They use a 1 % . Meaning every 100ml of lotion you have 1 gram ( 1000 mg ) of Cetirizine .
They use Water, Ethanol and don't remember what else. Anyway, like it was already posted here with an study, ethanol is not the best vehicle for cetirizine. In theory water alone will disolve all. To be honest, I don't know if the alcahol is necesary for penetration . But, for just in case, you can do a lotion with 80 % water and 20 % propilen glycol .
Thanks ! do i just mix them all and let it stand like 24h before applying or i have to crush and filter the pills ? is cetirizine tablets or capsule ?