Transcript Permanent Waving (con.)

Some Problems in Hair Care
Product Formulations and
Manufacturing
Assoc. Prof. Dr. Pleumchitt Rojanapanthu
Pharmacy Department, Faculty of Pharmacy
Mohidol University, Bangkok, Thailand
1
Shampoos Thickener
and Foam Stabilizer
• Electrolytes
• Alkalonamides or the alternatives
• Polymeric materials
2
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
sod. chloride
amm. lauryl surphate
sod. lauryl ether sulphate
3
Thickener and Foam Stabiliser
• Electrolyte should be added as solution
(25% W/W)
• Avoiding local concentration
gelation
4
Viscosity/electrolyte curve for a
well-formulated shampoo
Preferred
viscosity
range
% electrolyte
5
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)
6
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
7
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.
8
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)
9
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
10
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
11
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%)
12
Conditioning agents
• Back-bone surfactants in shampoos mostly
are anionic surfactants
• Majority active conditioning agents are
cationic surfactants
13
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
14
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
15
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
16
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
17
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
18
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
19
Conditioners (con.)
• Using single fatty acid chain greasy hair
/ frequent use
• Using twin fatty acid chain on the
dried / damaged hair
20
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
21
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
22
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
23
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
24
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)
25
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
26
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
27
Suggestions (con.)
• Gum-type thickener: cellulose derivative
dominate for clear conditioner
• Carbomers
incompatibility with cationics
28
Permanent Waving
Factor 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
29
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)
30
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
31
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
32
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
33
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)
34
Permanent Waving (con.)
Factor affecting the efficiency of the products
• Hair type and condition
– Coarse hair
require more severe treatment
– Fine and damaged hair
treatment
require gentle
35
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
36
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
37
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
38
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
39
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
40
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
41
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
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