Diffusion Times of Spermicidal Compounds

Abstract

Summary and Conclusions

1. To estimate comparative contraceptive effectiveness of chemical compounds, under conditions approximating those of clinical contraception, each was incorporated in rice flour or tragacanth jelly. Time to immobilize all sperm in a column of human semen in contact with jelly was then observed. 2. The time of various compounds in commercial contraceptive mixtures, and of others, was compared in this way. both in concentrations used in commercial preparations and in concentrations 10 or more times as great. 3. XaCl had the shortest time observed, probably due in part to convection currents it creates in semen. Time of saturated sodium tartrate was also short. 4. Only a small proporation of compounds in concentrations used in contraceptive mixtures showed times shorter than the median of a series of commercial preparations. 5. Addition of compounds used in contraceptive mixtures to 10% X^aCl jellies did not result in times much shorter than that of XTaCl alone. From these results it is believed that in contraceptive mixtures greater spermicidal activity is to be expected from compounds of low molecular weight. Diffusion of such compounds from jelly into semen, which must necessarily precede spermicidal activity, will be more rapid than that of heavier compounds. Sodium chloride and sodium tartrate, which are nontoxic, appear desirable compounds for contraceptive mixtures.