Zastaprazan belongs to a relatively new class of medicines called potassium-competitive acid blockers, or P-CABs. Unlike proton pump inhibitors, which require specialized cellular mechanisms to suppress gastric acid, P-CABs act by blocking the potassium channel involved in acid secretion in the stomach’s parietal cells. The class has attracted interest because it can produce a faster and potentially longer-lasting rise in gastric pH than conventional acid suppression. Zastaprazan, developed in Korea, is already available as a standard tablet for acid-related disorders, including reflux esophagitis and peptic ulcer disease.

The new formulation was designed to disintegrate on the tongue, allowing it to be swallowed without water while an orange-flavored excipient improves palatability. Such dosage forms could offer practical advantages for people who have difficulty swallowing conventional tablets, including some older adults and patients with dysphagia, nausea or vomiting, or situations in which access to water is restricted. The trial also addressed a specific concern about disintegrating tablets: because the drug dissolves in the mouth, it might theoretically be absorbed through the buccal mucosa and enter the bloodstream faster than a tablet swallowed whole. The data did not show such an early exposure advantage.

Researchers conducted the open-label, randomized, single-dose study at the Biomedical Research Institute of H+ Yangji Hospital in South Korea. Participants were assigned in equal numbers to six treatment sequences, with each person receiving all three formulations in a different order. A one-week washout separated dosing periods, and all administrations occurred after an overnight fast under standardized conditions. Blood was sampled frequently during the first hours and then at intervals extending to 36 hours, allowing investigators to characterize both rapid absorption and the later elimination phase. Fifty-one participants completed all three periods; three withdrew after the first because of scheduling conflicts, and none left because of an adverse event.

Plasma concentrations of zastaprazan and its major circulating metabolite, M1, were measured with a validated liquid chromatography–tandem mass spectrometry method. The primary pharmacokinetic endpoints were maximum plasma concentration, or Cmax, and area under the concentration-time curve to the last measurable concentration, AUCt, which together describe systemic exposure. An analysis of variance on log-transformed values was used to calculate geometric mean ratios and 90% confidence intervals. Bioequivalence required all confidence intervals for these two primary measures to fall between 80% and 125% of the conventional tablet’s exposure, the standard acceptance range used in comparative bioavailability studies.

Both administration methods for the disintegrating tablet met that threshold. Without water, its Cmax was 95.05% of the conventional tablet, with a 90% confidence interval of 88.38% to 102.21%, while its AUCt was 108.00%, with an interval of 100.50% to 116.06%. When taken with water, the disintegrating tablet produced a Cmax ratio of 90.85%, with an interval of 84.96% to 97.16%, and an AUCt ratio of 101.88%, with an interval of 96.69% to 107.36%. The active metabolite M1 also had comparable exposure under both conditions, with its confidence intervals inside the same bioequivalence range. These results indicate that changing the dosage form did not materially alter how much zastaprazan reached the bloodstream or how quickly it was cleared.

The detailed absorption measures pointed in the same direction. Median time to peak concentration was 0.667 hours for the conventional tablet, 0.833 hours for the disintegrating tablet without water and 0.667 hours for the disintegrating tablet with water. Mean absorption rate constants were 1.41, 1.19 and 1.60, respectively, indicating no clinically meaningful formulation-related shift in absorption. The apparent elimination half-life was approximately nine hours across treatments, while apparent clearance and apparent volume of distribution were also similar. The investigators found no evidence of unusually rapid systemic entry after oral disintegration, including in an exploratory analysis of the active metabolite.

Safety monitoring found two mild treatment-related laboratory abnormalities in a single participant after the conventional tablet: one positive urine test for red blood cells and one for white blood cells. Neither was accompanied by symptoms, both were judged mild, and both resolved without specific treatment. No adverse drug reactions were reported after either administration of the disintegrating tablet, and no clinically meaningful changes were detected in vital signs, laboratory measures or electrocardiograms. The absence of new safety concerns is consistent with earlier healthy-volunteer data on conventional zastaprazan, which also reported no serious adverse events and only mild reactions such as headache and dyspepsia.

