Retinoic acid and hydroquinone are whitening substances which are often used in
beauty cosmetic cream. Overuse of those substances may cause redness on the skin
and hyperpigmentation. This study has purpose to validate the method of Thin Layer
Chromatography (TLC) Densitometry for retinoic acid and hydroquinone
simultaneously. This method employed 60 F 254 of silica gel plate as the silent
phase, n-hexane: acetone (3:2) as the moving phase, and methanol as the solvent. It
was measured in the maximum wavelength 293 nm. Having the correlation
coefficient value of single retinoic acid, single hydroquinone, simultaneous retinoic
acid and simultaneous hydroquinone were respectively 0.993; 0.9995; 0.9941;
0.9994 it was revealed that this method has good accuracy and linearity. It was found
to be precise because the value of Relative Standard Deviation (RSD) were
respectively 4.69%; 2.70%; 3.827%; 3.089%. It was also found the limit detection
were respectivly 0.058; 0.020; 0.058; 0.0218 μg and limit quantitation were
respectively 0.245; 0.068; 0.194; 0.060 μg. It was found to be accurate because the
value of Recovery were resvectively 97.22%; 98.21%;94.98%; 108.32%.The
etiquette percentage was respectively 100.46%; 100.62%; 96.25%; 100%. Based on
those results it can be concluded that there is no difference between single and
simultaneous treatment, while there are two differences between them in term of Rf
and the width area.