Chapter 17 - Application of Fragrance - Technical Aspects Flashcards
What is the difference in the use of scent between fine fragrance with soaps, antiperspirants and shampoo?
Scent is the primary function of fine fragrances.
Scents for other application are secondary functions
What are the 4 main technical aspects to consider for formulating a fragrance?
(1) Odour
(2) Solubility
(3) Stability
(4) Compatibility between fragrance and product ingredients
What is the difference between denatured ethanol B (DEB) and ethanol?
Denatured, cheaper tax-free. (Gives a bitter taste so people do not drink)
What is the use of PPG-20 methyl glucose ether?
Moisurizing agent with fixative properties
What is the use of Benzophenone-2?
UV absorber/filter
How can we tell the strength of the product?
Alcohol content / alcohol + water content
What is the use of titanium dioxide?
Give white colour
Make the product opaque
What are the possible formulations issues/concerns with soap?
Colour of soap:
- Match colour to fragrance type
Discolouration in white soaps:
- Too much vanillin (use small concentrated amounts or non-discolouring synthetics)
- Chemical reaction due to high pH of soap
- Reaction accelerated by light
Stability testing
Describe what are aerosol antiperspirants and the consitituents of it?
Propellant gas:
- Propane-butane blend
Antiperspirant active:
- Powder in volatile silicone fluid suspension (Require special valve & actuator system)
Fragrance/perfume:
- Must be stable in aerosol antiperspirant formulation
What are the key ingredients in the formula for a dry aerosol antiperspirant and what are their uses?
- Aluminium chlorhydrate powder: Antiperspirant active - suitable particle size distribution for effective dispensing
- Bentonite: Thickener to help ensure particle are kept in suspension
- Volatile silicone fluid (Cyclomethicone): Sufficiently volatile to evaporate from skin; soluble in propellant blend
- Isopropyl myristate: Skin conditioning agent (Emollient)
- Fragrance: Stable in antiperspirant formulation (usually acidic)
What are the possible formulations issues/concerns with aerosol antiperspirants?
- Can cause some fragrance ingredients to undergo chemical reactions.
- Trace of metal ions in aerosol product can discolour perfume
- Odour balance of fragrance may be altered (different from neat fragrance oil); biased towards top notes (volatile)
- Potential of corrosion (Finished product in production specification cans - storage testing)
What are the common ingredients found in frequently-used shampoos?
1) Sodium lauryl ether sulfate - high foaming anionic detergent
2) Cocamidopropylbetaine - Mild amphoteric betaine detergent (Lower irritation potential of SLES)
3) Panthenol - Provitamin B5 (to thicken and help repair damaged hair)
4) Sodium chloride - Thicken detergent system
5) Glycol distearate & laureth-4 & Cocamidopropylbetaine - Cold-mix opacifying concentrate for attractive, white, pearly look.
What are the possible formulation issues with shampoos?
1) Fragrance ingredients - may cause change in shampoo viscosity
2) Chemical reaction between fragrance ingredients and actives in shampoos - discolouration or off-odor
What is the use of stability testing and how is it conducted?
1) Accelerated test protocols
- Predict likely shelf-life (minimum 2 years)
- Identify potential problems
- 12 months at 20 degrees; 6 months at 30 degrees (Arrhenius rate equation - 10 degree, reaction doubles)
What are the minimum standards for stability testing?
- Generally tested at (0-4, 20 or 25, 37 degrees for 12 weeks)
- Additional testing at 45-50 degrees (not for aerosol)
What is the use of humidity testing and how is it conducted?
1) Testing in high humidity conditions for products to be packaged in permeable materials such as paper or plastic
- Test conditions (37 degrees at 70% and 40 degrees at 80%)
What is the use of light testing and how is it conducted?
1) Use of UV cabinets (samples put under UV light from Xenon arc lamps)
- Exposure to 6h of 100W lamp to detect changes likely to take place in around 3 months of daylight testing; the disadvantage is the UV cabinet can become quite hot which might not give a true representation of normal daylight.
2) Light stress chambers:
- Temperature can be controlled fully
- Different types of lights can be used.
When are samples usually assessed for stability testing and what are tested?
- 12 weeks
(Usually also after 4 or 6 weeks period) - Odour: test for odour intensity and perfume character
- Physical appearance: evaluated for discolouration, separation, precipitation, viscosity change
What are the scales for assessing perfume character and odour intensity?
Perfume character: - (A): No change, excellent - (B): Very slight modification - (C): Some modification but acceptable - (D): Modified, unsatisifactory - (E): Unrecognisable Odour intensity: - (1): No change - (2) Slight weakening - (3) Some loss of impact but acceptable - (4) Weak, unsatisfactory - (5) Odourless or extremely weak
What are the standard test conditions (temperature) and duration of testing of odour testing?
- 0 degrees for 12 weeks
- 20 degrees for 12 weeks
- 37 degrees for 12 weeks
- 50 degrees for 4 weeks (Not for aerosol)
What are the standard test conditions (temperature) and duration of testing of physical appearance testing?
- 0 degrees for 12 weeks
- 20 degrees for 12 weeks
- 37 degrees for 12 weeks
- 50 degrees for 4 weeks
- UV for 6 hours (Not for aerosol)
What are the scales for assessing physical appearance?
Physical appearance:
- (A): No change
- (B): Slight change
- (C): Change but acceptable
- (D): Unacceptable change, e.g discoloration, separation, viscosity change etc.
What are some general tips to store cosmetic products?
- Keep away from direct light sources and heat
- Store in a cool dry place
- Avoid allowing the product to come into contact with air. Close cap firmly after use
- If already open, best to use up within recommended period
