Developing Skin Cleansing Compositions with Care and Beauty Benefits:

Transcription

1 Developing Skin Cleansing Compositions with Care and Beauty Benefits: Challenges and Opportunities IMWSCC, February 18, 2016 Martin Vethamuthu, PhD Principal Scientist, Care Specialities 1 1

2 Outline Background Key Elements of SKIN Cleansing science Cleanser Base : Mildness optimization Foam Design- Sensory vs Moisturization Post Wash Hydration: Beauty Benefits Challenges & Opportunities 2

3 Applications spectrum : Rinse-off cosmetics Suspension of acid, scrubs / exfoliants Suspension of emulsion / oil droplets + beauty Ingr. Mild bars, foam Wear rate ph 10 ph-4.6 ph-5.6 ph-5.7 ph 6.8 ph 5.5 ph 6.5 ph-4.7 ph-5.5 ph-6.8 Base mildness, tear free ph 6.8 ph 6.6 ph 5.5 Fragrance impact, Isotropic, visual impact, foam+ beads Good finish ph Antimicrobial effect.

4 Background: Surfactants in skin cleansing *Datamonitor 4

5 What are Skin Cleansers? Skin cleansers are primarily a designed combination of surface-active substances [i.e. emulsifiers /detergents / surfactants / soaps], that lower the surface tension on the skin and removes dirt, sebum, microorganisms and exfoliated corneum cells in an emulsified form. Ideal skin cleanser should do the above sensorially without irritating, damaging or disrupting the skin barrier lipids and the moisture skin barrier. 5

6 What is the role of performance care ingredients? During cleansing there is a complex interaction between the cleanser, the skin moisture barrier & skin barrier lipids. Humectants, emollients and bio-functional ingredients are incorporated in cleansers to restore barrier function & provide moisturization and higher order beauty benefits during & after rinse-off. 6

7 Current SKIN Cleansing Compositions Sensory experience is a key differentiator: Functional and clinical performance is a key differentiator S,D S, S, F Sensory Ingredients [Fragrances, Beads..] Moisturizing & Beauty Components Minimize irritation, Preserve barrier lipids Maintain protective acid mantle of skin S, S, F, M Cleanser Base [Surfactants & Structurants] ASI contributes to all aspects of pyramid 7

8 Key elements of SKIN Cleansing Science 8

9 Skin cleansing may disrupt or disturb the moisture skin barrier, affect the skin surface ph, and irritate the skin [bind to protein domains] The stratum corneum (SC) can be represented by a brick wall composed of: Surface lipids: squalene, ceramides, triglycerides, fatty acids and cholesterol synthesized by sebaceous glands [breakdown from sweat, sebum, & exfoliated corneum cells] Bricks : corneocytes surrounded by a cornified envelope, linked together by corneodesmosomes Mortar : intercellular lipids The structure and function of the stratum corneum G. K. Menon et.al International Journal of Pharmaceutics 435 (2012) 3-9 The skin barrier in healthy and diseased state J.A. Bouwstra,et.al / Biochimica et Biophysica Acta 1758 (2006)

10 C A. Micelle B. Swollen micelle-microemu lsion C. Emulsion Cleanser Base: Surfactants and Structurants 1. Minimize skin irritation, 2. Preserve barrier lipids 3. Maintain protective acid mantle of skin 10

11 Types of Surfactants R O C NH _ + + _ CH 3 (CH N + 2 ) 3 [Amphoteric] Anionic Cationic CH 3 CH 2 Zwitterionic O C O - M + APG: C 10 G 1 Hydrophobic part: alkyl chain Nonionic Lowers interfacial tension Creates new interfaces Competitive binding potential HO OH Hydrophilic part: glucose group Targets defects and exposed surfaces Posseses Solubilization potential for non-polar oily materials O O H OH 11

