The increasing awareness of acceptability and usability of pharmaceutical drug products by the patient as a key quality requirement continues to drive need for integrating patient centric drug product design into the pharmaceutical development process. The complex matrix of multiple drug product related decisions during the early drug development process often limits patient-centric drug product (PCDP) design options in the final commercial drug product development phase. To integrate the specific needs and perspectives of patients into drug development and product design process, a rational approach integrated into the complex development matrix is required from the start and weighs product development decision options accordingly. The aim of this work was to develop a roadmap for PCDP design in a multidisciplinary approach that leads to better usability, adherence and acceptance of the drug by patients via early integration into the development matrix. The proposed rational approach is based upon regulatory requirements and lessons learned from pediatric and geriatric drug development.

Although knowledge on medicine acceptability remains fragmented, this multi-faceted concept has emerged as a key factor for compliance in pediatrics. In order to investigate the acceptability of medicines used in the University Medical Centre Ibn Sina (CHIS) of Rabat, Morocco, an observational study was conducted. Using a multivariate approach integrating the many aspects of acceptability, standardized observer reports were collected for 570 medicine intakes in patients up to the age of 16, then analyzed on a reference framework. Tablets appeared to be well accepted in children greater than 6 years old, but were crushed/dissolved for 90% of the 40 children aged from 3 to 5, and 100% of the 38 patients younger than 3. Moreover, the prescribed dose was fully taken for only 52% and 16% of these younger children, respectively. Despite this, tablets represented 24% of evaluations in children from 3 to 5 and 20% in infants and toddlers. Oral liquid preparations appeared to be better accepted than tablets in preschoolers, but not for those under 3. Overall, these findings highlight the lack of suitable alternatives for the younger children, especially for formulations of antiepileptics, antithrombotic, and psycholeptic agents in the local context.

It is well established that treatment regime compliance is linked to the acceptability of a pharmaceutical formulation, and hence also to therapeutic outcomes. To that end, acceptability must be assessed during the development of all pharmaceutical products and especially for those intended for paediatric patients. Although acceptability is a multifaceted concept, poor sensory characteristics often contribute to poor patient acceptability. In particular, poor taste is often cited as a major reason for many patients, especially children, to refuse to take their medicine. It is thus important to understand and, as far as possible, optimise the sensory characteristics and, in particular, the taste/flavour/mouthfeel of the formulation throughout the development of the product. Sensory analysis has been widely practiced, providing objective data concerning the sensory aspects of food and cosmetic products. In this paper, we present proposals concerning how the well-established principles of sensory analysis can best be applied to pharmaceutical product development, allowing objective, scientifically valid, sensory data to be obtained safely. We briefly discuss methodologies that may be helpful in reducing the number of samples that may need to be assessed by human volunteers. However, it is only possible to be sure whether or not the sensory characteristics of a pharmaceutical product are non-aversive to potential users by undertaking sensory assessments in human volunteers. Testing is also required during formulation assessment and to ensure that the sensory characteristics remain acceptable throughout the product shelf life. We provide a risk assessment procedure to aid developers to define where studies are low risk, the results of a survey of European regulators on their views concerning such studies, and detailed guidance concerning the types of sensory studies that can be undertaken at each phase of product development, along with guidance about the practicalities of performing such sensory studies. We hope that this guidance will also lead to the development of internationally agreed standards between industry and regulators concerning how these aspects should be measured and assessed throughout the development process and when writing and evaluating regulatory submissions. Finally, we hope that the guidance herein will help formulators as they seek to develop better medicines for all patients and, in particular, paediatric patients.

Medicines for children often taste bitter, presenting a significant challenge to treatment compliance. However, most studies on paediatric drug development rely on adult volunteers for sensory research, and the level of expertise required from these assessors is unclear. This study aimed to address this gap by investigating perceived bitterness aversion to taste strips impregnated with different concentrations of quinine hydrochloride in 439 school-aged children. Expert (n=26) and naïve (n=65) young adult assessors evaluated quinine solutions as well as taste strips, for methodological bridging purposes. All assessors differentiated the aversiveness of the taste strips in a dose dependent manner. Younger children aged 4-8 years had difficulty discriminating higher bitter concentrations, whereas pre-adolescents 9-11 years and naive adults showed better discrimination at the top of the scale. Naive assessors showed similar bitter perception as children. However, the results were slightly different between strips and solution in adults. These findings highlight the key role that adult panels can play in paediatric formulation development. Taste strips show promise as a safe and pragmatic tool for sensory pharmaceutical evaluations, though further studies are warranted to establish the relationship between age and hedonic taste perception using compounds with diverse physicochemical and sensory qualities.