Role and Safety of Excipients in Syrups (Review)

INTRODUCTION. Syrups are an important dosage form used in medical practice, particularly in paediatrics. As of January 2024, there are 212 medicinal products formulated as syrups approved in the Russian Federation. The effi­cacy, safety, and quality of syrups are determined by their composition, including excipients.

AIM. This study aimed to analyse and systematise data on the role and safety of excipients in syrups included in the Russian State Register of Medicines.

DISCUSSION. This article reviews the major groups of excipients present in syrups, including sweeteners, preservatives, solvents, thickeners, pH modifiers, buffering agents, antioxidants, and colourants. The most prevalent group of excipients is sweeteners, including sucrose (66.51%), sorbitol (29.25%), and sodium saccharin (10.85%). Sucrose contributes to tooth decay and is contraindicated in patients with diabetes and obesity. Sorbitol may cause gastrointestinal disorders. Data on the long-term safety of artificial sweeteners are contradictory. Therefore, sweeteners should be selected rationally. The most widely used preservatives are parabens, including methylparaben (31.60%) and propylparaben (20.28%). Propyl­paraben exhibits potential oestrogenic activity, which makes methylparaben the para­ben of choice. Solvents and co-solvents include water, glycerol (25.94%), ethanol (24.53%), and propylene glycol (20.75%). Ethanol and propylene glycol can cause severe central nervous system disorders. The most commonly used thickener is hydroxyethyl cellulose (5.19%). Cellulose derivatives are considered safe but may have a laxative effect if consumed in excess. The most popular colourant is Sunset Yellow (7.54%). The lack of data on the safety of many colourants emphasises the need for their rational selection.

CONCLUSIONS. By analysing summaries of product characteristics and patient information leaflets for syrups available in the Russian State Register of Medicines, the authors have systematised data on the role, safety, and acceptable daily intake of excipients in used syrups, classified these excipients, and calculated the frequency of their use. The findings suggest that the current approaches to selecting excipients for syrups should be revised to minimise potential risks and to enhance the safety of medicinal products.

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