478 JOURNAL OF COSMETIC SCIENCE Table III Relative Standard Deviations (RSDs), Linear Ranges, Correlation Coefficients, and Detection Limits for the Determination of Six Sunscreen Agents by HPLC and UPLC Sunscreen RSD (%) Linear range Correlation agent Instrument RT Peak area (µg ml- 1 ) coefficients (r2) IMC HPLC 0.31 0.27 6.6-105.0 0.9999 UPLC 0.36 0.35 0.9999 OMC HPLC 0.08 0.39 12.2-195.0 0.9999 UPLC 0.11 0.44 0.9999 OS HPLC 0.16 0.27 8.9-142.0 0.9999 UPLC 0.31 0.18 0.9999 OT HPLC 0.35 0.10 5.1-82.0 0.9999 UPLC 0.06 0.16 0.9999 TM HPLC 0.18 0.22 4.9-79.0 0.9998 UPLC 0.33 0.34 0.9999 TS HPLC 0.51 0.21 10.3-164.0 0.9999 UPLC 0.29 0.39 0.9999 Table IV System Stability and Intermediate Precision for the Determination of Six Sunscreen Agents by HPLC and UPLC System stability RSD (%) Sunscreen Intermediate precision agent Instrument RT Peak area RSD (%) assay IMC HPLC 0.33 0.45 0.49 UPLC 0.15 0.23 0.52 OMC HPLC 0.14 0.55 0.44 UPLC 0.29 0.49 0.43 OS HPLC 0.14 0.36 0.59 UPLC 0.11 0.28 0.63 OT HPLC 0.20 0.60 0.92 UPLC 0.15 0.54 0.56 TM HPLC 0.10 0.36 0.44 UPLC 0.16 0.33 0.23 TS HPLC 0.12 0.40 0.52 UPLC 0.15 0.38 0.49 RSDs of the HPLC and UPLC data. The RSDs were not more than the maximal acceptable value of 2% in HPLC and UPLC. Accuracy. The accuracy of the proposed system was examined by a recovery test as described above. Table V summarizes the theoretical concentration, the observed con­ centration, and the recovery value. The recovery value was the difference between the observed concentration and the theoretical concentration of the test sample. As the recovery yields fell within (100 ± 2.0)%, all of the recovery yields were regarded as acceptably qualified. Analysis of samples. Ten suncare products that could be available commercially and that contain various combinations of the concentrations of sunscreen agents were assayed

DETERMINATION OF SUNSCREEN AGENTS BY UPLC AND HPLC 479 Table V Theoretical Concentrations (TC), Observed Concentrations (OC), and Recovery for Accuracy Studies by HPLC and UPLC Sunscreen TC oc Recovery agent Instrument (µg ml- 1 ) (µg ml- 1 ) (%) IMC HPLC 43.22/47 .58/5 7 .19 42.88/48.19/57 .57 99.20/101.28/100.67 UPLC 42.99/48.15/5 7 .63 99.47 /101.20/100.77 OMC HPLC 130.97 /143.13/170.97 130.35/145.44/172.57 99.5 3/101.61/100.98 UPLC 130.45/141.96/172.33 99 .60/99.18/100.80 OS HPLC 95.26/108.31/130.35 96.36/109.90/131.97 101.15/101.47 /101.24 UPLC 95 .84/109.18/131.25 100.61/100.80/100.69 OT HPLC 41.5 7 /47 .12/57.45 41.15/47 .57 /5 7. 74 99.00/100.96/100.51 UPLC 41.99/47.95/57.34 101.08/101. 76/99.81 TM HPLC 22.81/25 .23/29. 78 23.13/25.50/29.89 101.64/101.07 /100.38 UPLC 22.93/25.10/29.94 100.5 3/99.48/100.54 TS HPLC 31.28/34.21/41.41 31.05/34.77 /45.54 99.26/101.64/100.32 UPLC 31.33/34.56/41.3l 100.16/101.02/99.76 using the proposed HPLC and UPLC methods in this study. The test data corresponded exactly with the indicated ingredients of the cosmetics. The results are tabulated in Table VI. Table VI Determination of Sunscreen Agents in Suncare Products by HPLC and UPLC Label claim % Found % Found Product UV filter (%, w/w) in HPLC* in UPLC* Cream A IMC 2.0 2.1 2.1 OMC 5.0 5.3 5.3 OS 4.5 4.7 4.7 OT 2.0 2.2 2.2 Cream B IMC 2.0 2.0 2.0 OMC 5.7 5.8 5.7 TM 1.0 1.1 1.0 TS 2.0 2.0 2.0 Lotion A IMC 2.0 2.1 2.1 OMC 7.0 7.2 7.1 Lotion B IMC 2.0 2.2 2.1 OMC 5.0 5.1 5.1 TM 1.0 1.1 1.1 TS 2.0 2.0 1.9 Foundation A IMC 2.0 2.1 2.0 OMC 5.0 5.0 5.0 TS 3.0 3.2 3.1 Foundation B OMC 3.0 3.2 3.2 TS 6.0 6.4 6.2 Makeup base A IMC 3.0 3.1 3.1 Makeup base B IMC 2.0 2.1 3.1 OMC 7.0 7.2 7.0 OS 4.5 4.6 4.5 TS 3.0 3.1 3.1 Lipstick A IMC 2.0 1.9 2.0 OMC 5.0 5.0 5.1 Lipstick B OMC 7.0 7.3 7.2 * Values are the average of 3x determination.