To undestand the functioning of cold gels for relaxing sore legsI moved the general question about the topic here [1]. I am trying to be able to identify price-efficient that is effective and not-expensive cold gels by understanding their function first. I would like to be able to make such gels by myself too, since it does not seem to be difficult.
Some examples of brands: Ice Power (North Europe), Horse Power (North-Europe), Deep Freeze Cold Gel (UK), Cold Gel, Ratiopharm (Israel, Germany), and Freeze Rx Inc. Penetrating Long Lasting Pain Relief [2] (USA).
The active component of the cold gel is menthol, the table [4]. It makes the analgesic effect in relieving the pain of the sore muscles. However, I do not what is the limit for the potens effect that is good relieving effects of the effective menthol as percentages of the gel.
The maximum interval of the effective menthol as percentages in the gel for potens effects is not relevant here, since menthol is used only to relieve minor pains [5] that is non-neural ones and no damages in the tissues?
Deep Freeze Cold gel [6]'s active main component is Racemic Menthol 2%, while Ratiopharm's product 3%. What is the effect of the composition of the left and right side enantiomers to the potens effect? The other cold gels may not have racemic [7] methanol, which is more expensive to make than non-racemic-and-non-pure-enantiomeric one.
Horse Power has same intervals of ethanol-menthol than Ice Power according to the safety reports at 22.03.2005 for Horse Power Cold Effect and 15.04.2010 for Ice Power Cold Gel: menthol 3-15% and ethanol 5-15%
NB the two products use ethanol probably only as an inactive component too, since most of the ethanol apparently evaporate from the skin, in contrast to the competitor [8]. What is the main purpose of ethanol in the gel? It is probably only used as a preservative.
There is no lipids in the component list of Orion's Jomo cold-gel here:
ethanol, menthol, water, propylene glycol, methylsulfonylmethane, eucalyptys oil, carbomer, glycerol, triethanolamine, methylparaben, silicon dioxide, propylparaben
The components are rather different from the product of the competitor [9]:
aloe vera extract, carbomer, decyl polyglucose, deinoized water, grapefruit seed extract, green tea extract, lemon peel extract, queen of the prairie extract, rose water, sodium hydroxymethylglycinate, vegetable glycerin, witch hazel, yucca extract
How should you select the inactive components in selecting the given cold gel?
The warning signs of the two cold-gels are R 38: irritates skin, R 11: burns easily and X_i: irritating so there does not seem to be any severe effect on your health although you use the stronger Horse Power.
I have been using Horse Power because of its effectivity and low price so that I need only little to use it. Its inactive components seem to be harmless: probably eucalyptys oil similarly as Orion's product in allowing the penetration of the skin. The thing that can make it harmful is the relative composition of the inactive components. However, the pieces of information is hidden by the manufacturer.
There may also be other things besides of lipids such as eucalyptus oil to allow more the penetration of the skin, since the skin of the horses is thicker than that of human. One possibility is that Horse Power has only more of the lipid, probably eucalyptus oil, in that case no danger to human. I have discussed about the product and a similar product of horses with the chemists of their manufacturers: they said to me that just use the horse product, it is really like the human one. However, I did not get any explanation for their claims.
