SinodosChemistry

Our clients asked us to evaluate the compositions of specific cosmetic formulations with ‘anti- aging’ claims. A high number of active components has been investigated, both in regards to their activity and their allowed concentrations in the EU and Canadian markets. We had to:

 

n  Evaluate the allowed concentrations of salicylic acid in cosmetic products of interest, since a confusion seemed to exist between the 0.5, 2, and 3% concentrations mentioned in various regulations and products – SOLVED

 

n  the concentration of salicylic acid in very popular commercial neck firming creams, with very rich composition profiles as seen below (SOLVED):

water, hydroxyethyl urea, glycerin, dimethicone, hydroxyethyl acrylate/sodium acryloyldimethyl taurate copolymer, steareth-21, jojoba esters, petrolatum, selaginella lepidophylla extract, aloe barbadensis leaf juice, salicylic acid, stearyl alcohol, glyceryl stearate, isohexadecane, ubiquinone, whey protein, jojoba oil/macadamia seed oil esters, phytosteryl macadamiate, bisabolol, pyrus malus (apple) fruit extract, citrullus lanatus (watermelon) fruit extract, phytosterols, panthenol, tocopheryl acetate, magnesium ascorbyl phosphate, sodium lactate, methyl gluceth-20, C12-15 alkyl benzoate, sodium PCA, cetyl alcohol, hydrolyzed jojoba esters, squalene, cetearyl alcohol, stearamidopropyl PG-dimonium chloride phosphate, lens esculenta (lentil) fruit extract, methylparaben, ethylhexylglycerin, propylene glycol, tocopherol, EDTA, zingiber officinale (ginger) root extract, potassium hydroxide, polysorbate 60

 

n  the different performance of 0.5% and the higher percentages in neck firming creams – SOLVED

 

n  the additional functionalities of increased levels of AHAs and BHAs in such creams – SOLVED

 

Addition of more AHAs and BHAs can increase the effect of the cream, provided that they include exfoliants. A concern is the oil- solubility vs water- solubility between the two. Most manufacturers choose to use only AHAs OR BHAs for this reason and for the skin- aimed reason. To combine those, successful approaches exist:

-         Use of carriers such as PEG400, β- Cyclodextrin derivatives, etc

-         Supersonication

-         Emulsification with suitable surfactants

-         Encapsulation

 

Each method works best depending on the exact system of interest. Best AHAs and BHAs for the current product would include:

-         Malic (mostly efficiency enhancer in synergy; its individual efficiency is low)

-         Mandelic (similar synergy- preferred case as above)

-         Citric acid (highly efficient on its own as well)

BHAs commonly used (betaine salicylate, salix alba, etc..) tend to turn to salicylic acid (at some degree) and they could impact the overall salicylic acid concentration.

 

n  The effect of niacinamide addition on salicylic acid: synergy or competition? - SOLVED

 

n  Allowed levels of glycolic acid and lactic acid in body creams in EU and Canada – SOLVED

 

n  Process for backing up claims via clinical trials and self- assessment – SOLVED

 

n  Costs of clinical trials in different regions around the world - SOLVED