The findings support the disintegrating tablet as a potential alternative for people who cannot comfortably swallow a conventional tablet, but the trial’s design limits how broadly the result can be applied. It examined a single 20 mg dose in healthy young men under fasting conditions, rather than repeated dosing in older adults or patients with swallowing difficulty. People most likely to benefit may also have cancer, cardiovascular or cerebrovascular disease, and their conditions or concomitant medicines could affect drug absorption and safety. Research in the intended patient populations will therefore be needed to confirm that the formulation’s convenience translates into practical clinical benefit. Subject to that qualification, the study provides evidence that a water-free, orange-flavored version of zastaprazan can deliver the same systemic dose as the established conventional tablet without introducing a new safety signal.

Subject of Research: Pharmacokinetic bioequivalence and safety of orally disintegrating zastaprazan tablets in healthy adults

Article Title: Comparative Pharmacokinetics and Safety of Orally Disintegrating and Conventional Tablet Formulations of Zastaprazan in Healthy Subjects

Article References: Kim, H.-G., Kang, S., Min, S., Hong, H., & Bae, M. (2026). Comparative Pharmacokinetics and Safety of Orally Disintegrating and Conventional Tablet Formulations of Zastaprazan in Healthy Subjects. Pharmacology Research & Perspectives, 14(6), Article e70337. https://doi.org/10.1002/prp2.70337

Image Credits: AI Generated

DOI: 10.1002/prp2.70337

Keywords: zastaprazan, orally disintegrating tablets, bioequivalence, pharmacokinetics, acid suppression, potassium-competitive acid blockers, gastroesophageal reflux, drug formulation, clinical trials, patient adherence, Comparative, Safety

The study, led by Suzanne M. Debeij of Leiden University Medical Center and colleagues, is part of a larger multicentre cohort project called Better@Home, which followed 110 patients across eight Dutch geriatric rehabilitation centres. For the sensor sub-study, the researchers recruited 26 patients from a single rehabilitation centre in an urban area, along with nine care professionals, most of them physical therapists. The participants were typical of the geriatric rehabilitation population: the median age was 77 years, roughly six in ten were women, and most lived alone. Their reasons for rehabilitation ranged from elective orthopaedic surgery and trauma to respiratory disease, and they spent a median of about 25 days as inpatients followed by roughly 46 days of home-based rehabilitation.

The technology at the heart of the study was the Hipper sensor monitoring system, a hip-worn device containing a three-dimensional accelerometer that samples movement 12.5 times per second and produces an activity output every minute. That output is expressed as a Physical Activity Measure, or PAM score, which reflects the amount of body movement recorded and can be converted into metabolic equivalents for analysis. Data travel wirelessly from the sensor to a Raspberry Pi-based transmitter and then to web dashboards accessible to both patients and care professionals. Crucially, the system was not just a measurement tool: therapists were expected to use the data to coach patients about their movement behaviour, often during regular therapy sessions. Three versions of the sensor were used during the study period, including an updated prototype that provided minute-by-minute rather than 15-minute output and required redesigned dashboards.

The researchers assessed usability and feasibility using a mixed-methods design. A focus group with the care professionals was structured around the User Experience Honeycomb model and analysed with the qualitative Framework method, while patients completed interviewer-administered surveys at admission and after discharge. Quantitative adherence came from the sensors themselves, with wear days counted as a measure of how consistently the system was actually used. This triangulation allowed the team to compare what professionals and patients said about the technology with what the devices recorded in practice.

The adherence numbers were striking. Twenty-three patients wore the sensor during inpatient rehabilitation for a median of 11 days, corresponding to 100 percent of the days the sensor was offered. During home-based rehabilitation, 19 patients used the device, wearing it on 96.6 percent of the days it was available. For a population characterised by frailty, multimorbidity, and often some degree of cognitive impairment, those adherence rates are remarkable and suggest that, at a basic level, the system worked as intended. The researchers concluded that feasibility — the extent to which the digital health system functions as intended — was sufficient, though they caution that high adherence may partly reflect compliance with clinician instructions rather than genuine engagement with the technology.

