By Tonya A. Howard on Saturday, November 1, 2003 - 11:53 am:
Searching for a method or journal articles to quantify Allantoin in Cosmetic Formulations.
By Anonymous on Saturday, November 1, 2003 - 05:12 pm:
Determination of Allantoin in Biological, Cosmetic, and Pharmaceutical Samples
Authors: Chen, X.B.
Source: J. Am. Oil Chem. Soc. Int
Year: 1996xxxxVolume: 79(3)xxxxPage: 628-635
By Anonymous on Monday, November 3, 2003 - 06:11 am:
HPLC Method for Allantoin Analysis in Skin Creams
This method is largely derived from “Stability-Indicating Liquid Chromatographic Procedure for Determination of Allantoin in Cosmetic Lotion”, Trivedi, Ramesh J., J. Assoc. Off. Anal. Chem. (Vol. 71, No. 2, 1988).
Method
Reagents and Apparatus
(a) Triethylamine-Reagent grade
(b) Acetonitrile-LC grade
(c) Allantoin Reference Standard-98% Purity, Aldrich, A28392-100g
(d) Standard Solutions-Accurately weigh ca 2, 4, and 6 mg reference into 3 separate 50mL volumetric flasks. Dilute to mark with 30:70 Water:Acetonitrile, mix contents well. Filter through a 0.45um syringe filter before running on HPLC.
(e) Sample solutions-Accurately weigh ca 0.6 g of skin cream into a 50 mL volumetric flask. Dilute to mark with 30:70 Water:Acetonitrile, mix contents well. Filter through a 0.45um syringe filter before running on HPLC.
(f) Disposable Syringe Filters-Whatman Autovial 0.45um Nylon, or equivalent.
(g) HPLC System-Waters AMDS, comprised of 2695 Alliance solvent delivery system, autosampler, and column heater; 2996 Photodiode Array Detector; Waters Empower Chromatographic software.
(h) HPLC Column-250 mm x 4.6 mm id, 5 u, Zorbax Amino column from Agilent Technologies, Part No. 880952-708.
(i) Mobile Phase-10% of 0.1% (v/v) triethylamine in water, pH adjusted to 4.0 with Phosphoric Acid; 90 % Acetonitrile
HPLC Conditions
Mobile Phase: 10:90 buffer(describe above):Acetonitrile isocratic at 2.0 mL/min
UV Wavelength: 240 nm
Column Temperature: 25°C
Injection Volume: 20uL
Retention Time of Allantoin: 6.2 minutes
Run Time: 10 minutes
Sample Analysis
Using the method of external calibration, peak area vs. concentration was plotted for each standard, which was run in duplicate. A calibration curve was then constructed.
Calibration
To calculate the % Allantoin in a sample, the following calculation was used:
% Allantoin in sample= ug/mL Allantoin (read from calibration curve) x 50 mL/ weight of sample in g (1g/1x 106 ug) x 100%
For example: % Allantoin in sample= 57.90 ug/mL Allantoin (read from calibration curve) x 50 mL/ 0.6082 g (1g/1x 106 ug) x 100% = 0.476%