Toxicology Letters 188 (2009) 33–37 F1 陳筱惠 指導醫師：顏宗海醫師

1. Determination of total and free mono-n-butyl phthalate in human urine samplesafter medication of a di-n-butyl phthalate containing capsule Toxicology Letters 188 (2009) 33–37 F1陳筱惠 指導醫師：顏宗海醫師

2. Introduction • Phthalates: • Industrial compounds manufactured via esterification of phthalic acid (benzene-1,2-dicarboxylic acid) with an alcohol • Apply in a lot of products as plasticisers • Diethyl phthalate (DEP) and Phthalates like di-n-butyl phthalate (DnBP)  coatings in medical drugs, 9000ug per capsule V.S. 1ug/kg b.w. as food consumption in the general population (100X)

3. Some phthalates and their metabolites are developmental toxicants (endocrine disrupting compounds, EDC) in rats and mice • Hypospadias, delayed testes descent or vaginal pouch development • The main biologically active metabolite of DnBP: free MnBP  glucuronidation detoxification

4. A valid exposure assessment as basis for a risk assessment for “normal” exposure to DnBP and DiBP and high dose exposure to DnBP after medication

5. Methods • 24h interval urine: 17 samples, 3 days • Voluntary co-workers of the Bavarian Health and Food Safety Authority and their children, 7 males (including 2 children) and 10 females (including 2 children), 9~59 year-old, 21~100 kg (mean 61 kg) • 8:00am, a capsule of an herbal drug containing 3600ug of DnBP (over-the-counter herbal pharmaceutical preparation for curing colds containing eucalyptus, anise and peppermint oil) • Control: urine collected 24h before taking it

6. Spot urine: 175 samples • 115 healthy people, 37 men and 78 women, 28~58 year-old, living in the area of Munich, a 9-month time period in the years 2007 and 2008 at random times • 60 samples with unkown sex and age • Stored at −20◦C until measurements

7. All subjects in the study: • To refrain from alcoholic beverages and medicinal drugs 2 days before and throughout the experiment • Not alcohol abuser or smokers • Self-declaration of the volunteers as healthy

8. Chemicals • Analysis of urine samples • Sample preparation for total MnBP and MiBP • Quantitation of MnBP and MiBP

9. Conversion rate: 78% Results 2X 2X Free MnBP: 14~200ug, 1~11% (median 4%) of total MnBP Free MiBP: 9.8% samples, 4.5~11.1ug

11. Endocrine active 2X Daily urine amount: 1.5/2.1L

12. Discussion • Exposure assessment: • After the administration of 3600ug of DnBP within 24hr most of the applied dose was excreted with urine as MnBP • Good agreement with previously published studies • Estimation for half life of MnBP of about 6hr

13. Control  exposure: 23ug 2248ug, 100X • Conversion rate of DnBP to MnBP: 78%  69% previously • Median uptake of DnBP and DiBP: • Lower than previous data • 1.5 L urine amount: no difference between study 1 and study 2 • 2.1L: study 2 > study 1

14. Maximum levels or 95th percentile: study 2 = 5X study 1 • Spot urine at the time points around 2h after taking DnBP or DiBP • Therefor, only median or mean values should be used for a valid exposure.

15. Risk assessment: • Free MnBP: 4% of total amount of MnBP • No difference between normal and high exposure • Comparable ratio as previous report • Lower than rat model; tolerable daily intake (TDI)  10ug/kg b.w. • 20~30% of DnBP and DiBP may be transferred to other unknown metabolites.

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