Differences between generic and Brand Specific Approved (BSA) anticoccidials.

Different maduramicin 1%-premixes were compared for evaluation of quality. Anticoccidial premixes consist of two elements: active compound and carrier. Eleven generic premixes originating from different countries were compared with Cygro®, the only EU BSA-approved maduramicin. Maduramicin concentrations were analysed and compared. Only Cygro® contained the claimed concentration. One generic had lower concentration than claimed (0.75%); all the other generics had at least 10% more active than claimed. Underdosing anticoccidials can cause poor control of coccidiosis, higher oocyst output and has been suggested to induce resistance faster. Overdosing maduramicin can cause target animal safety problems. Premix quality was evaluated, using laser diffraction equipment, for parameters that impact homogeneity and thus imply a risk for underor overdosing. Next to Cygro®, only three out of eleven generics had good results for premix features. Combined with active evaluation, just one generic would have passed release specifications of Cygro®. Another batch of this generic had excessive maduramicin content and poor particle strength. As a conclusion, these results confirm the need for high requirements for anticoccidial premix registrations such as BSA in the EU. Generic premixes might cause significant problems during (poor parasitological control, toxicity) and after use (higher infection pressure, faster resistance). __________________________________________________________________________________