Shampoo Subject

The sulfate group is attached to the lauryl and laureth surfactants through an ester linkage. These detergents are therefore subject to hydrolysis at extreme values of pH. As a result, shampoos containing these surfactants are generally formulated with a pH between 5 and 9. 

An examination of the composition and physical state of sebum suggests that several cleaning mechanisms can operate during its removal from hair. Since sebum is completely molten at body temperature [122], it can be effectively removed by the roll-back mechanism. Also, the presence of approximately 25% free fatty acids in sebum indicates, as discussed in Section IV.C.3, that it is subject to removal by emulsification and mesophase formation. Finally, because the concentration of detergents during shampooing is well above their critical micelle concentrations, sebum can also be cleaned from hair by solubilization. 

Utility of arginine as a compensation factor for confounding factors was investigated by comparison with RSD values. The influence of a shampoo and a permanent wave used in daily life was also examined in respect with each hair, which was cut into pieces at intervals of 1 cm collected from six healthy subjects. 

Patients with psoriasis (57) and healthy volunteers (53) with no reported exposures to coal tar shampoos or ointments, self-applied either an ointment or a gel-based coal tar product, or both, to the entire body surface at least once a day, followed by UV-B treatment (Santella et al. 1994). The estimated exposure was 20-100 g/tar/day. Twenty-four-hour urine samples were collected from all subjects. Urinary 1-hydroxypyrene was analyzed by HPLC. Urinary PAH metabolites measured by the PAH-ELISA were elevated in patients (mean 730 1,370 mmol) as compared to untreated volunteers (110 90 mmol equivalents of B[a]P/mol creatinine). Urinary levels of 1-hydroxypyrene were also elevated in patients (mean 547 928 mmol/mol creatinine) compared with untreated volunteers (mean 0.14 0.17 mmol). 

Several studies have shown significant differences in the composition of oily versus dry hair. Perhaps the most comprehensive study in this regard was by Koch et al. [152], who examined hair surface lipid from 20 dry- and oily-haired subjects, three days after shampooing, and found the following correlations with increasing hair oiliness ... 

Perceptions in Cleaning Hair and the Subjective Testing of Shampoos 221... 

Questions regarding the removal of sebaceous soil and other soils from hair are fundamental to the action of shampoos however, another fundamental question is Which is more important to the sale of shampoos—the actual abilities of different shampoos to remove soil from hair or factors relevant to the perception of cleaning such as lather, viscosity, and fragrance Laboratory or in vitro tests are critical to provide an understanding of shampoo behavior. However, subjective tests are ultimately involved to evaluate the consumer s response to the total product. The next section describes some of the more common subjective tests used in shampoo development and raises some important questions. 

For this discussion, discemibility is considered as the objective (not necessarily numerical) ability of the users of a product to isolate and to discriminate between effects on hair without being influenced by related stimuli such as fragrance, lather, and viscosity. Perception, on the other hand, is the subjective response to a hair property, and this response is influenced by all related stimuli including the hair property itself, advertising and label copy, and all relevant shampoo properties. 

Some of this author s conclusions relevant to different types of shampoo (product) tests are described next. In general, objective discernibility of a hair effect becomes progressively less important as one proceeds from laboratory to sales tests. This is because subjective perceptions involving psychologically related stimuli become more important as one moves from the laboratory (where experimental control isolates discernibility from perception) to sales testing. 

Once the five subjects were admitted to the study, a 14-day pretrial period was observed. During this time, subjects avoided the use of medicated soaps, lotions, shampoos, deodorants, chlorinated water baths, and ultraviolet light tanning beds, as well as skin contact with solvents, acids, and bases. This regimen permitted stabilization of the normal microbial flora populations on the skin. 

A 7-day pretest period is adequate to assure elimination of any antimicrobial action residual from use of medicated personal hygiene products. During this period, subjects should be instructed to avoid using medicated hand soaps, hand wipes, hand gels, lotions, deodorants, and shampoos, as well as skin contact with solvents, detergents, acids, and bases or any other products known to affect the normal microbial populations of the skin. Each subject participant should be sup-... 

Captan (Dangard, Vancide 89) is used as a fungicide on fruits and vegetables. Used as an antiseborrhoeic agent in a shampoo, it caused one case of photoallergic contact dermatitis (Epstein 1968). In a human Draize test 1 % Captan sensitized 4.4% of the subjects (Marzulli and Maibach 1973). 

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