Background and importance Codeine mixed with calcium salts filled into capsules is used to treat chronic diarrhoea in transplant, oncological and geriatric patients, and in patients with irritable bowel disease. At least 11 500 hard capsules are regularly prepared from a manually blended powder mixture in the hospital pharmacy per month. Turbula 2F2 blender has been introduced into the hospital pharmacy to optimise the mixing process.

Aim and objectives To establish optimal blending time and speed for mixing of codeine with the Turbula 2F2 blender and to verify homogeneity by determining the amount of codeine in the samples, a validated spectrophotometric analytical method was used.

Material and methods The total amount of prepared mixture was 245.7 g containing 4.5 g of codeine phosphate (1.83%). The optimal rotation speed of Turbula was established as 49 rounds per min (RPM) based on visual analysis with colourant instead of codeine.

A 2 litre polyethylene container for homogenisation was used. Calcium carbonate was premixed with colloidal silica, and codeine and tricalcium phosphate added. Five samples for analysis were taken from different places in the container after 5, 10, 15 and 20 min of mixing. Expression of relative standard deviation (RSD) was used to evaluate the homogeneity of codeine in the mixture.

Results The results are summarised in table 1.

Conclusion and relevance Based on the results, the optimal time of 10 min was estimated for mixing of the codeine mixture at 49 RPM. The use of the Turbula 2F2 mixer was beneficial in reducing pharmacy staff exposure to powder particles of hazardous drugs and in reducing the risk of cross contamination in the laboratory.

References and/or acknowledgements No conflict of interest.