What the sensors recorded, however, was sobering. During inpatient rehabilitation, patients spent a median of 93 percent of their waking day — about 666 minutes, or more than 11 hours — in sedentary behaviour. At home, the proportion dipped slightly to 90.5 percent, but because total wear time increased, the absolute sedentary time actually rose to a median of about 704 minutes per day. Time spent in moderate-to-vigorous physical activity was essentially zero in both settings, at 0.0 percent of waking time, while light physical activity accounted for only about 7 percent in hospital and roughly 10 percent at home. The pattern of sedentary bouts did shift between settings: patients had more frequent but shorter sedentary episodes at home, and time spent in uninterrupted bouts longer than an hour decreased by nearly 48 minutes.

These findings matter because prolonged sedentary behaviour is not a benign habit. It is associated with increased risk of non-communicable diseases and all-cause mortality, even in older adults who meet recommended physical activity guidelines, and it may delay functional recovery, worsen deconditioning, and increase dependency in daily activities. Both total sedentary time and long, uninterrupted sedentary bouts contribute to the harm. For frail older patients, simply breaking up sitting with short, low-effort movements may be a more realistic starting point than pushing them toward higher-intensity exercise — which is precisely the kind of behavioural nudge that monitoring-and-feedback systems are designed to deliver.

Yet the qualitative data revealed why the system struggled to fulfil that promise. Care professionals valued the sensor as a conversation starter that opened meaningful, motivational discussions and offered insight into when and how intensely patients moved — one therapist described being able to see whether a patient practised all morning and then did nothing in the afternoon. But they were troubled by the opacity of the PAM score, which patients could not interpret, and by perceived measurement inaccuracies that eroded trust in the data. One physiotherapist recounted a patient who was offended when the sensor failed to record her climbing the stairs, even though she had been working hard. The denser data streams from the updated sensors made the dashboard graphs more complex and harder to interpret, and practical frictions — the risk of losing the device, logistical hurdles, and the many steps required to enrol and transfer patients between settings — further impeded integration into clinical workflows.

Patients echoed many of these concerns. Thirteen of the fifteen who answered the sensor-related survey questions said the system offered them no added value, and only seven said they fully or partially trusted the sensor. Some were unsure why they were wearing it at all, with answers ranging from “for research” to “I don’t know, I’m in a wheelchair.” Nearly half reported that their care professionals did not provide adequate support, and several wished they could review the results together with a therapist. Still, the picture was not uniformly negative: eight patients found the system easy to use, five said they would recommend it, and one noted that it created a sense of external accountability for staying active.

When asked what a better intervention would look like, the professionals were clear: it should be easy to use, have a clearly defined objective, incorporate technology that provides direct visual or tactile feedback, and show patterns, intensity, type, and timing of activity over time. They also stressed preconditions that go beyond the device itself — educating patients and informal caregivers about the risks of sedentary behaviour, conducting a pre-implementation analysis of needs and available technology, involving the entire multidisciplinary team, and cultivating a rehabilitation climate that invites and makes it safe to be physically active, with staff acting as role models. The study’s authors conclude that sensor-based feedback in geriatric rehabilitation can indeed be feasible and valuable, but only if measurement accuracy improves, the technology is tailored to individual patient goals, its added value becomes evident to users, and support is provided to both patients and professionals. In other words, the hardware may be ready; the harder engineering challenge is human — designing eHealth that fits the routines, abilities, and motivations of the older adults and clinicians it is meant to serve.

Subject of Research: Usability and feasibility of wearable sensor-based feedback on sedentary behaviour in geriatric rehabilitation

Article Title: Usability and feasibility of a wearable sensor-based monitoring system providing feedback on sedentary behaviour during inpatient and home-based geriatric rehabilitation

Article References: Debeij, S. M., Haaksma, M. L., de Waal, M. W. M., van Haastregt, J. C. M., Pol, M. C., Kasteleyn, M. J., & van Dam van Isselt, E. F. (2026). Usability and feasibility of a wearable sensor-based monitoring system providing feedback on sedentary behaviour during inpatient and home-based geriatric rehabilitation. European Geriatric Medicine. https://doi.org/10.1007/s41999-026-01616-6

Image Credits: AI Generated

DOI: 10.1007/s41999-026-01616-6

Keywords: wearable sensors, sedentary behaviour, geriatric rehabilitation, eHealth, physical activity, older adults, feasibility, usability, behaviour change, digital health, home-based rehabilitation, patient adherence