12 Method to study surfactant micelles Zeta Nano is used for the measurement of the size, zeta potential of colloids and nanoparticles Laser Doppler Micro-electrophoresis is used to measure zeta potential. An electric field is applied to a solution of molecules, micelles or a dispersion of particles, which then move with a velocity related to their zeta potential. This velocity is measured using a patented laser interferometric technique called M3-PALS (Phase analysis Light Scattering). This enables the calculation of electrophoretic mobility, and from this the zeta potential and zeta potential distribution Zeta potential [mv] correlates directly with surfactant irritation potential towards SKIN during cleansing Lips A, Ananth KP, Vethamuthu et.al. Role of surfactant micelle charge in protein denaturization and surfactant-induced skin irritation, in Surfactants in Personal Care Products and Decorative Cosmetics, Vol. 135 (2007)

13 Normalized Counts Zeta Potential Distribution of Surfactant Micelles Harsh to Skin Micelle surface potential Zeta Potential (mv) 1% SLES 1EO 1% CAPB MACKAM C-37HP 1% APG: Plantaren 2000 NUP 1% K-Alkyl Carboxylate 13

14 Importance of Zwitterionic Surfactant + _ Zeta potential varies with ph Micelle radius remains same ~ 3nm Betaine is used for mild cleansing & structuring 14

15 Dynamic Light Scattering (DLS) 15

16 Lipid solubilization potential scales with Surfactant micelle size Core Micelle solubilization potential Z-Average (r.nm) Surfactant micelles that show low irritation scores may cause high lipid damage 16

17 During cleansing surfactants have potential to intercalate into intercellular lipid bilayers: Aids in de-lipidation of SC Lipids [FA>Chol>>Cer] The Mortar is composed of ceramides (50%), cholesterol (25%), fatty acids (15%) and cholesterol sulfate (2-5%) Lipids are organized in bilayers and attached to corneodesmosomes Lipidic bilayer s role is to retain water and regulate electrolyte movement (related to skin hydration and the appearance of healthy skin) Stratum corneum fatty acids:their critical role in preserving barrier integrity during cleansing, KP Ananthapadmanabhan et.al International Journal of Cosmetic Science, 2013, 1-9 The role of epidermal lipids in cutaneous permeability barrier homeostasis, Kenneth R. Feingold, Journal of Lipid Research Volume 48,

18 Minimize Drying potential: Lipid solubilization of surfactant micelles % Dissolution of Stearic acid or Cholesterol per g of surfactant H A R S H t o L I P I D S HO Cholesterol Core Stearic acid OH O Stearic acid Cholesterol 0 APG SLES CAPB NaL Water Ability of surfactant micelles to solubilize lipids Lipid type influences micelle solubilization potential 18 K. Subramanyan & KP. Ananth Personal Cleansing, in Handbook for Cleaning / Decontamination of surfaces, Vol. 1(2007)

19 Strategies to reduce SKIN irritation & lipid damage Balancing surfactant interactions with skin proteins & barrier lipids during cleansing is essential Lower surfactant micellar charge and increase head group area by mixed surfactant design [HPMC] Pre-saturate surfactant micelles with lipid analogues to minimize de-lipidation of endogenous lipids Test hypothesis with Castoryl Maleate for clear body wash 19

20 Hydroxypropyl Methylcellulose [Benecel ] HPMC is a nonionic, naturally derived, multi-functional polymer that can be used in a variety of applications It enhances Skin Rinse-off formulations through: Improved viscosity and stability Improved foam build and stability Improved mildness Enhances fragrance retension & bloom Provides slip Variations in molecular weight and substitution levels allow formulators to dial into desired formulation characteristics 20

21 Idealized Structure of Hydroxypropyl Methylcellulose Benecel Series % OCH3 % POOH E Series K Series

22 Particle Sizing Measurements-Benecel TM E Series Benecel Type Primaflo % in DI Water E4M-0.1% in DI Water Size-Avg. r.nm P di Size Peak1 r.nm Size Peak 1 Area% Size Peak 2 r.nm Size Peak 2 Area % Primaflo MP 3295A shows larger size distribution of particle radius than Benecel E4M. Both show a medium poly-dispersity index (P di <0.5) 22

23 Irritation potential reduction: Control: No HPMC With HPMC- E4M Average Zeta Potential (-66mV) Average Zeta Potential (-28mV) HPMC E4M reduces irritation potential in 10:2 SLES2EO: CAPB base Zeta potential of surfactant micelles correlates directly with Zein solubility and surfactant-induced skin irritation potential of cleanser surfactants [ Role of surfactant micelle charge in protein de-naturation and surfactant-induced skin irritation in Surfactants in Personal Care Products and Decorative Cosmetics, surfactant science series volume 135, CRC press 2007] 23

