Volume 9(6): 528-529 (2017) - 528
J Bioequiv Availab, an open access journal
ISSN: 0975-0851
Open Access
Kulsirirat et al., J Bioequiv Availab 2017, 9:6
DOI: 10.4172/jbb.1000357
Research Article OMICS International
Journal of Bioequivalence & Bioavailability
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ISSN: 0975-0851
Keywords: P-glycoprotein (P-gp); Non-ionic surfactant; High-
roughput screening; Bioluminescence; Pgp-Glo™ assay; Efflux
transporters
Introduction
e number of poorly soluble and lipophilic drugs with limited
oral bioavailability among the new drug entities entering formulation
development has increased over the last years. In many cases lower oral
bioavailability entails higher inter-individual variability in bioavailability
[1]. is can result in an inadequate control of plasma concentrations and
pharmacological effects. Besides solubility and gastric stability, metabolic
processes as well as transporter-mediated efflux play an essential role in
influencing oral bioavailability of drugs [2]. P-glycoprotein (P-gp), also
known as MDR1 and ABCB1, is a 170 kDa integral plasma membrane
protein that functions as an ATP-dependent drug efflux pump and plays
an essential role in multi-drug resistance and certain adverse drug-drug
interactions [3]. Its efflux mechanism involves the protein binding to
the ATP and requires energy derived by the hydrolysis of ATP to ADP
in the presence of adenosine-triphosphatase enzyme (ATPase) [4].
P-gp belongs to the ATP-binding cassette (ABC) transporter subfamily
that combines a wide range of proteins found in a number of different
species. ABC transport proteins mediate the transport of a diversity of
structurally different substances like amino acids, ions, peptides and
also a variety of drugs through cell membranes [4]. A common method
to improve the oral bioavailability of drugs is the use of solubilizing
agents like complex forming hydroxypropyl β cyclodextrin, co-solvents
or surfactants in drug formulations. However, the knowledge about
interactions between nonionic surfactants and the efflux transporter
P-gp is limited up to date. In this study, to investigated whether non-
ionic surfactant stimulated or inhibited the ATPase activity of P-gp
using Pgp-Glo
TM
assay systems.
Methods
Preparation of buffers and solutions
e Pgp-Glo™ assay systems contain the necessary reagents for
performing luminescent P-glycoprotein (P-gp) ATPase assays. e ATP
detection buffer was thawed and equilibrated to room temperature. en
the ATP detection buffer was shaken briefly to resuspend any precipitate
The Potential of Non-Ionic Surfactant Against P-Glycoprotein Efflux
Transporters for Drug Development System
Kulsirirat T
1
, Rukthong P
2
, Dechwongya P
1
and Sathirakul K
1,3*
1
Faculty of Pharmacy, Mahidol University, Bangkok, Thailand
2
Faculty of Pharmacy, Srinakharinwirot University, Nakhon-Nayok, Thailand
3
Drug Discovery and Development Center, Thammasart University (Rangsit campus), Pathum Thani, Thailand
Abstract
Polysorbates (Tweens) are widely used in pharmaceutical formulations as excipients, such as stabilizer or
solubilizer, for poorly soluble drugs. The efflux transporters ABCB1 (P-glycoprotein, P-gp) play an essential role
in limiting the oral bioavailability of drugs. P-gp is expressed in the intestinal epithelium, thereby, it significantly
impairs the systemic absorption of various active substances. The present study is to investigate a new property of
polysorbates including its ability to stimulate or inhibit the efflux transporter P-glycoprotein (P-gp) using Pgp-Glo™
assay systems. The Pgp-Glo
TM
assay systems are luminescent P-glycoprotein (P-gp) ATPase assays. It detected
the effect of substance on recombinant human P-gp in a cell membrane fraction. The investigation showed that the
concentration of 0.1% Tween 80 is an inhibitor of P-gp ATPase activity, whereas, the concentrations of 0.5% and 1%
of Tween 80 demonstrated as a stimulator. All of these concentrations of Tween 20 were observed to be an inhibitory
effect on P-gp ATPase activity.
that may form aſter freezing. en the entire content of the bottle of
ATP detection buffer was transferred to the amber bottle containing
the lyophilized ATP detection substrate and swirled or inverted several
times to obtain a homogeneous solution of ATP detection reagent.
Finally, 2.5 fold of concentration of test compounds in Pgp-Glo™ assay
buffer were prepared.
Preperation of P-gp membranes
e Pgp-Glo™ assay system detects the effects of compounds
on recombinant human P-gp in a cell membrane fraction. e P-gp
membranes were prepared rapidly at 37
°
C and were immediately kept
on ice until they became ready to use. Unused P-gp membranes were
dispensed into single-use aliquots and stored at -70
°
C. en 5 mg/ml
membranes were diluted to 1.25 mg/ml with Pgp-Glo™ assay buffer.
Performing the assay
e Pgp-Glo™ assay systems were used to analyze the effects of
polysorbates (Tweens) on the activity of P-gp. Preperations of P-gp
reaction mixtures and ATP reagent were done as described above. 20
μl of polysorbates were prepared in different concentrations (0.1, 0.5
and 1% v/v), Verapamil (positive control as P-gp substrate, 0.5 mM)
and sodium orthovanadate (P-gp inhibitor, 0.25 mM) were added into a
white opaque 96-well plate. P-gp was then added into the well containing
the test substances and then this well were incubated at 37°C for 40 min.
e reactions were stopped and luminescence was initiated by adding
*Corresponding author: Sathirakul K, Drug Discovery and Development
center, Thammasart University (Rangsit campus), Pathum Thani, Thailand, Tel:
+66863208895; E-mail: pyksk2001@yahoo.com.sg
Received May 17, 2017; Accepted September 27, 2017; Published October 05,
2017
Citation: Kulsirirat T, Rukthong P, Dechwongya P, Sathirakul K (2017) The Potential
of Non-Ionic Surfactant Against P-Glycoprotein Efflux Transporters for Drug
Development System. J Bioequiv Availab 9: 528-529. doi: 10.4172/jbb.1000357
Copyright: © 2017 Kulsirirat T, et al. This is an open-access article distributed
under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original
author and source are credited.