Background The Quantos® powder dosing system (Mettler Toledo, Germany) offers the filling of small amounts of powders and liquids into different containers. Although it is already used for handling of hazardous substances and/or preclinical drug development, very few experience exist for the routine manufacturing of capsules in a hospital pharmacy.

Purpose Evaluation of the accuracy and practicability of Quantos® as compared to the manual capsule filling (MAN) method in a hospital pharmacy. Methods Different batches of hydrochlorothiazide and spironolactone capsules, at three dosage levels each, were produced using standard triturations. Quantification of the active ingredients was done by UV/Vis-spectroscopy using a validated method and evaluation according to the standard examinations for capsules of the European Pharmacopoeia (Ph. Eur. 2.9.5/6 and 40) was performed. The time required for each production step was measured.

Results All batches passed the examinations for uniformity of mass and content (in relation to arithmetic mean) with a lower standard deviation for Quantos® vs. MAN (1,91–3,35% vs. 3,20–7,84%). Almost all batches contained about 90% of the declared dosage, although the content of the used triturations was almost 100%. As a consequence, Ph. Eur. 2.9.40, which additionally refers to the desired value, Quantos® batches passed more often than MAN. In comparison to the manual capsule filling, the Quantos® system was slower.

Conclusion With both methods, capsules that are in accordance with the requirements of the Ph. Eur., can be produced. Although the Quantos® system is able to fill the capsules more precisely and allows a GMP-conform documentation, the handling process for day-to-day capsule manufacturing seems to be improvable. The recovery rate of about 90% might be due to the incomplete emptying of the capsules before quantification. This finding also has major implications for the common practice of emptying capsules on the wards and needs further investigation. Acknowledgements We thank Mettler Toledo permitting the project by lending a Quantos® powder dosing system.