24 Zeta potential / mv HPMC E4M moves mildness profile of SLES:CAPB towards SLES free liquid cleansers but with superior foaming performance H A R S H t o S K I N Higher Permeability of SC ph of Cleanser Base SLES-Free -23mV Superior Foam SLES/CAPB -28mV Soap Base -66mV 10:2+ E4M 10:2 Base -100 Superior lather/easy rinse 24

25 In-Vitro Skin Irritation Study using Re-constructed Human Epidermis [RHE] RHE Tissue Day 1: Pre-incubation Day 2: Application & Rinsing Day 3: Cell viability measurement and Quantification of Interleukin-1alpha [IL-1a] * Bauza, E., Capallere, C., Arconi, M. in Report MA SR-Body Wash Formulations-RHE Irritation Test, Vincience Lab, France * SKINETHIC Skin Irritation Test 42bis- Standard Operating Procedure SKINETHIC SKIN IRRITATION TEST 42bis METHOD FOR THE PREDICTION OF ACUTE SKIN IRRITATION OF CHEMICALS: 42 MINUTES 25 APPLICATION + 42 HOURS POST-INCUBATION, 2009.

26 Human IL-1a Immunoassay Results: Tested in PBS [IL-1a] P -[IL-1a] PBS pg/ml Viability % Control Formulation 10/2 SLES/CAPB Formulation B 10/2 SLES/CAPB 0.2% HPMC E4M Formulation C 10/2 SLES/CAPB 0.2% HPMC E10M M I L D E R P R O D U C T Mean [IL-1α (pg/ml)] = Mean [IL-1α treated tissues] Mean [IL-1α negative control tissues] 26

27 Pre-saturate micellar core Lipid analogue Pseudo-ceramide lipid structuring Deposition from rinse-off products Quantifiable, lasting moisturization Visible benefits Maleic Anhydride/ Castor Oil Adduct (1:1)-[RMT] Solubilized 0.5% RMT in SLES1EO:CAPB:APG micelles- Clear Body Wash Base O O O O OH H 2 CO H CO H 2 CO O O OH OH 27

28 RMT-solubilized micelles reduces charge & aids in glycerol deposition Free Micelles RMT solubilized Micelles Core RMT reduced Zeta potential to between -20 to -30 mv Micelle radius was increased to ~3 nm using APG as the ternary surfactant 28 Formulations by Diane Kennedy & Cielo Carrion-Trujillo

29 Change in hydration Change in skin hydration after 1 and 2 weeks * (p=0.04) washes 10w+8washes Corneometer 12 panelists -2 Twice daily -4 Hydration measures -6 wormt wrmt Initial After 5 days After 9 days 29 Consumer studies by Cenk Uzel, Stacey C

30 Foam Design: Application to skin & Rinse-off profile Foam films + Cmc to ppm ppm Mixed micelles Monomers 30

31 Foam kinetics & performance parameters Foam kinetics experiments Prepare 2% solutions Speed of foam creation Foaming power-maximum volume Double walled reservoir for conditioning the sample Titration experiments Add 50uL after each stirring interval 15 times Measure foam height for 25 stirring intervals Measure foam decay for 3 minutes 31 Software SITA foam Dispensing System

32 Foam Volume AVG (ml) Instrumental: Body wash foam evaluation Custom foam optimization Test parameters Number of Measurements SLES/CAPB+Oil ph=6.5 Soap base ph=9.25 SLES-Free ph=5.5 Foamability / Speed to lather Maximum foam volume Quality of foam- e.g. creaminess Foam stability profile Capability to screen for foam boosting ingredients Screening & selection of Moisturizing and fragrance ingredients 32

33 Foam Volume / ml Impact of ASI emollients on foam creation Ceraphyl 41 is a foam booster INCI: C12-C15 Alkyl Lactate Base Ceraphyl 31 Ceraphyl 41 Ceraphyl 494 Ceraphyl 45 Ceraphyl Generates luxurious foam and softens & soothes skin

