Some Problems in Hair Care Product Formulations and Manufacturing

1. Some Problems in Hair Care Product Formulations and Manufacturing Assoc. Prof. Dr. Pleumchitt Rojanapanthu Pharmacy Department, Faculty of Pharmacy Mohidol University, Bangkok, Thailand

2. Shampoos Thickener and Foam Stabilizer • Electrolytes • Alkalonamides or the alternatives • Polymeric materials

3. Thickener and Foam Stabilizer • Electrolyte • ionic density of the solution • size and shape of micelle • Adding the same cation as that of primary anionic surfactant • Eg: amm.chloride amm. lauryl surphate sod. chloride sod. lauryl ether sulphate

4. Thickener and Foam Stabiliser • Electrolyte should be added as solution (25% W/W) • Avoiding local concentration gelation

5. Viscosity/electrolyte curve for a well-formulated shampoo Preferred viscosity range %electrolyte

6. Shampoos which need Thining • Active matter is high • Contain high levels of electrolytes • Large amt. of some amphoterics are present • Addition of short-chain alcohol or glycol: ethonal, isopropanol • Glycols are preferred (less odor/imflammable)

7. Alkalonamides • Mono-ethanolamide > effective than di- ethanolamide as foam stabiliser and thickener • Disadvantage : waxy solid required hot process of mixing • Among the group of lauric, lauric/myristic and coconut mono- and di-ethanolamide • Lauric mono-isopropanolamide is the most effective thickener and foam stabiliser

8. Alkalonamide alternatives • PEG-6000 distearate • PEG-55 propylene glycol oleate • PEG-120 methyl glucose dioleate • Effective in systems based on some sulphosuccinates, ethoxylated sorbitan esters alkane sulphonates, lauryl sulphates, low level of free fatty alcohols.

9. Polymeric materials • Natural gums: guar, karaya, caragenan, lacus bean Find little use in today’s shampoos • Cellulose derivative: hydroxyethyl cellulose (HEC), carboxymethyl cellulose (CMC), hydroxypropyl methycellulose (HPMC)

10. Perfumes • Simply added after any hot process is complete • Solubilty problem: • Premixing with a suitable solubiliser • Ratio of mixing being determined by trial and error • PEG-40 hydrogenated castor oil is mostly used • Polysorbates may cause thining • Premixing with alkalonamide at < 40 C

11. Preservatives • Most surfactants are already preserved • Chosen preservative system should pass a recognised challenge test in the final formulation • Freshly prepared • Aging • Accompanied by meaningful preservatives assays

12. Opacifier and Pearlisers • Aesthetic reason • Occasionally used technique for unclear product Suggestion method • Buying ready made pearlised base (cheap) • Make dilution adding to shampoo as hot mixing • Buying highly concentrated pearlising agent (more expensive) • Adding as cold mix (2%)

13. Conditioning agents • Back-bone surfactants in shampoos mostly are anionic surfactants • Majority active conditioning agents are cationic surfactants

14. Problem solving • Including more % of amphoteric surfactants • Reducing charge of anionic and cationic surfactants by ethoxylation • Replacing cationic surfactants by using cationic polymer • Adding high level of nonionic surfactant

15. Colour fading • Stability to pH variation and light can be predicted • Interaction between colour and the complexation of modern shampoo base evaluated for each formulation • Natural sunlight (shelf life) • Accelerated conditions

16. Colour fading (con.) • Minimised colour fading by incorporation of suitable UV absorber • Benzophenone – 4 and –2 water soluble absorbers are most popular (0.05 – 0.1%) • Colour should be added as a solution

17. Conditioners • Hair charge surface negative • Anionic surfactants for shampoo (usually C12 /C14) negative charge • Cationic surfactants for conditioner (usually C16 / C18 and quart with C22) positive charge

18. Conditioners (con.) • Some quarts are relatively poorly biodegradable • ‘Ester quarts’is claimed to be better • Properties related to charge density • Highly charged cation more strongly attached to the negative-charged hair surface

19. Conditioners (con.) • On the hair surface: • number., shape and size of fatty acid chain in molecule are the determinant • A quart with two fatty acid chains provides more lubricity than a quart with one • More longer chain >effective lubricant than shorter one

20. Conditioners (con.) • Using single fatty acid chain greasy hair / frequent use • Using twin fatty acid chain on the dried / damaged hair

21. Manufacturing • Simply diluting down a suitable quart with water • The stability and effectiveness maybe limited • The appearance of emulsion may be course and grainy in texture • Low opacity/ the flow has high yield point • Increased viscosity with time • Sensitivity to change manufacturing method

