Cosmetics Technology Lecture 7: Haircare Tech (I) PDF

Cosmetics Technology [ELCT 1021] Lecture 7: Haircare Tech (I) BY: DR. SHAHIR AZIZ P H A R M A C E U T I C A L T E C H N O L O G Y D E PA R T M E N T F A C U LT Y O F P H A R M A C Y & B I O T E C H N O L O G Y WINTER 2024 - CONTACT: [email protected]...

Cosmetics Technology [ELCT 1021] Lecture 7: Haircare Tech (I) BY: DR. SHAHIR AZIZ P H A R M A C E U T I C A L T E C H N O L O G Y D E PA R T M E N T F A C U LT Y O F P H A R M A C Y & B I O T E C H N O L O G Y WINTER 2024 - CONTACT: [email protected] DR. SHAHIR AZIZ – COSMETICS TECHNOLOGY (ELCT1021) – WINTER 2024 1 Lecture Outline  The Hair structure and health  Hair Fiber Structure  Hair Physical properties  Tensile Properties  Stress Relaxation Properties  Sorption & Swelling Properties  Bending & Torsional Properties  Hair Surface properties  Wettability  Luster & Shine  Friction & electrostatic charge generation  Haircare product categories DR. SHAHIR AZIZ – COSMETICS TECHNOLOGY (ELCT1021) – WINTER 2024 2 The Hair structure and health Hair fiber structure A) Hair shaft; is the visible part of the hair B) Hair root; extends down into the deeper layers of the skin reaching the SC layer. It is surrounded by the Hair follicle (i.e.: a sheath of skin and connective tissue), which is also connected to a sebaceous gland. Arrector pili is a small muscle attached to the follicle that makes the hair shaft stand straight by pulling the root. Also connected to very sensitive nerves that can detect hair shaft movement. C) Hair bulb; is the hair root base enclosing the hair papilla that supplies the root with blood and lymph vessels. (i.e., new hair cells generation site, InformedHealth.org [Internet]. Cologne, Germany: Institute for Quality and Efficiency in Health Care (IQWiG); 2006-. nourishment and endocrine control). What is the structure of hair and how does it grow? 2019 Aug 29. Available from: https://www.ncbi.nlm.nih.gov/books/NBK546248/ DR. SHAHIR AZIZ – COSMETICS TECHNOLOGY (ELCT1021) – WINTER 2024 3 The Hair structure and health Hair fiber structure Hair shaft; is the visible part of the hair with average thickness of 50-100 microns in an adult. DR. SHAHIR AZIZ – COSMETICS TECHNOLOGY (ELCT1021) – WINTER 2024 4 The Hair structure and health Hair fiber structure Hair shaft – Hierarchy / Composition  The innermost section of the hair is the Medulla. The middle section is known as the Cortex.  The Cuticle is the outer layer of the hair shaft and forms a protective membrane around.  The cortex consists of α-Keratin protein fibers (65–95 wt.%) that are closely bound together. This is the most important part of the hair and contains the natural pigment (i.e. Melanin) which gives the hair its color and texture.  The cuticle has 4 to 8 overlaying cells that are cemented to the cortex with the Cell Membrane Complex (CMC).  Closed cuticles will give more light reflection and shine. DR. SHAHIR AZIZ – COSMETICS TECHNOLOGY (ELCT1021) – WINTER 2024 5 The Hair structure and health Hair fiber structure Hair shaft – Hierarchy / Composition  The inner section “Cortex” is composed of cortical cells that are spindle shaped lie parallel along the fiber axis and 1–6 μm thick. These cortical cells are composed of subcomponents called Macrofibrils. The macrofibrils exhibit a diameter of 0.1–0.4 μm.  At the nanometer scale, they are composed of intermediate filaments (IF) embedded in a matrix with high-sulfide content. One IF has a diameter of ~7.5 nm and is formed by eight Protofilaments (α-helix chains).  CMC is the adhesive and hydrating layers (Beta & Delta) composed of Fatty acids, Cholesterol & Ceramides. DR. SHAHIR AZIZ – COSMETICS TECHNOLOGY (ELCT1021) – WINTER 2024 6 The Hair structure and health Hair fiber structure Hair shaft – Hierarchy / Composition  The Cuticle, is the hard outermost layer formed by flat keratinized cells in a scale-like formation facing downwards.  The epicuticle (i.e.: A-layer): is a lipo-protein membrane that is estimated to be 10–14 nm thick with a high cysteine content. Attached to its surface; fatty acids (Stearic and Palmitic acids and the branched chain, anteiso-18- methyleicosanoic acid (18-MEA)).  The exocuticle with a high cysteine content and a highly variable thickness ranging from 50 to 300 nm.  The endocuticle with a low cysteine content and a variable thickness giving weak mechanical strength and it is highly swellable. DR. SHAHIR AZIZ – COSMETICS TECHNOLOGY (ELCT1021) – WINTER 2024 7 The Hair structure and health Hair fiber Physical Properties 1) Tensile Properties  Hair exhibits a high tensile strength, 150-270MPa, which is significantly dependent on strain rate, humidity temperature and the biotransformation of α-helix to β-sheet keratin. DR. SHAHIR AZIZ – COSMETICS TECHNOLOGY (ELCT1021) – WINTER 2024 8 The Hair structure and health Hair fiber Physical Properties 2) Stress Relaxation Properties  When a hair fiber is extended by stress and kept at this extension length and then decreases the stress over a period (function of time).  