Quantitative Relationship between the Viscosity of Pediatric Syrups Containing Ambroxol Hydrochloride and the Adhesive Remaining Amount in the Metering Glass

Abstract

Background: In Japan, prescribing syrup formulations is the mainstay of drug therapy for pediatrics. Pharmacists measure the prescribed amount of these solution syrups using an easy-to-use metering glass. However, when measuring high-viscosity syrup in portions, some of the syrup may remain on the inner wall of the metering glass, significantly reducing the accuracy of the measured volume. Objective: The purpose of this study was to improve dispensing accuracy by identifying the syrups with the lowest amount of residue in the metering glass among the original and four generic syrups for pediatrics containing ambroxol hydrochloride. Methods: Three metering glasses made of different materials (glass, polypropylene, and polymethylpentene) were used and residual adhesion rate was calculated from the amount of syrup remaining on the metering glass. Results: In all metering glasses used for the measurements, the original syrup containing ambroxol hydrochloride had a higher viscosity and a significantly higher residual adhesion rate than its generic products. Conclusion: It was suggested that selecting generic drugs with low residual adhesion rates for syrups containing ambroxol hydrochloride improves the accuracy of dispensing syrups.