Presentation on theme: "Yi-Hui Lin1, Shou-Mei Wu1,2,3*"— Presentation transcript:
1Yi-Hui Lin1, Shou-Mei Wu1,2,3* Simultaneous determination of arbutin, kojic acid and hydroquinone in skin lightening cosmetics by MEKCYi-Hui Lin1, Shou-Mei Wu1,2,3*1Graduate Institute of Pharmaceutical Science, College of Pharmacy, Kaohsiung Medical University, Kaohsiung, Taiwan2Faculty of Fragrance and Cosmetics, College of Pharmacy, Kaohsiung Medical University, Kaohsiung, Taiwan3Faculty of Pharmacy, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 807, Taiwan
2AbstractA simple method of micellar electrokinetic capillary electrophoresis (MEKC) was established for simultaneous analysis of arbutin, kojic acid and hydroquinone. Untreated fused-silica capillary was operated using phosphate buffer (20 mM, pH 6.5) under 20 kV and detection at 200 nm. Baseline separation was attained within 9 minutes. The quantitative ranges were μg/mL for arbutin, μg/mL for kojic acid and 8-80μg/mL for hydroquinone with correlation coefficients ≥ The R.S.D. and R.E. were all less than 3.0 % for the intra-day and inter-day analysis, and all recoveries were greater than 99 %. The limits of detection was arbutin 5.4 μg/mL, kojic acid 7.1μg/mL and hydroquinone 2.2 μg/mL (S/N = 3, hydrodynamic injection 5 sec). Our method was applied to determine the quality of commercial cosmetic. Assay results were all within the labeled amount of %.
3Arbutin (AR) 4-hydroxyphenyl-β-D-glucopyranoside IntroductionArbutin (AR)4-hydroxyphenyl-β-D-glucopyranosideextracted from leaves of common bearberryIt can compete with L-dopa for receptor site on tyrosinase and hinders the oxidation of L-dopa to L-dopaquinone, thus, can inhibit the formation of eumelanin and phaeomelaninoften used in skin care products as a lightening agent
4Hydroquinone (HQ) 1,4-benzenediol IntroductionHydroquinone (HQ)1,4-benzenediolIt can produce reversible depigmentation of the skin by suppression of melanocyte metabolic processes
5Kojic acid (KA) 5-hydroxy-2-(hydroxymethyl)-4H-pyran-4-one IntroductionKojic acid (KA)5-hydroxy-2-(hydroxymethyl)-4H-pyran-4-onea natural substance produced by fungi or bacteria,such as Aspergillus, Penicillium or Acetobacter sppIt is able to inhibit the creolase and catecholase activities of tyrosinase.can be used in cosmetics to prevent serious sun-burning caused by an accumulation of melanin
6According to Department of Health, Taiwan, R.O.C IntroductionAccording to Department of Health, Taiwan, R.O.CIt also recommended that HQ should be used under prescription because long term used of high concentration hydroquinone (over 5 %) may cause severe side effects including dermatitis, erythema, leukoderma, burning and hyperpigmentation.IngredientsLimit1、Kojic Acid (5-Hydroxy-2-Hydroxymethyl-4H-Pyran-4-one)2%2、Arbutin (4-hydroxyphenyl-β-D-glucopyranoside)7%
7Aim of this studyTo develop a rapid, sensitive and quantitative assay for the simultaneous determination of AR, KA and HQ by capillary electrophoresis.Optimization, validation and application of this method were investigated.
8Materials AR (98%) KA HQ Urea (I.S.) Sodium dodecyl sulfate NeoStrata® pigment lightening gel (Princeton, NJ, USA)Shiseido® white lucent (Tokyo, Japan)Grape® quincare ointment (Chung-Li, Taiwan)
9CE SystemA Beckman P/ACE System 2200 equipped with a filter UV detectorThe fused-silica capillaries:I.D.= 50 µm; Lt= 57.0 cm; Ld= 50.0 cmPhosphate buffer containing SDSApplied voltage: 20 kVTemperature: 25 ˚CWavelength for detection: 200 nmHydrodynamic injection pressure: 50 mbar, 5 sec
11Figure 1. Effects of SDS concentrations on the migration of AR, KA and HQ each at 200 μM. Electropherograms: (A) overlapping peaks from separation in the absence of SDS, (B) with 60 mM SDS, (C) with 80 mM SDS, (D) with 100 mM SDS.
12Table 1. Regression analysis for the determination of AR, KA and HQ. Analysis Regression equation Coefficient ofcorrelation (r)intra-dayaARKAHQinter-daybY=(5.2316±0.0166)X+(0.0149±0.0020)Y=(6.0875±0.0336)X+(0.0023±0.0046)Y=(11.469±0.0249)X+(0.0116±0.0032)Y=(5.2295±0.0516)X+(0.0109±0.0053)Y=(6.0724±0.1173)X+(0.0018±0.0053)Y=( ±0.1129)X+(0.0009±0.007)0.99980.99940.99970.9996* Concentration ranges for the intra- and inter-day analysis:AR: mg/mlKA: mg/mlHQ: mg/mla The regression equations of intra-day analysis were calculated from the assay values of prepared standards on a single day (n=3).b The regression equations of inter-day analysis were calculated from the assay values of prepared standards on a single day (n=5).
13Table 2. Precision and accuracy for the determination of AR, KA and HQ. ConcentrationRSDREknowfound(mg/ml)(%)Intra-day analysis (n=3)AR0.050.0504±0.00061.200.860.090.0904±0.00040.480.410.160.1609±0.00070.430.57KA0.030.0299±0.00062.03-0.340.070.0697±0.00081.13-0.410.0891±0.00070.77-0.95HQ0.0150.0150±0.00010.010.0292±0.00051.75-2.630.0698±0.00071.05-0.23Inter-day analysis (n=5)0.0503±0.00102.050.700.0902±0.00091.040.280.1606±0.00100.610.350.0296±0.00082.59-1.210.0693±0.00091.28-0.960.0893±0.0009-0.750.87-0.140.0292±0.00062.01-2.800.0701±0.00081.170.08
14Table 3. Recovery of AR, KA and HQ added to the commercial formulation ConcentrationRecoveryspikedfound(mg/ml)(%)AR–0.0303±0.00020.020.0512±0.0008104.550.070.1017±0.0015102.000.160.1928±0.0012101.55KA0.0222±0.00090.0421±0.001099.440.040.0631±0.0002102.160.0924±0.0005100.30HQ0.0109±0.00020.0313±0.00020.0511±0.00020.060.0720±0.0005
15Table 4. Quantification of AR, KA and HQ in marketing cosmetics Samples(Labeled amount)Amount foundAR(3%)13.0022.9933.01MeanSD0.0068KA(2%)2.012.052.042.030.0152HQ(20mg/g)19.9420.2720.3520.190.1778
16ConclusionsThis method can be used for the simultaneous determination of arbutin, kojic acid and hydroquinone and was successfully applied to the content assays of skin whiting cosmetics.