234 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS 80 40 drain time, sec. Na Lauroyl Sarcosinate with Oil I Na Lauroyl - , Sarcosinate ••,,,__ Cocoam•,•1•'-'--•t-•BetainePropyl -- with O, Cocoam_ido Lauramide Lauramide Prøpyl •.••111 • DEA with Oil D.......•.... • • ............ • •ll-"-' ....... 0 Na Lauryl Ether (3) Surfate 1.0% active 1.0% active Test Surfactant 0 Figure 13. Lather drainage time for surfactant mixtures--sodium laureth (3) sulfate. 80 Na Lauroyl I Na Lauroyl Sarcosinate • Sarcosinate with Oil --..... ..... DEA•/ Lauramide • / #' -/ DEA with -* / / / o," '--•/ / / / / // / Cocoam,do / / / / ../ ..... ••...• • • CocoamOII • ,,•- with 60 drain time, 20 0 0 Na C14-16 Olefin Sulfonate 1.0% active 1.0% active Test Surfactant 0 Figure 14. Lather drainage time for surfactant mixtures--sodium Cl4_16 olefin sulfonate.

LATHERING POTENTIAL OF SURFACTANTS 235 This dilution was chosen to provide active surfactant concentrations somewhere near the actual use concentration (3). Data for a variety of consumer products are presented in Table I. These data parallel the general lathering ability of the principal surfactant listed on the ingredient section of the package label. Our work on consumer products was intended primarily to evaluate the test method as a comparative tool for finished formulations. It also enabled us, however, to determine the effect of formulation post-additives on the latherability of these finished products. In doing this, we added 1.5% active sodium lauroyl sarcosinate to three of the consumer shampoo products in an attempt to produce thicker lathers in the presence of the oily soil loading. Lather drainage trials were conducted on 200 ml of a 1:10 dilution of these treated shampoos. The results (Table II) show that even this minor amount of added sodium lauroyl sarcosinate significantly increased the lathering drainage times in the presence of the oily soil loading. This would suggest a possible approach for product improvement. CONCLUSION A simple and rapid method for the empirical comparison of the lathering ability of surfactant systems and formulations has been developed. Wide variations in the ability Table 1 Lather data for consumer shampoo formulations. BRAND Lather Drainage, sec.-- Principal and Type 10% pH No Oil w/Oil Surfactant BRAND A Normal 6.55 53 51 NaLS Oily 6.70 47 52 NaLS BRAND B Normal 6.20 50 49 NH,•LS Oily 6.60 50 40 NH,•LS BRAND C Normal 6.85 51 24 TEALS Oily 6.65 47 22 TEALS BRAND D Normal 6.15 46 45 NaLS Oily 5.40 41 5 Na Laureth Sulfate BRAND E 7.65 47 25 TEALS