Hi

In the case of a mixture of 8 antibiotics, it seems impossible. What you observe is the result of the interaction of individual substances. These interactions can take place at many levels, ranging from purely physicochemical to that related to mechanism and mode of action.

But panta rhei. ... :) .... maybe if you designed, for example, the composition of the test mixture (the concentration of individual antibiotics, for example, mixture one 1;1;1;1;1;1;1;10 next 1;1;1;1;1;1;10;1, etc ) using DOE (design of experiments) methods and, for example, combine it with a suitable soft for DOE or AI (artificial intelligence) ..... you could get really interesting results. First of all, you could create interesting pharmacometrics analysis tool. Maybe it's worth a try? Try to start working with someone who deals with pharmacometrics. Common sense of this research will be rather an analysis of possible interactions and it will be more interesting than the EC50 assessment. Such a problem/methodology is very interesting from a tox point of view. For example, current ADI values are calculated for single substances, not for a mixture of different .....

I'm not sure it helps but the question was very inspiring for me :)

Best regards

Tomasz

Check https://link.springer.com/article/10.1007/s40710-014-0009-7

Also check https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4206747/

Thank you Tomasz Grabowski . It would be an exciting approach. Unfortunately, it falls outside my general project. But really appreciated.

Thank you Chinaza Godswill Awuchi for the references. Those approaches are closer to my idea of assessing the toxicity of the mixture.

I think so

Try to separate the compounds and test each one alone, or the determined LD50 is LD50 of the mixture.