The spermicidal powers of chemical contraceptives VII. Approved tests

Extract

1. All tests of spermicidal power are done with human semen at 37° C.

2. The total spermicidal power of pure substances and commercial products is measured by a test which is not intended to represent natural conditions very closely, but which gives consistently reliable results. The activity of the sperms is determined at 5 and at 30 min.

3. A commercial product of high total spermicidal power may be useless on account of the slow rate of diffusion of the spermicide out of the vehicle. A special test measures the rate of diffusion. This test is designed to represent natural conditions as well as is possible in the laboratory. The test is made as stringent as possible by avoiding mechanical mixture of the product with the semen. The activity of the sperms is determined at 2, 5, 15, 30, 60, 120, and 180 min.

4. The rate of disintegration and acidity or alkalinity of commercial products is measured.

5. The pathological test consists in inserting one-half the prescribed dose of a commercial product into the vagina of a bitch daily (except Sundays) for a fortnight, and then sectioning the vagina and examining microscopically.

6. A method is described whereby the pH of human semen may be determined colorimetrically rather accurately.

7. The average ejaculate of the human semen we have studied, from 13 donors, measures 3·9 c.c, contains 461 million sperms, and requires 3·1 c.c. of N/100 HCl to neutralize it.