Why children need different medicine formulations

Children are not simply small adults, and this is especially true when it comes to how their bodies process medicines. Giving an adult medication to a child by merely cutting the dose or crushing a tablet can lead to ineffective treatment or harmful side effects. Paediatric patients—ranging from premature newborns to adolescents—have distinct physiological characteristics that require specially designed medicine formulations. These formulations account for differences in metabolism, organ maturity, and the practical challenges of administering medicine to a child who cannot safely swallow a standard pill.

Dosing by weight and developmental stages

A child's medicine dose is generally calculated based on their body weight or, in some cases, their body surface area. This ensures the amount of active ingredient is appropriate for their physical size. However, weight alone does not dictate how a child will process a drug. A child's liver and kidneys—the primary organs responsible for metabolising and clearing medicines—are still developing. In premature infants and neonates, these organs may process drugs much more slowly than an adult's, necessitating lower concentrations and careful monitoring.

Conversely, toddlers and young children sometimes metabolise certain medicines faster than adults, meaning a standard adult dose adjusted for weight might leave their system too quickly to be effective. Furthermore, children process inactive ingredients (excipients) differently. Some preservatives or alcohols that are safe for adults can be toxic to newborns. Because of these developmental variables, dedicated paediatric clinical trials are essential to determine safe and effective dosing across different age bands.

Liquids, granules, and dispersible tablets

Adult tablets and capsules are often impractical and potentially dangerous for young children due to the risk of choking. To address this, manufacturers develop paediatric-specific formulations such as liquids (solutions and suspensions), powders or granules that can be mixed with small amounts of food or liquid, and chewable tablets. Palatability is another major factor; if a medicine tastes bitter or unpleasant, a child is likely to spit it out, reducing the actual dose received and risking treatment failure.

Dispersible tablets are particularly vital in global health. These are designed to disintegrate rapidly in a small amount of water, creating a liquid that is easy to swallow and can be accurately measured to match a weight-based dose. They also tend to be more stable in hot, humid climates than liquid formulations, which often require refrigeration or have shorter shelf lives. For liquid medicines, accurate dosing devices like oral syringes are crucial, as household spoons are notoriously inaccurate.

The WHO 'Make Medicines Child Size' initiative

Recognising a historical global gap in appropriate paediatric medicines, the World Health Organization (WHO) launched the 'Make Medicines Child Size' initiative. This campaign aims to raise awareness and encourage pharmaceutical companies and governments to prioritise the research, development, and production of medicines tailored specifically to children's needs. Before this push, many healthcare providers had to improvise by crushing adult tablets or estimating fractions of a dose—a practice known as off-label prescribing, which carries significant safety risks.

The initiative highlights the urgent need for child-appropriate formulations of medicines used to treat high-burden diseases in low- and middle-income countries, such as malaria, tuberculosis, and HIV. It also advocates for regulatory changes, prompting many national authorities to require specific paediatric investigation plans before approving new medicines that might be used in children.

The WHO Model List of Essential Medicines for Children

To guide countries and healthcare providers, the WHO maintains a separate Model List of Essential Medicines for Children (EMLc). First published in 2007 and updated every two years, the EMLc lists the minimum medicine needs for a basic healthcare system specifically targeting children up to 12 years of age. Crucially, it specifies the preferred formulation for each medicine—such as recommending a dispersible tablet over a standard solid pill where appropriate.

The EMLc serves as a benchmark for national medicine policies, public procurement systems, and clinical guidelines worldwide. In South Africa, the national Essential Medicines List for children draws heavily on these WHO recommendations, and the South African Health Products Regulatory Authority (SAHPRA) requires specific safety, efficacy, and quality data before registering any paediatric formulation. Patients and caregivers can use tools like HealthSA to verify the registration status of medicines in South Africa, ensuring they meet these strict regulatory standards.