F – Formulations
There is a continuing need for pharmaceutical companies to manufacture age-appropriate medications for children. It is not just preferences for particular formulations that need to be considered, but also an appreciation of the physical and biochemical differences between children and adults (Batchelor and Marriott, 2015). ‘Paediatrics’ covers a wide age range, from neonates to adolescents, so their needs are also varied (Nunn and Williams, 2005). While it is understood that the oral route of drug administration is preferred for all ages, due to convenience and stability, many different forms can be considered. Oral liquids tend to be favoured in the lower age ranges, and can include many types (see Table 1). The volume of the oral liquid to be administered needs to be acceptable to the child; in children under the age of 4 years, the maximum recommended volume is 5 mL, where children between the ages of 4–12 years should not have doses exceeding 10 mL (Batchelor and Marriott, 2015).
Table 1. Different types of oral medications
| Type | Description |
|---|---|
| Solution | A fully combined mixture, where the solute is completely dissolved (e.g. oramorph) |
| Suspension | Where the components are not uniform and can separate, so often needs shaking prior to administration (e.g. amoxicillin) |
| Emulsion | Similar to suspension, but the components are immiscible (e.g. lotions, ointments and creams) |
| Syrup | A highly concentrated sugar solution – often manufactured specifically for children to mask the taste. Colouring agents are often used (e.g. cough syrup) |
| Drops | Either a solution or a suspension to be given by a calibrated dropper |
| Elixir | Similar to a solution, but sweetened with alcohol to help distribute drug particles (e.g. dexamethasone) |
Larger volumes of liquid (around 20 mL) are needed for dispersible tablets, and there is a danger for local tissue damage if correct volumes are not used, so smaller volumes and different formulations may be preferred, unless the liquid is dilute and the taste masked (Mistry et al, 2017). Chewable tablets and orodispersible formulations can also be considered – orodispersible tablets are designed to dissolve in the mouth, and can be convenient when not at home (e.g. Calpol Fastmelts), but the main limitation is the dose infiexibility. Taste receptors on the tongue will be activated, so taste masking again needs to be considered.
Conventional tablets are also limited by the specific dose: some tablets can be split, cut, or crushed, but this leads to inaccurate dosing and issues with licensing. Risks of choking and aspiration are increased (Khan et al, 2022), so the child's ability to swallow tablets needs to be explored. Studies show that children of varying ages are capable in swallowing tablets of different sizes (Batchelor and Marriott, 2015).
Training children to swallow tablets or capsules of varying sizes through play (Tse et al, 2020), or using sweets, can be incorporated into medicines management educational programmes, akin to teaching a child how to take an inhaler. ‘Pill schools’ have been shown to be effective in children as young as 3 years of age (Rashed et al, 2021). The impact on increased adherence in younger children taking tablets has not yet been explored, but the potential for a move away from unpalatable liquid formulations may be of benefit, particularly with other associated negative aspects, such as shorter expiry dates, the need for refrigeration, associated dental decay (Tse et al, 2020), and inaccurate dosing.
Multiparticulate dosage forms may be suitable for younger children (Roque, 2017), and are presented in sachets, or within a capsule which can be opened. The granules are usually mixed with liquid, or a soft food like yoghurt, as seen with hydrocortisone granules (Coope et al, 2021). This can improve swallowing and taste masking. Administering with food may promote adherence, although absorption and bioavailability may be altered (Khan et al, 2022).
Suitable formulations need to be considered on an individual basis, but the prescriber needs to consider dose volumes and size, safety aspects (such as the risk of aspiration), acceptability and taste (Nunn and Williams, 2005).
The next article in the series will be G – Gillick competence.