[Erythromycin determination in organ tissues (author's transl)]

The recovery rates of erythromycin after in vitro and in vivo administration were studied comparatively in liver, lung, and kidney. Using buffer standards the recovery rate in homogenates of in vitro administered erythromycin decreased with increasing protein concentration. At constant protein concentration the erythromycin administered recovered correlated linearly. Mincing the tissues with scissors was not found to be adequate, even when followed by a diffusion period of up to 24 hours. Similarly, shock freezing resulted in lower values. Even and optimal breaking down of tissues was found after homogenisation or ultrasonics. The recovery rates were not raised by treating the tissue with trypsin. There was no evidence of enzymatical erythromycin degradation in liver homogenates under the assay conditions.