that are not engaged. When you simply turn the cap, without any pressure, these two gears will rotate without touching and the cap will continue to rotate without detaching from the container. By applying downward pressure, the 'gears' engage and can then rotate together, allowing the container to be opened.

The child-proof locking mechanism can also be combined with the most common oral drug dispensing systems, such as droppers or pipettes, which are necessary for accurately withdrawing and dispensing small quantities of liquid products. Child-proof closures are also suitable for sealing systems for the administration of paediatric syrups, such as the Safe&Easy kit, consisting of a bottle and a syringe, which can be joined together by a special reducer.

Child-proof packaging regulations

The regulatory references for the production of child-proof packaging come from UNI - Ente Nazionale Italiano di Unificazione, which draws up standards developed by technical bodies and promotes their harmonisation and dissemination worldwide and in Europe. In particular, consideration must be given to

  • UNI EN ISO 8317:2016 - 'Child-proof packaging - Requirements and test procedures for resealable packaging'.
  • UNI EN 14375:2016- 'Non-resealable child-proof packaging for pharmaceutical products - Requirements and testing'. It defines the characteristics that resealable packaging must have before being placed on the market and covers solvents, household cleaning products, strong acid or alkaline preparations, substances used for gardening and all substances that may be hazardous or carcinogenic.
  • UNI EN ISO 13127:2012 - 'Packaging - Child-proof packaging - Mechanical test methods for child-proof resealable packaging systems'. It specifies methods for performing mechanical tests on child-proof resealable packaging. The data generated by these methods are used to compare the characteristics of child-proof resealable systems. The document supports manufacturers in designing packaging that is safe and resistant to opening.
  • UNI CEN/TR 16353:2013 - 'Packaging - Safety guidelines for flexible plastic packaging to minimise the risk of choking children'. It addresses the safety of flexible plastic packaging.

The new frontiers of child-proof closures

Although the child-proof closure mechanism is widely used, considered effective and has undergone very little development since it was first launched on the market, this type of packaging is also influenced by the innovations brought about by so-called 'digital healthcare'.

In particular, research is focusing on finding solutions that best combine the need for safety and security with that of usability, going beyond the purely mechanical characteristics of child-proof closures. A new solution is ID-cap, a capsule with integrated biometric recognition which allows the patient to easily open the product by fingerprint reading and a simple twist of the cap. The item is also designed to be used via a dedicated app, which allows not only opening but also effective monitoring of the treatment.

The biometric locking system represents a significant step forward that the packaging of pharmaceutical products is taking towards users, guaranteeing them therapy and dispensing perfectly adapted to their needs.