As time swiftly passes, our AGePOP project is nearing its conclusion. Now is the perfect moment to reflect on the valuable insights we’ve gained over the past four years.

We had the support of almost 800 older adults and more than 300 young healthy volunteers across the different studies within the AGePOP project. We extend our heartfelt gratitude to all participants! Their contributions have enabled us to deepen our understanding of gastrointestinal physiology and gather significant knowledge about pharmacotherapy in older adults and geriatric patients. Their participation has greatly contributed to the advancement of science for the benefit of society.

Despite this encouraging fact, there are also several challenges that geriatric patients face when participating in clinical studies. One factor that significantly hinders the participation of older adults and geriatric patients in clinical studies is the high prevalence of polypharmacy within this age group. The complexities associated with taking multiple medications often lead to the exclusion of these patients from clinical studies, as co-medications may confound the study results. Our research clearly demonstrated that the prevalence of polypharmacy – defined as the intake of five or more medications – varies depending on the setting. Results from two different studies in Germany showed that the prevalence in a hospital is around 96%% [1, 2], while it was 59% in the home settings [2]. This also indicates that multimorbid patients often require more medical support compared to their healthier counterparts.

With respect to oral dosage forms, older adults prefer solid forms (e.g., tablets) over liquid forms (e.g., syrups) [2] and find tablets easier to swallow than capsules [3]. Research comparing the swallowability, visual perception, and handling of tablets demonstrated that both young and older adults can swallow a wide variety of tablets of different sizes and shapes, although they tend to underestimate their own swallowing abilities [3]. The primary factor affecting the subjective rating of swallowability is the tablet’s size, followed by its shape and surface characteristics. The significance of surface characteristics was highlighted in a study examining the effects of different surfaces on esophageal transit, a crucial factor for the safe and efficient administration of solid oral dosage forms. The study demonstrated a clear advantage of film-coated tablets over uncoated tablets and hard gelatin capsules in facilitating esophageal transit [4]. Overall, we observed that swallowability significantly impacts the willingness to take tablets regularly, especially over longer time periods [1].

In addition to evaluating the acceptability of solid oral dosage forms, we conducted questionnaire-based studies to explore the real-life dosing conditions in this patient population. Generally, older adults typically take their medications immediately after a meal and tend to take all their medications together (49%) rather than separately (28%) [2, 5]. The volume of liquid typically used to swallow the medication is quite variable (see Figure 1). The majority of older adults take their medicine with a small glass (100 mL, 32%), a few sips (50 mL, 28%), and a larger glass (200 mL, 25%) of liquid. While the majority of individuals use tap or mineral water (55%), some also use sparkling water (32%), tea (19%), or other drinks for taking their medicine (details are presented in Figure 2) [2, 5]. Additional studies have demonstrated that the use of sparkling water and black tea could influence the pharmacokinetics of drugs in certain cases [6, 7].