Media fill tests: application for aseptic preparation at hospital pharmacy

Media fill test is a process simulation testing which is carried out in the same manner as that of normal production except that an appropriate microbiological growth medium is used in place of the drug.

Process simulation is a basic requirement for validation of aseptic compounding in accordance to worldwide regulations i.e. Eudralex-volume 4 Good manufacturing practices guidelines- annex 1 Manufacture of sterile medicinal product for industry and specific guidelines for hospital pharmacy such as PIC/S guide to good practice for the preparation of medicinal products in healthcare establishments, US pharmacopeial convention USP <797> Pharmaceutical compounding –sterile preparation, French good manufacturing practices for hospital and community pharmacies (Bonnes Pratiques de Préparation), Swissmedic Good manufacturing practice for small quantity preparation (Bonnes Pratiques de Fabrication des médicaments en petite quantité).

At hospitals, most of the time the maximum workload is very low (<300 units) in comparison to pharmaceutical industry and it is quite usual to produce Taylor-made preparations instead of standardized batch production. Media fill tests should be then adapted to the hospital production taking into consideration the maximum workload and the different methods used in the process i.e different raw materials (liquid powder), different methods of transfers (manual, robotized) and the different final contents (syringes, bags, diffusors).

Before process validation by media fill test, it is mandatory to validate operators who will conduct further the process validation.

Standardized method for operator’s validation of aseptic process has been published by NHS (universal operator broth transfer validation) and by USP <797>. Nevertheless, due to the low number of units produced, it is exceptional to found any contamination of units in the controlled areas such as sterile isolators or BSC’s. That is why we developed specific media fill tests challenged with microorganisms [1]. This optimized method coupled with visual observation using USP <797> observational grid allowed us to detect aseptic errors of handling. This method was included in the routine assessment of our operators and contributed to improve the quality of the education and validation of operators at hospital pharmacy.