Increasing research on makeup-related optics through the years have produced various products that are now on the market. Today, even the Internet web sites many cosmetic manufacturers noticeably contain information about new makeup finishes which adopt the optical effect, materials for producing the optical effect, and the mechanism of makeup optics. The main purpose of makeup is achieving a desirable finish. Since a good or bad makeup finish is ultimately judged by the human eye, makeup research cannot preclude a study of the optical effect. In the makeup products field, the word “optical” in most cases implies a focus on ultraviolet rays and visible rays. This paper focuses on visible rays in a study of the optical effect in makeup finish.
As we all know, the human visual faculty is extremely sophisticated. Unfortunately, there is no measuring instrument yet that can match the evaluation capacity of the human eye. Therefore, the evaluation of skin and makeup cosmetics naturally depends on sensory evaluation in a large number of cases. Aside from the devices for compound and complex evaluation, highly accurate measuring instruments have been developed and generally used for comparatively simple evaluations such as the color value (hue, brightness, chroma) and glossiness. The use of these optical measuring instruments has enabled researchers to gather data (which was difficult to obtain by sensory evaluation alone) in numerical form and to objectify this data. Needless to say, this has opened the way to big we introduce the measurement of skin optical characteristics and an evaluation of the advantages of makeup products using some of the new, recently developed makeup finishes as examples.

View full abstract

Olfactory sensation starts at the ciliary membrane of olfactory receptor cells located in the nasal cavity. The chemo-electrical transduction process is mediated by G-protein-coupled second messenger cascade, which produce a membrane current by direct gating of cationic channels (cAMP-gated channels). Opening of these cAMP-gated channels allows monovalent as well as divalent cations to enter the ciliary cytoplasm. This Ca influx serves two important functions. First, the Ca influx activates a Cl currents, which stabilizes the transduction current during fluctuations in extracellular cation concentration. Second, the Ca influx mediates adaptation by providing a negative feed back to cAMP-gated cation channels. Odorant masking is likely to be mediated by a suppressive effect of odorants on the cAMP-gated channel.

View full abstract

Odors can affect human consciousness and emotion. This paper reviews the effect of odor to human, especially physiological and psychological effects.

View full abstract

As the measurement of odor, it is generally classified three methods of which are sensory evaluation, physiological function analysis and physico-chemical analysis. General methods using in physico-chemical analysis are briefly discussed in this article including headspace analysis, GC-olfactometry and multidimensional GC.
GC-MS is generally used for the identification of volatile compounds. The development on identification system using the computer based on combination of MS spectra with retention indices improved the operation efficiency of the identification.
Headspace gas analysis can be applied to identify the volatiles of odor status without the process of extraction from products. GC-olfactometry getting also olfactory sense information at the same time is becoming more useful to identify characteristic compound in complex matrices, such as essential oils. Multidimensional GC can also be applied to the analysis of minor components presented at low concentration in a complex mixture.

View full abstract

We have studied why some cosmetics and toiletries containers made from resin unexpectedly undergo deformation, and developed the countermeasures against it. There were two causes for the deformation of containers. One is the decrease of air pressure inside the container through gas absorption by the contents. The other is the softening of the container affected by the contents. Through the study, we have 1) established the evaluation method for container deformation, 2) elucidated the findings that the ability to decrease the air pressure inside the containers through gas absorption (evacuation degree), and the ability to soften the container are different from material to material (softening degree), and that the ability of the contents to decrease the air pressure can be speculated from the abilities of each material involved.
Based on the findings obtained, it became possible to prepare the contents which have expected abilities for the air pressure decrease and the softening of the container. By performing the experiments using the contents and the containers with estimated abilities, we have analyzed the relationship between abilities of the contents and deformation of the containers, and developed the preventive countermeasures against the deformation of containers.

View full abstract

The long term UVA irradiation leads to photoaging characterized by features such as “sagging” and “thick wrinkle.” It will be considered that the structural change of the extracellular matrix in dermal is responsible for the features. To maintain the normal structure of dermis, the components such as collagen, elastin and glycosaminoglycans repeats the synthesis and the degradation. It will be considered that the unbalance between the synthesis and the degradation causes the structural changing in dermis. To inhibit or improve the change of the dermal matrix in the photoaging skin, we focused on controlling the activities of the matrix proteinases (collagenase and elastase) which increase after UVA irradiation. Then, we searched the effective ingredients having the inhibitory effect on each of collagenase and elastase activity. As a result, Eucalyptus extract inhibited both of the collagenase type I and the human fibroblast-derived collagenase activity. On the other hand, Elder extract showed the potent inhibition on the activity of the elastase (serineproteinase) from neutrophile permeated with the inflammation. It is suggested that Eucalyptus extract suppresses the degradation of type I collagen due to the inhibition on the collagenase type I (MMP-1) that is secreted by fibroblast after UVA irradiation. Moreover, Elder extract is effective as the ingredient which inhibits the neutrophile-derived elastase activity.

View full abstract

The in vivo evaluation of sunscreens against UVA has already been established since 1996 in Japan. This in vivo method gives the suffering to the healthy subjects because of using the dorsal skin of human in experiment. So we estimated a new in vitro evaluation of sunscreens against UVA instead of in vivo evaluation. After applying the sunscreen of 2mg/cm² on the transpore surgical tape, the tape put onto the 96-well microplate having 0.1ml of the mixture of 0.1mM-riboflavin solution, 8mM-methionine solution and 1.5mM-nitro blue tetrazolium (4:1:5) and irradiated with UVA at ranging from 350 to 380nm. By measuring the absorbance at 550nm at each 3min interval until 30min a regression formula between the absorbance and time gave an straight line. The in vitro PFA value was obtained from the formula of S_O/S_T shown as the slope of the line, S_O or S_T after treating either in the absence or in the presence of the sunscreen. In comparing the in vivo PFA values obtained from 11 sunscreens with the in vitro PFA values, both data were in high correlation. These data suggested that the developed method would be available instead of in vivo evaluation.

View full abstract

Active oxygen and free radicals have been implicated to cause various skin problems including wrincle, maculae and inflammation. In this study, we focused on squalene, and first investigated the effects of squalene peroxide, regard as being formed by the action of active oxygen and free radicals on the skin, in hairless mice. We observed various disorders including thickening of the epidermis and progressive cornification.
To investigate means of protection from oxidative disorders caused by active oxygen and free radicals, we focused next on plants which can grow even under situations where active oxygen and free radicals can easily be formed. We searched for natural materials of plant origin which can effectivity scavenge various active oxygen and free radicals. As a results, several plants showing high radical-scavenging activity were selected. Their radical-scavenging activities were further improved through limit the period of plant gathering, use of fresh leaves, selection of scavenging ability through breeding and combination of different plant extracts.
The experimental creams preparation containing certain combinations of extracts effectively prevented peroxidization of sebum by sunlight on human skin in situ. They also protected against squalene peroxidization induced by sunlight of titanium oxide commonly used in foundations.

View full abstract