Effects of Commonly Used Excipients on the Expression of CYP3A4 in Colon and Liver Cells
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The objective of this investigation was to assess whether common pharmaceutical excipients regulate the expression of drug-metabolizing enzymes in human colon and liver cells.
Nineteen commonly used excipients were evaluated using a panel of experiments including cell-based human PXR activation assays, real-time RT-PCR assays for CYP3A4 mRNA expression, and immunoblot analysis of CYP3A4 protein expression in immortalized human liver cells (HepG2 and Fa2N4), human primary hepatocytes, and the intestinal LS174T cell models.
No excipient activated human PXR or practically induced CYP3A4. However, three excipients (polysorbate 80, pregelatinized starch, and hydroxypropyl methylcellulose) tended to decrease mRNA and protein expression across experimental models.
This study represents the first investigation of the potential role of excipients in the expression of drug-metabolizing enzymes. Findings imply that some excipients may hold potential for excipient-drug interactions by repression of CYP3A4 expression.
KEY WORDSexcipients CYP3A4 PXR induction repression
cytochrome P450 3A4
dicalcium phosphate dehydrate
polyethylene glycol 3350
pregnane X receptor
amorphous fumed silicon dioxide
sodium lauryl sulfate
sodium starch glycolate
The authors thank Dr. Steve Kliewer (University of Texas, Southwestern Medical Center, Dallas, TX) for providing the pSG5-hPXR expression vector. Human liver tissues were procured with the assistance of Jennifer Fuhrman from the University of Maryland Medical Center (Baltimore, MD). This research was partly supported by National Institute of Health Grant (R01, DK061652).
- 1.FDA. Waiver of in vivo bioavailability and bioequivalence studies for immediate-release solid oral dosage forms based on a biopharmaceutics classification system. CDER, Guidance for Industry. 2000.Google Scholar
- 2.EMEA. Note for guidance on the investigation of bioavailability and bioequivalence. Committee for Proprietary Medicinal Products. 2001.Google Scholar
- 7.EMEA. Guideline on the investigation of bioequivalence. Committee for Medicinal Products for Human Use. 2008.Google Scholar
- 21.LeCluyse EL, Alexandre E, Hamilton GA, Viollon-Abadie C, Coon DJ, Jolley S, et al. Isolation and culture of primary human hepatocytes. Methods Mol Biol (Clifton, NJ). 2005;290:207–29.Google Scholar
- 25.Li L, Stanton JD, Tolson AH, Luo Y, Wang H. Bioactive terpenoids and flavonoids from Ginkgo biloba extract induce the expression of hepatic drug-metabolizing enzymes through pregnane X receptor, constitutive androstane receptor, and aryl hydrocarbon receptor-mediated pathways. Pharm Res. 2009;26:872–82.CrossRefPubMedGoogle Scholar
- 27.Shangraw RF. Emerging trends in the use of pharmaceutical excipients. Pharm Technol. 1997;21:36–42.Google Scholar
- 30.Yamagata T, Kusuhara H, Morishita M, Takayama K, Benameur H, Sugiyama Y. Improvement of the oral drug absorption of topotecan through the inhibition of intestinal xenobiotic efflux transporter, breast cancer resistance protein, by excipients. Drug Metab Dispos. 2007;35:1142–8.CrossRefPubMedGoogle Scholar
- 33.FDA. In vitro evaluation of CYP induction. FDA Guidelines. 2006.Google Scholar
- 34.Burk O, Koch I, Raucy J, Hustert E, Eichelbaum M, Brockmoller J, et al. The induction of cytochrome P450 3A5 (CYP3A5) in the human liver and intestine is mediated by the xenobiotic sensors pregnane X receptor (PXR) and constitutively activated receptor (CAR). J Biol Chem. 2004;279:38379–85.CrossRefPubMedGoogle Scholar
- 36.Rane Y, Mashru R, Sankalia M, Sankalia J. Effect of hydrophilic swellable polymers on dissolution enhancement of carbamazepine solid dispersions studied using response surface methodology. AAPS PharmSciTech. 8:Article 27. 2007.Google Scholar