ABSTRACT
Background and Objectives:Parabens are one of the chemicals used widely in preserving foods and pharmaceutical preparations. Although it was safe for many years, recently it has been proven that its action mimics estrogen in the body when it is linked to its receptors, known as estrogen receptors which are present in many systems of the body and that it may have a link with breast cancer, especially after it was found in samples of breast cancer. As known that estrogen receptors are placed in different areas in the body, including the stomach, therefore it may have a role in cancer formation and development in the stomach.The purpose of this manuscript is to investigate the presence of Methyl, Ethyland Propylparaben in stomach cancer in men and women.Methods:Samples of stomach cancer have been collected immediately after surgery in Al Assad University Hospital and after extracting parabens from samples, they have been analyzed by HPLC / MS in the science faculty at Damascus University.Results:All samples have the three types ofparabens with total mean concentration (22.5 ± 0.4 ng/g).The concentration of Methylparaben was the highest (8.2 ± 0.3 ng/g) then Propylparaben (7.4 ± 0.4 ng/g) and finally Ethylparaben (6.9 ± 0.2 ng/g).Conclusion: Because of the presence of parabens inall stomach cancer samples, so more studies must be done to research if parabens may have any effect in the formation of abnormal cells and the formation of cancer in the body systems which have estrogen receptor
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Objective: To develop an HPLC method for simultaneous determination of pregabalin, methylparaben and propylparaben in pregabalin oral solution. Methods: The analytical column was the CPACELL PAK C18 column(250 mm×4.6 mm, 5 μm). The mobile phase A was 25 mmol/L potassium dihydrogen phosphate solution(previously adjusted to pH 6.7 with concentrated ammonia)and the mobile phase B was methanol. Gradient elution was carried out at a flow rate of 1.0 ml/min. The detection wavelength was set at 210 nm for all analytes. The column temperature was maintained at 30℃, and the injection volume was 20 μl. Results: The linear ranges for pregabalin, methylparaben, propylparaben were 1000.45-4001.78, 65.21-260.84, and 8.17-32.68 μg/ml(all r≥0.9995), respectively. Their average recoveries were 100.17%(RSD=1.06%), 100.30%(RSD=0.56%), and 99.92%(RSD=0.28%)(n=9), respectively. Conclusion: The established HPLC method is simply operable, efficient, accurate and reproducible, which could be used for the quantitative determination of pregabalin and paraben preservatives in pregabalin oral solution.
ABSTRACT
OBJECTIVE: To establish an HPLC method for determination of the preservatives in betamethasone injectable suspension, including benzyl alcohol, methylparaben and propylparaben. METHODS: The determination method was developed with 5 mmol·L-1 ammonium acetate(containing 1% triethylamine and adjusted to pH 5.0 with glacial acetic acid) as mobile phase A and acetonitrile as mobile phase B, and gradient elution was performed at a flow rate of 1.0 mL·min-1. The column temperature was maintained at 30℃ and the detection wavelength was set at 257 nm. RESULTS: The resolutions between the three main peaks and adjacent peaks were greater than 1.5. The calibration curves of benzyl alcohol, methylparaben and propylparaben showed good linearity in the ranges of 0.175 9-1.758 6 mg·mL-1(r=1.000 0), 0.022 3-0.223 1 mg·mL-1(r=0.999 8), 0.004 35-0.043 47 mg·mL-1(r=1.000 0), respectively. The average recovery rates were 98.98%, 99.38% and 100.07%, and the RSDs were 0.6%, 1.3% and 1.0%(n=9), respectively. The results of test of influencing factors showed that the contents of hydroxyphenylmethyl ester and propylparaben decreased at high temperature. CONCLUSION: The developed method is proved by validation to be applicable for the quality control of the preservatives in betamethasone injectable suspension.