22. Problem solving • Introduction of other waxy component: esters • Decrease H-bonding with OH-_of fatty alcohol • Decrease the viscosity rising • Addition of small amount of oil • Smooth out the emulsion • Increase opacity • Facilitate processing • Easier to obtain repeatable viscosity

23. Problem solving (con.) • Additon of a non-ionic to the emulsion • Can increase grealty in the emulsification • Increase stability due to the formation of mixed micelles and the presence of mixed surfactants at the oil/water interface of the emulsion

24. Bodying Agents • As shampoos, conditioners perceived to be more effective when thick and creamy • Using high levels of fatty alcohols with other waxy esters • Improvement in handling of hair especially when combing

25. Auxilliary Emulsifiers • Depending on HLB • Some quart mols. have emulsifier properties, some are not • Incompatibilty with anionic emulsifiers • Addition of non-ionic are preferred • Recommended to use two emulsifiers (high and low HLB)

26. Thickeners • Cationic emulsion do not usually required thickener • If needed, they usually response to salt in a similar way as shampoo • The method of using thickening must be treated with extreme caution • Irreversible emulsion breakdown should be avoided

27. Suggestions • Add only small amount of salt solution at a time since viscosity will peak at much lower salt level than that of shampoo • Add salt solution at cold emulsion (max 30 C) • Shear rate has effect on the emulsion; moderate shear rate should be used • Try small scale before scaling up

28. Suggestions (con.) • Gum-type thickener: cellulose derivative dominate for clear conditioner • Carbomers incompatibility with cationics

29. Permanent WavingFactor affecting the efficiency of the products • Processing time • Processing temperature • Concentration of reducing agent • Ratio of lotion to hair quantities • Penetration of the lotion • pH • The nature and condition of untreated hair

30. Permanent Waving (con.)Factor affecting the efficiency of the products • Procession time • Should not be longer than necessary • Home perm may be designed for longer processing • Processing temperature • Will be ambient for most products • For hot process: needs external mean of heat or exothermic chem. reaction (mixing before use)

31. Permanent Waving (con.)Factor affecting the efficiency of the products • Concentration of active ingredients • A wide range of concentration is available • Will not be changed during use except by dilution • The ratio of lotion to hair • Insufficient lotion to treat when very long hair is involved

32. Permanent Waving (con.)Factor affecting the efficiency of the products • The penetration of the lotion • Enhanced by the inclusion of surfactant • Mostly non-ionic and anionic • Hydrogen bond breaker: urea

33. Permanent Waving (con.)Factor affecting the efficiency of the products • pH • Too low product doesn’t work well • Too high severe hair damage and high irritation of the skin of scalp • Maximum bond cleavage occurs at pH 9 > 8.5 bond reformation is less complete < 7.5 amt. of bond cleavage is low and reformation is more complete

34. Permanent Waving (con.)Factor affecting the efficiency of the products • - Conventional ammonium thio-glycollate lotion • Approx 9.2+ 0.2 • - pH is currently restricted by law to a max 9.5 and total thio-glycollate to 8% (free acid)

35. Permanent Waving (con.)Factor affecting the efficiency of the products • Hair type and condition • Coarse hair require more severe treatment • Fine and damaged hair require gentle treatment

36. Permanent Waving (con.)Factor affecting the efficiency of the products • Other Variables: • Number and diameter of the roller • Tension of the hair on the roller • The speed at which the operation is carried out

37. Product Evaluation and Testing Methods of testing and evaluating products are essential to confirm that products are met the requirements • In vitro method: lab-based instrumental techniques for initial screening • In vivo method: salon or consumer testings

38. Stability Testing • EC “Cosmetic Directives specify that : “Products should remain safe and effective for two and a half years” The Test Methods: • High and low temperature storage • Freeze / thawing cycling • Centrifugation • etc

39. Compatibility Testing • The compatibility testing should be carried out • Two sets of tests to be runned in parallel • One set in actual containers to be used • The other in inert container, usually glass • Should give valuable comparative data

40. Claim Justification • If there is specific claim, the manufacturer must be able to justify: • Known properties of raw materials • Usage level and condition of use • Lab testing, salon trials • consumer panel test: the no. and type of subjects

41. Product Safety • If a formulation is a ‘standard’ one, no further action is necessary • If new raw material/unusual combinations of materials are used • If any ingredient is present at an unusually high level

42. Product Safety (con.) • The opinion of a qualified dermatologist, ophthalmologist, toxicologist may be an valuable backup to the cosmetic chemist’s judgement • If there is real doubt about the total safety, further testing should be in the form of human volunteer study

43. Thank You Kob Khun Kha