Background Most studies of the effectiveness of Thai drug labeling and documentation have focused on the readability and comprehension of drug contents without considering essential contributing factors (i.e., typographical design). This issue indicates a lack of knowledge about improving legibility through the use of appropriate typefaces and sizes for Thai drug packages and patient information leaflets. This study intended to review the Thai typefaces and sizes used in Thai drug labeling and documentation to discern their legibility and understand the problem of small typefaces. This study could lead to further studies and would be beneficial if applied to the development of appropriate legislation.
Methods To understand the status of the design of Thai drug labeling and documentation, the first part of this study qualitatively reviewed typographical issues related to the use of typefaces and determined the type sizes printed on several Thai drug packages and patient information leaflets. The typefaces and their letter sizes were observed via a digital microscope. Later, in the pilot study that followed, we comparatively examined the small font sizes in different typefaces through the participants’ reading of sample texts about drug content, and we measured their preferences by sorting reading text cards typed with different typefaces.
Results We found that two significant Thai typefaces have been used on drug labeling and drug documentation: conventional Thai text fonts and Roman-like Thai fonts. The typefaces are composed of varied small sizes. We found that the minimum type size is approximately 0.5 mm, which is diminutive. The average reading findings suggested that the conventional Thai text fonts facilitated the most participants who varied by age, more than the Roman-like Thai fonts. Moreover, we found that the average reading times between early adulthood participants and middle adulthood participants were dissimilar. The average reading times of the younger participants were fast, while the average reading times of the older participants were much slower.
Conclusions The present study examines how the use of proper typefaces and type sizes on Thai drug packages and patient information leaflets affects reading times and participants’ satisfaction. The study also reveals that few regulations have been developed and implemented, reflecting the fact that the designers and medicine manufacturers a lack sufficient knowledge and social responsibility, based on typographic principles. These findings suggest the need for further studies featuring a synergy of disciplines, e.g., pharmaceutics, psychology, design, social sciences, and law.