Inhibitory effect of sixteen pharmaceutical excipients on six major organic cation and anion uptake transporters

Effects of Commonly used Surfactants, Poloxamer 188 and Tween 80, on the Drug Transport Capacity of Intestinal Glucose Transporters

Some glycoside drugs can be transported through intestinal glucose transporters (IGTs). The surfactants used in oral drug preparations can affect the function of transporter proteins. This study aimed to investigate the effect of commonly used surfactants, Poloxamer 188 and Tween 80, on the drug transport capacity of IGTs. Previous studies have shown that gastrodin is the optimal drug substrate for IGTs. Gastrodin was used as a probe drug to evaluate the effect of these two surfactants on intestinal absorption in SD rats through pharmacokinetic and in situ single-pass intestinal perfusion. Then, the effects of the two surfactants on the expression of glucose transporters and tight-junction proteins were examined using RT-PCR and western blotting. Additionally, the effect of surfactants on intestinal permeability was evaluated through hematoxylin-eosin staining. The results found that all experimental for Poloxamer 188 (0.5%, 2.0% and 8.0%) and Tween 80 (0.1% and 2.0%) were not significantly different from those of the blank group. However, the AUC(0-∞) of gastrodin increased by approximately 32% when 0.5% Tween 80 was used. The changes in IGT expression correlated with the intestinal absorption of gastrodin. A significant increase in the expression of IGTs was observed at 0.5% Tween 80. In conclusion, Poloxamer 188 had minimal effect on the drug transport capacity of IGTs within the recommended limits of use. However, the expression of IGTs increased in response to 0.5% Tween 80, which significantly enhanced the drug transport capacity of IGTs. However, 0.1% and 2.0% Tween 80 had no significant effect.

Development of fexofenadine self-microemulsifying delivery systems: an efficient way to improve intestinal permeability

Aim: The present study aimed to prepare and evaluate fexofenadine self-microemulsifying drug-delivery systems (SMEDDS) formulation and to determine and compare its intestinal permeability using in situ single-pass intestinal perfusion (SPIP) technique. Methods: Fexofenadine-loaded SMEDDS were prepared and optimized. Droplet size, polydispersity index, zeta potential, drug release and intestinal permeability were evaluated. Results: Optimized formulation consisted of 15% oil, 80% surfactant and 5% cosolvent. Droplet size and drug loading of optimized formulation was 13.77 nm and 60 mg/g and it has released 90% of its drug content. Intestinal permeability of fexofenadine was threefold enhanced in SMEDDS compared with free fexofenadine. Conclusion: The results of our study revealed that SMEDDS could be a promising tool for oral delivery of fexofenadine with enhanced dissolution rate and intestinal permeability.

Potential Involvement of Organic Anion Transporters in Drug Interactions with Shuganning Injection, a Traditional Chinese Patent Medicine

Traditional Chinese medicine injections have been widely used in China for the treatment of various diseases. Transporter-mediated drug-drug interactions are a major contributor to adverse drug reactions. However, the research on transporter-mediated Traditional Chinese medicine injection-drug interactions is limited. Shuganning injection is a widely used Traditional Chinese medicine injection for treating various liver diseases. In this study, we investigated the inhibitory effect of Shuganning injection and its four main ingredients (baicalin, geniposide, chlorogenic acid, and oroxylin A) on 9 drug transporters. Shuganning injection strongly inhibited organic anion transporter 1 and organic anion transporter 3 with IC50 values < 0.1% (v/v), and moderately inhibited organic anion transporter 2, organic anion transporting-polypeptide 1B1, and organic anion transporting-polypeptide 1B3 with IC50 values < 1.0%. Baicalin, the most abundant bioactive ingredient in the Shuganning injection, was identified as both an inhibitor and substrate of organic anion transporter 1, organic anion transporter 3, and organic anion transporting-polypeptide 1B3. Oroxylin A had the potential to act as both an inhibitor and substrate of organic anion transporting-polypeptide 1B1 and organic anion transporting-polypeptide 1B3. In contrast, geniposide and chlorogenic acid had no significant inhibitory effect on drug transporters. Notably, Shuganning injection markedly altered the pharmacokinetics of furosemide and atorvastatin in rats. Using Shuganning injection as an example, our findings support the implementation of transporter-mediated Traditional Chinese medicine injection-drug interactions in the development of Traditional Chinese medicine injection standards.

Wedelolactone protects against cisplatin-induced nephrotoxicity in mice via inhibition of organic cation transporter 2

The balance of cisplatin uptake and efflux, mediated mainly by organic cation transporter 2 (OCT2) and multidrug and toxin extrusion 1 (MATE1), respectively, determines the renal accumulation and nephrotoxicity of cisplatin. Using transporter-mediated cellular uptake assay, we identified wedelolactone (WEL), a medicinal plant-derived natural compound, is a competitive inhibitor of OCT2 and a noncompetitive inhibitor of MATE1. Wedelolactone showed a selectivity to inhibit OCT2 rather than MATE1. Cytotoxicity studies revealed that wedelolactone alleviated cisplatin-induced cytotoxicity in OCT2-overexpressing HEK293 cells, whereas it did not alter the cytotoxicity of cisplatin in various cancer cell lines. Additionally, wedelolactone altered cisplatin pharmacokinetics, reduced kidney accumulation of cisplatin, and ameliorated cisplatin-induced acute kidney injury in the Institute of Cancer Research mice. In conclusion, these findings suggest a translational potential of WEL as a natural therapy for preventing cisplatin-induced nephrotoxicity and highlight the need for drug-drug interaction investigations of WEL with other treatments which are substrates of OCT2 and/or MATE1.

Abdulbaqi I, Seok Ming T, Siok Yee C, A. Wahab H, Asif SM, Darwis Y. Liquid and Solid Self-Emulsifying Drug Delivery Systems (SEDDs) as Carriers for the Oral Delivery of Azithromycin: Optimization, In Vitro Characterization and Stability Assessment

Azithromycin (AZM) is a macrolide antibiotic used for the treatment of various bacterial infections. The drug is known to have low oral bioavailability (37%) which may be attributed to its relatively high molecular weight, low solubility, dissolution rate, and incomplete intestinal absorption. To overcome these drawbacks, liquid (L) and solid (S) self-emulsifying drug delivery systems (SEDDs) of AZM were developed and optimized. Eight different pseudo-ternary diagrams were constructed based on the drug solubility and the emulsification studies in various SEDDs excipients at different surfactant to co-surfactant (Smix) ratios. Droplet size (DS) < 150 nm, dispersity (Đ) ≤ 0.7, and transmittance (T)% > 85 in three diluents of distilled water (DW), 0.1 mM HCl, and simulated intestinal fluids (SIF) were considered as the selection criteria. The final formulations of L-SEDDs (L-F1(H)), and S-SEDDs (S-F1(H)) were able to meet the selection requirements. Both formulations were proven to be cytocompatible and able to open up the cellular epithelial tight junctions (TJ). The drug dissolution studies showed that after 5 min > 90% and 52.22% of the AZM was released from liquid and solid SEDDs formulations in DW, respectively, compared to 11.27% of the pure AZM, suggesting the developed SEDDs may enhance the oral delivery of the drug. The formulations were stable at refrigerator storage conditions.