[Evaluation in vivo of the hydaluronidase activity of a substance by means of the cutaneous clearance of a radioactive tracer. Determination of the hydaluronidase activity in combination with equal parts of 2-(beta-chloroethyl)-2,3-dihydro-4-hydroxy-(benzo-1,3-oxazine) and 1,4-diphenyl-3,5-dihydroxypyrazolidine].