Background Manipulation of drug formulations (eg, crushing of tablets, opening of capsules) to achieve an appropriate dose is often necessary in the paediatric ward. Such manipulation has, however, been shown to result in inaccurate dosing (eg, not exceeding 76.5% of the intended dose for one aspirin formulation, in one study (Broadhurst, 2008)).

Purpose The purpose of this study was to investigate the dosing accuracy of two different, low dose aspirin tablets, commonly used in paediatric care, using a validated ultra high performance liquid chromatography (UHPLC) analysis.

Material and methods Aspirin tablets: Bayer Chewable (81 mg), Bayer Healthcare LLC, and dispersible aspirin (75 mg), Aspar Pharmaceuticals Ltd. Instrument: UHPLC system from Shimadzu Corp (Nexera, with Prominence diode array detector). Analytical column: ACE Excel 2 μm C18-AR, 2.1 × 100 mm (Advanced Chromatography Technologies Ltd). The analytical method was validated for linearity, precision and specificity. Dosing accuracy study: 6 tablets from each of the 2 formulations were each dissolved in 10 mL of water. After 3 min, samples (1 mL and 2 mL) were withdrawn. Dosing accuracy was recorded and compared between formulations and with previous findings.

Results Analytical method the analytical method was found to be stability indicating for aspirin. Dosing experiments: for dispersible aspirin (75 mg), 98.7% (80.0–117.3%) and 92.2% (76.0–113.3%) of the intended dose was found for the 1 mL and 2 mL samples, respectively. For Bayer Chewable (81 mg), 9.3% (6.2–22.2%) and 12.3% (4.9–28.4%) of the intended dose was found for the 1 mL and 2 mL samples, respectively.

Conclusion Using a validated UHPLC method, the dosing accuracy of dispersible aspirin (75 mg) was found to be better than previously published. The dosing accuracy of a second formulation (Bayer Chewable, 81 mg) was found to be poor. The study underlines the importance of considering formulations when manipulating tablets.

References and/or acknowledgements Broadhurst EC, Ford JL, Nunn AJ, et al. Dose uniformity of samples prepared from dispersible aspirin tablets for paediatric use. Eur J Hosp Pharm Sci2008;14:27–31.

No conflict of interest