34 Foam Volume / ml Impact of ASI emollients on foam stability 210 Ceraphyl 494 is a foam stabilizer [INCI: Isocetyl Stearate] Base Ceraphyl 31 Ceraphyl 41 Ceraphyl 494 Ceraphyl 45 Ceraphyl Create Ceraphyl blends for moisturizing impact 150 0:00 0:10 0:20 0:30 0:40 0:50 1:00 1:10 1:20 1:30 1:40 1:50 2:00 2:10 2:20 2:30 2:40 2:50 3:00 Foam and Foam Films: Theory, Experiment, Application, D. Exerowa, P.M. Kruklyakov, in: D. Möbius, R. Miller (Eds.), Studies in Interface Science, Elsevier, Amsterdam,

35 In-Vivo Rinse-off Foam Characterization Protocol Protocol Operator keeps hands under flowing tepid water for 2 min 2g of liquid soap is used by operator to hand wash for 30s by shearing and rubbing. Foam is recovered and imaged by close-up photography Images are treated by Canny edge detection for foam bubble delineation and threshold -filtered for object detection. Circular objects (aspect ratio between 0.4 and 1.0) are detected and counted in Image Pro Plus The histograms of bubble objects are extracted and represented 35

36 Examples SoftSoap (Ocean fresh men) Axe Revitalizing Gillette Odor Shield Lux Velvet Touch Axe Sport Blast RightGuard TotalDef 36

37 Mapping Foaming performance Foam density: Average number of bubbles / mm2 Dense foam: d=1.6 Large loose foam: d=0.2 Benchmark commercial bodywashes Understand relevant parameters Design novel foams with superior benefits 37 Foam mapping by Germain Puccetti

38 Foam Viscosity protocol at shear rate 300s -1 40mm stainless steel cone and plate was used at 1mm gap. Viscosity at 300s -1 shear rate is measured for 1 minute duration at room temperature. 38

39 Design synergies between structuring, sensory & deposition polymer/micelle complexes Enhance deposition of Lamellar gels, Pro-Lipids & Bio-functionals Post-wash hydration & beauty benefits Polymer-micelle intrapolymer complexes, Deposition efficiency of actives Homogenous film formation Smooth, soft, & silky feel Barrier repair & beauty benefits Long lasting moisturization 100 nm Vethamuthu et.al.cryo-tem of Polyelectrolyte-micelle complexes. Journal of Colloid and Interface Science 1997, 186 (2),

40 Normalized Counts Polymer-Micelle Complexes INCI Name: Cetyl Hydroxyethylcellulose[HM] Zeta Potential Distribution - Natrosol Polysurf AquaCat Conditioneze 7MP Low MW cationic guar + 10% PQ-7 [Liquid] Conditioning and Clarity PolyQuaternium-7 Charge density~ Establish synergy or antergy with surfactant mix without the presence of structuring polymer Zeta Potential (mv) 40

41 Normalized Counts Polymer Synergies : Inter- Polymer complexes with HPMC- Benecel 200M HM-HEC[Hydoxyethyl Cellulose] Non-stringy flow Non-tacky skin feel Zeta Potential Distribution HPMC-200M Aquacat Conditioneze 7MP Natrosol Polysurf 88 nm 100 nm 102 nm Aquacat CG518 Conditioner & skin softener Skin feel without build-up PolyQuat 7: Conditioneze 7MP Non-stringy flow Silky skin feel Zeta Potential (mv) 41

42 Fragrance design, quality & impact are key for customer brands & image High initial impact out of bottle f(a w ) : non-ideality in water Top notes lost in minutes, f(a m ):non-ideality in micelles Middle Notes Bloom in shower Long lasting fragrance Klogp f(a m ):non-ideality in microstructure Base Notes Base dependent, Fragrance oil composition, ph, Carriers & Additives 42

43 Fibers vs twister Fragrance 1 43

44 Extraction Time Fragrance 1 44

45 Release profile from artificial skin washed with a shower gel formulation 45

46 Challenges - Summary Rheology Modifiers-& Structurants In-shower Moisturizers Foam Management Fragrance deposition Improving Formulation Mildness SKIN Cleansing Innovations Delivering Beauty Benefits 46

47 THANK YOU Questions? 47

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