Profiling key excipients in commercial oral antibiotic suspensions: a descriptive study of formulation trends and selected safety concerns

There is limited descriptive data on excipient use in oral antibiotic suspensions; this study provides a novel evaluation of commonly used excipients and their formulation rationale. A total of 41 suspensions representing nine antibiotic types were analyzed using patient information leaflets. The frequency of each excipient class was determined, and associations between suspending agents or preservatives and antibiotic classes were assessed. Selected qualitative safety concerns related to the listed excipients were identified. Amoxicillin/clavulanate was the most frequently represented antibiotic. Excipient details were available in 31 products, while 10 lacked disclosure. Xanthan gum, sodium benzoate, sucrose, titanium dioxide, and strawberry flavor were the most commonly used suspending agent, preservative, sweetener, colorant, and flavoring agent, respectively. Combinations of suspending agents, particularly xanthan gum with colloidal silicon dioxide, were common, whereas preservative combinations were rare. A significant association was observed between the type of suspending agent and the antibiotic class (p < 0.001), as well as between preservative type and antibiotic class (p = 0.001). The findings highlight formulation patterns, safety concerns, and transparency issues, providing novel insights to support safer pharmaceutical products and guide regulatory practice.