Investigation of the impact of some Excipients on activity of P-gp based on SPIP technique in animal model of Rat

Abstract

Nowadays effective intestinal drug delivery for reasons such as; non-invasive method, easier usage by the patients, changeable timing of the drug and the ability to deliver multiple drugs simultaneously in one specific formulation is taking into consideration by many researchers. Many drugs used for treating diseases orally must be able to cross the absorption membrane and be absorbed, in order to be effective. One way to increase the intestinal absorption of drugs is to use specific excipients which has made a big difference in the treatment of many diseases. Objective: In this study we investigated and compared the effect of adding excipients such as tween 20, tween 40, PEG 400, PEG 6000 and vitamin E to digoxin to increase intestinal absorption of it. Materials and Methods: This research was experimented on an animal model of adult Wistar rats. After induction of anesthesia, the abdomen part of small intestine of rats was cannulated in and out about 10 cm. Then digoxin solution with phenol red was perfused into the intestine and sampled from the outlet canal in specified times. Finally the collected samples were analyzed by HPLC. Results: The results of this study showed that vitamin E, PEG 400, PEG 6000, tween 20, tween 40 and verapamil increased by 1.27, 1.82, 2.01, 2.92, 3.09 and 3.32 times the effective absorption compared to the state without intervention of inhibitors or excipients. Conclusion: Based on the results excipients used in pharmacy are not completely pharmacologically inactive and can have additive or decreasing effects on the bioavailabilty of drugs.