Small patients, higher stakes: why taste in pediatric drug formulations demands more from formulators

• Taste plays a critical role in whether children accept oral medicines, with direct implications for treatment adherence and clinical outcomes. Yet designing palatable pediatric drug formulations remains one of the more demanding challenges in pharmaceutical development.
• From biological differences in how children perceive bitterness to dosage form constraints and strong regulatory guardrails, formulators face a unique set of considerations when developing oral medicines that are safe, effective, and palatable enough for young patients.
• Read on for insights from dsm-firmenich’s taste experts on the key scientific, formulation, and regulatory considerations behind improving taste in pediatric drug formulations.

An adult who finds the sensory experience of a medicine unpleasant can often tolerate that discomfort because they understand the therapeutic benefit. Whereas a child may not have the same ability to accept an unpleasant taste or texture. The result is often refusal, spitting out, or missed doses, potentially compromising dosing accuracy, treatment adherence, and ultimately clinical outcomes – coupled with parental frustration.

These consequences carry particular weight in pediatric drug formulations. Children are among the most vulnerable patient populations, with developing physiologies, age-dependent responses to medicines, and a limited ability to communicate or tolerate discomfort. The science tells us that they are also among the most physiologically sensitive to aversive tastes, compounding the challenge for formulators, who must address palatability alongside strict safety, quality, and regulatory expectations.

We asked dsm-firmenich taste experts Carlos Almasqué, Global Marketing Director, Pharma Excipients, and Pierre-Louis Bardonnet, Pharm.D, Ph.D., Global Technical Business Development Manager, to share insights on how formulators can develop more patient-centric oral medicines for children.

Children and infants do not experience taste the same way adults do

It is commonly understood that children find bitter tastes less acceptable than adults, but this is only part of the picture. Several key differences shape how they experience oral medicines. First, children have a higher density of taste papillae, the small structures on the tongue that house taste receptors.¹ More papillae mean extra receptor contact points per unit of surface area, which translates to a more intense sensory response to whatever is in the mouth.²

Furthermore, although the precise mechanisms are still being investigated, research shows that children are significantly more sensitive to bitter compounds than adults with the same genetic taste profile, suggesting that age itself modifies how bitter taste receptors function during childhood.³ Taken together, these factors mean that the bitter signal a child receives from an active pharmaceutical ingredient (API) is not just stronger - it may also be perceived differently than what an adult experiences with the same molecule.

“Sensory evaluation during the development of pediatric drug formulations typically relies on trained adult panels. While these do provide valuable and structured data on a formulation's taste profile, the biological gap between adult and pediatric taste perception means those results may not fully predict how a child will respond to the medication. This is why we at dsm-firmenich also draw on our broader understanding of pediatric taste biology, including what we know about receptor and sensitivity differences, to complement adult sensory panels and build a fuller picture of how a young patient is likely to respond.” - Pierre-Louis Bardonnet, Pharm.D, Ph.D., Global Technical Business Development Manager at dsm-firmenich.

Poor palatability is not an API challenge

Addressing palatability in any drug formulation typically starts with profiling the API - i.e. identifying which taste receptors it triggers and how intense the signal is. With more than 66% of APIs considered to be inherently bitter, this is already a widespread challenge.⁴ But how the API is delivered can have just as big an impact on how a patient experiences it, especially in pediatric dosage forms.

Because children often cannot swallow solid oral doses such as tablets, pediatric medicines are usually delivered as liquids, semi-solids, and dispersible formats. These dosage forms expose the API to taste receptors across a larger surface area in the mouth and for a longer duration than a tablet or capsule that is swallowed whole. A child's smaller oral cavity compounds this further: where an adult might take a single swallow, a child may need several, extending contact time with the API. The result is that the same molecule at the same concentration can present unique taste challenges depending on the delivery format -and may require a different taste modulation approach.

“When we work with customers on pediatric formulations, one of the first things we explore is how the dosage form itself will shape the taste experience. The API profile is the starting point, but the format determines how that profile is actually experienced in the mouth. By addressing both together through a taste strategy designed specifically for our customer’s unique needs, we can more effectively tackle palatability and develop medicines that are easier for these vulnerable patients to accept.” - Carlos Almasqué, Global Marketing Director, Pharma Excipients at dsm-firmenich.

Pediatric taste strategies require more than sweeteners or popular flavors

Sweeteners and flavoring are among the most widely used tools for improving the taste of oral medicines, as they are cost-effective and options available are broad. But in pediatric drug formulations, these approaches come with limitations that can restrict their effectiveness on their own. 

From a safety perspective, there is a high risk of over-palatability, for instance. In the late 1940s, the introduction of a candy-flavored aspirin in the US was followed by a significant increase in pediatric overdose cases, a cautionary precedent that still informs regulatory thinking today.^5,6 More broadly, the use of certain excipients in pediatric populations is subject to strict limits. This is because children's smaller body mass and developing metabolisms mean that ingredients considered safe in adult formulations may pose risks, or may only be safe at lower levels, in pediatric populations. As a result, the type and amount of sweeteners must be carefully justified.

Beyond these regulatory restrictions, the efficacy of simply covering unpleasant off-notes is limited by taste biology. When an API triggers multiple bitter taste receptors simultaneously, flavoring alone often cannot fully offset the aversive response, particularly in a child whose taste system is already amplifying the bitter signal. 

“Carefully balanced, multi-layered taste strategies are needed to address pediatric palatability. For example, we might combine bitter blockers to target specific taste receptors with masking agents to modify the overall taste profile of a solution. Another layer we apply is cognitive interference. Here, we use competing sensory inputs like sweetness or cooling to redirect the brain's attention away from bitterness. The key is understanding which combination is right for a given API and dosage form, helping formulators improve acceptance, while respecting the high safety and regulatory bar for pediatric drug products.” - Pierre-Louis Bardonnet.

Taste decisions should be considered early in pediatric drug development

In today’s pharma landscape, palatability can no longer be seen as a final refinement to be addressed once the core drug formulation is established. Both the European Medicines Agency (EMA) and the US Food and Drug Administration (FDA) now treat acceptability—including palatability—as a regulatory expectation in pediatric drug development.^7,8 The EMA’s guideline even specifies that a pediatric medicine's palatability should be satisfactory on its own merit, without the need to mix with food or drinks unless otherwise justified.⁷ A product that reaches late-stage development without adequate palatability data risks regulatory challenges at submission, on top of the reformulation costs and timeline delays that come with retrospective taste correction.

“Beyond the regulatory and commercial risks, every stage of development where palatability isn't considered is a missed opportunity to design a better experience for the child taking the medicine. We encourage our customers to involve taste experts early, ideally around Phase II once the safety profile is established. The earlier taste is integrated into the formulation strategy, the more options are available and the fewer compromises needed. This matters even more for pediatric drug formulations, where the margin for error is narrower.” - Carlos Almasqué.

Together elevating pediatric drug palatability

At dsm-firmenich, our taste experts work closely with pharmaceutical customers to address the complex challenges of pediatric palatability from the earliest stages of formulation design. By combining cutting-edge taste perception science, a broad portfolio of innovative flavors and taste modulation solutions, and end-to-end expert support, we help formulators create safe, effective, and palatable drug products that improve acceptance and support better treatment outcomes for this vulnerable patient group.