Background Preparation of capsules is common in hospital pharmacy when an adapted dosage is not available on the market. According to the Good Manufacturing Practices, validation of processes and operators are essential to ensure the quality of preparations.

Purpose To evaluate and validate the operator's accuracy during the manual process of capsules preparation. Materials and Methods Operators had to manually prepare, without using mannitol carmine, 3 batches of 100 capsules. Each 250 mg capsule (size 2) contained 6 mg of phenylephrine used as a tracer. Ten capsules in critical points of the capsule filler (2 in every corner and 2 in the centre) were analysed according to the European Pharmacopeia (uniformity of mass and content). Phenylephrine was determined by a validated capillary electrophoresis-UV method. Results were analysed considering the operator's experience based on the years of experience and the frequency of execution (low, medium and high).

Results Forty-two batches were produced by 14 operators (11 technicians and 3 pharmacists). Mass uniformity: all batches were conform. The mean mass (±SD) was 247.5 mg (±3.8). The mean mass obtained by the operators with low (n=6), medium (n=4) and high (n=4) experience were 244.6 (±2.4), 247.9 (±2.3) and 251.6 mg (±2.7), respectively (r²=0.60). Content uniformity: 6 batches (14%) were not conform. 9/14 operators (64%) passed the test for 3/3 batches, 4/14 (29%) for 2/3, and 1/14 (7%) for 1/3. The mean content for low, medium and high experience was 95.6 (±3.0), 96.9 (±2.1) and 97.0% (±2.5) of the target concentration, respectively (r²=0.06).

Conclusions All operators displayed adequate skills to uniformly fill capsules, with a trend to a better performance by experienced operators. However, insufficient homogenisation of the mixture was observed, independently of the experience. Further studies are needed to evaluate different systems from producing consistent mixtures.