Application of the isotope technique in pharmacodynamic analysis of penetration of drugs into parasites.

Penetration of piperazine adipate into Ascaris lumbricoides var. suum L. was studied by scintigraphy andautoradiography. The results indicate that anthelminthic drugs, including piperazine, penetrate into the parasite mainly through the mouth or other natural orifices, and only slightly through the cuticle, and that the amount of piperazine that penetrates depende on its concentration in the solution.