Summary: | 碩士 === 朝陽科技大學 === 應用化學系碩士班 === 98 === 4MSK(4-methoxy salicylic acid KCl) is one kind of whitening medicinal ingredients, which is derived from salicylic acid. 4MSK is ionized when dissolved in the water, which is stable in the acidic buffer condition. When skin was seriously suffered by the ultraviolet radiation to result in the abnormal cuticle of skin and arise from the formation of melasma and freckles. 4MSK can help to treat and improve these skin disease symptoms and restrain the formation of melanin and prevent the production of melasma and freckles.
In this research, a HPLC method was developed to determine the whitening ingredient of 4MSK in hydrogel mask. The mobile phases were prepared with 0.1 % H3PO4 buffer solution adjusted at pH 3 and methanol with the ratio of 40 to 60. Chromatographic methods were performed with a HPLC system equipped with ODS Hypersil 250×4.6 mm(5μm) column with UV/Vis absorption set at 254 nm, flow rate set at 1.0 mL/min and an injection of 10 μL as well as each runtime about six minutes.
In the result of analytical method validation, the linear regression coefficient (R2) was 0.9998, the relative standard deviations(RSD) of precision experiments were between 0.16 % ~ 0.69 %, and the recoveries of accuracy experiment were between 98.7 % ~ 98.9 %.
In the tests of transdermal penetration, the hydrogel masks of 4MSK were placed in nylon membrane and pig skin to do penetrating experiments, the release rates of 4MSK for three hours for nylon membrane and pig skin were 28.24 % and 17.87 %, respectively. The relative standard deviations(RSD) of penetration tests for nylon membrane and pig skin were 6.16 % and 6.71 % below, respectively. The results of penetration tests can be used as the reference of transdermal medicine.
In this experiment, the 4MSK hydrogel mask was placed in the room temperature condition( 25±2℃) and the accelerated condition(40±2℃) for six-month stability tests, the content of 4MSK was declined to 98.4% in the room temperature test and was declined to 92.5% in the accelerated test at the sixth month.
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