The Influence of Increasing Concentrations of AMPD on the Efficacy of Its Penetration into a Model Skin Sebum Layer

Alcoholamines are widely used as auxiliary substances in various topical preparations. Their impact on the components of skin sebum allows them to be used in preparations that cleanse the skin of sebum in hair follicles. We measured the effects of various concentrations of aqueous solutions of AMPD (2-amino-2-methyl-1,3-propanediol) on model skin sebum. The volume of reacted sebum was calculated using two methods: optical assessment of the interaction of alcoholamines with the components of model skin sebum and determination of the reacted volume of model skin sebum based on the measurements of changes in the pH of the AMPD solutions. Both methods showed that the most favorable AMPD concentration for model sebum penetration was approximately 1-2%. Lower values of alcoholamine caused premature exhaustion from the solution. Excessively high concentrations resulted in the formation of a dense layer of products hindering effective skin cleansing.

Green chemical mechanical polishing of sapphire wafers using a novel slurry

Toxic and corrosive solutions are widely used in the preparation of abrasives and chemical mechanical polishing (CMP) of sapphire wafers, resulting in potential environmental pollution. Developing a novel green CMP technique to achieve light-emitting diode sapphire wafers is a significant challenge. In this study, a novel green CMP slurry, consisting of silica, sorbitol, aminomethyl propanol, and deionized water was developed for sapphire wafers. After CMP, the sapphire wafers were cleaned with deionized water and dried with compressed air, which is a green process. After CMP, the surface roughness Ra of the sapphire wafer surface with an area of 5 × 5 μm2 was 0.098 nm, which is the lowest surface roughness reported to date for sapphire wafers. Tetrahydroxy-coordinated Al(OH)4- ions were produced in the alkaline CMP slurry, and chelation occurred between sorbitol and these ions. The proposed green CMP has potential applications in the semiconductor and microelectronics industries.

Safety Assessment of Tromethamine, Aminomethyl Propanediol, and Aminoethyl Propanediol as Used in Cosmetics

The Cosmetic Ingredient Review (CIR) Expert Panel (Panel) reviewed the safety of tromethamine, aminomethyl propanediol, and aminoethyl propanediolas used in cosmetics. All 3 ingredients are reported to function in cosmetics as pH adjusters, and tromethamine and aminomethyl propanediol are also reported to function as fragrance ingredients. The Panel reviewed relevant animal and human data related to these ingredients, along with a previous safety assessment of aminomethyl propanediol. The Panel concluded that tromethamine, aminomethyl propanediol, and aminoethyl propanediol are safe in cosmetics in the practices of use and concentration as given in this safety assessment.