Human hair is Viscoelastic, and that when quickly extended to a moderate degree (0.5-6.5%) and held, the force generated will fall to half its original value in about 15 h. This was due to the structural rearrangements (deformation of peptide bonds which is rich in CO- , NH- and SH- groups) while under extension. DR. SHAHIR AZIZ – COSMETICS TECHNOLOGY (ELCT1021) – WINTER 2024 9 The Hair structure and health Hair fiber Physical Properties 3) Sorption & Swelling Properties From; Cruz, C.F., Ribeiro, A., Martins, M. and Cavaco-Paulo, A. (2017), Effect of a peptide in cosmetic formulations for hair volume control. Int J Cosmet Sci, 39: 600-609. https://doi.org/10.1111/ics.12415 Change in Mass (%) Relative Humidity (RH%)  Both types of hair have similar water sorption (change in hair mass %); however, a variable hair volume change occurred.  Test Conclusion: The hair surface and the endocuticle of the Caucasian hair have lower hardness and elastic modulus than the “Asian hair”. This led to an increased extension, higher cuticle scales lift and higher hair tress volume. DR. SHAHIR AZIZ – COSMETICS TECHNOLOGY (ELCT1021) – WINTER 2024 10 The Hair structure and health Hair fiber Physical Properties 4) Bending & Torsional Properties  The behavior of human hair under torsional and bending Torsional pendulum technique stresses and strains is an important contributing factor for the formation and maintenance of a hair style. A very important aspect to determine if products will be efficacious when used by the consumer.  Using the torsional pendulum technique is measure of rigidity and oscillation behavior. 3-Point Cantilever  Using the 3-points Cantilever technique for the evaluation of technique the mechanical properties, such as toughness, elastic modulus, stiffness, flexibility, and plasticity. DR. SHAHIR AZIZ – COSMETICS TECHNOLOGY (ELCT1021) – WINTER 2024 11 The Hair structure and health Hair fiber Surface Properties 1) Wettability  The cuticle hydrophobic protective layer has low surface energy that prevents uniform wetting by polar matter as Water.  When washing hair to remove hydrophobic Water contact angle (WCA) is the commonly used test in laboratories to determine the wettability of materials, if WCA is contamination or even frequent grooming, smaller that 90°, the material is hydrophilic, if WCA is larger than or equal to 90°, the material is hydrophobic reducing the intactness of the hydrophobic layer, might as well disrupt the natural wettability profile of the hair. DR. SHAHIR AZIZ – COSMETICS TECHNOLOGY (ELCT1021) – WINTER 2024 12 The Hair structure and health Hair fiber Surface Properties 2) Luster & Shine  A very significant property that is measured by the light reflected of the fiber surface using a Goniophotometer technique.  It is based on the principle of a photometer with a revolving arm that is fitted with a circular mirror. Light is continuously fed to this mirror through different angles (as the arm rotates) which provides information about the luminous flux, intensity distribution, and efficiency of the source. DR. SHAHIR AZIZ – COSMETICS TECHNOLOGY (ELCT1021) – WINTER 2024 13 The Hair structure and health Hair fiber Surface Properties 3) Friction & electrostatic charge generation INSTRONO® sled friction: To test the coefficient of friction, a weighted sled is  Frictional interactions due to grooming or haircare pulled across the surface of a treated hair bundle. products application depends on the nature of the cuticle the force required to move the sled against the hair is cell orientation direction and its lipo-protein content. measured.  Also, the level of friction is directly proportional to the tendency to develop electrostatic charges that lead to difficulty in hair style management (i.e.; Fly-away)  Moisture and humidity content & its distribution along the hair fiber has a striking effect on the fly-away behavior due to the enhanced conductivity of the electric charge. DR. SHAHIR AZIZ – COSMETICS TECHNOLOGY (ELCT1021) – WINTER 2024 14 Haircare Products DR. SHAHIR AZIZ – COSMETICS TECHNOLOGY (ELCT1021) – SPRING 2024 15 Haircare products Shampoo  The #1 haircare product developed to replace soap for cleansing the scalp and hair fibers by removing excess sebum, dandruff, environmental dust, and residues from other haircare products. Most dirt, including sebum, is water- insoluble and cannot be effectively removed by water alone. Regular Daily-use Conditioning Clarifying 2-in-1 Dry shampoo DR. SHAHIR AZIZ – COSMETICS TECHNOLOGY (ELCT1021) – SPRING 2024 16 Haircare products Although there are 6 main categories of shampoo products, Regular Daily-use Conditioning Clarifying 2-in-1 Dry shampoo We are crowded by hundreds of types From the Market perspective. DR. SHAHIR AZIZ – COSMETICS TECHNOLOGY (ELCT1021) – SPRING 2024 17  References: Harry's Cosmeticology, 8th Edition Thank you By MARTIN M. RIEGER Handbook of Cosmetic Science and Technology 3rd Edition by André O. Barel, Marc Paye, Howard I. Maibach DR. SHAHIR AZIZ – COSMETICS TECHNOLOGY (ELCT1021) – WINTER 2024 18