Niosomes for oral delivery of nateglinide:in situ–in vivocorrelation

Abstract

Niosomes have been claimed to enhance intestinal absorption and to widen the absorption window of acidic drugs. This was reported after monitoring the intestinal absorption in situ. Accordingly, the aim of this work was to investigate the effect of niosomal encapsulation on intestinal absorption and oral bioavailability of nateglinide. This was conducted with the goal of correlation between in situ intestinal absorption and in vivo availability. The drug was encapsulated into proniosomes. The niosomes resulting after hydration of proniosomes were characterized with respect to vesicle size and drug entrapment efficiency. The in situ rabbit intestinal absorption of nateglinide was monitored from its aqueous solution and niosomes. Streptozotocin was used to induce diabetes in albino rats which were then used to assess the hypoglycemic effect of nateglinide after oral administration of aqueous dispersion and niosomal systems. The prepared vesicles were in the nanoscale with the recorded size being 283 nm. The entrapment efficiency depended on the pH of the formulation. The in situ intestinal absorption reflected non-significant alteration in the membrane transport parameters of the drug after niosomal encapsulation compared with the free drug solution. In contrast, niosomes showed significant improvement in the rate and extent of the hypoglycemic effect compared with the unprocessed drug. This discrepancy can be attributed to different transport pathway for the drug after niosomal inclusion with the vesicles undergoing translymphatic transport which can minimize presystemic metabolism. However, this requires confirmatory investigations. In conclusion niosomes can enhance oral bioavailability of nateglinide with the absorption being through nontraditional pathway.

Role of nanostructures in improvising oral medicine

“…Glimepiride and nateglinide loaded niosomes have been reported to increase the oral bioavailability in comparison to the free drug [39,40]. Oral administration of Telmisartan loaded niosomes have been found to significantly reduce the blood pressure in methyl prednisolone acetate mediated hypertensive Wistar rat models and also attenuates the expression level of angiotensin II receptor type 1 (AT1R) gene [41].…”

An Experimental Study on the Effect of Pyrimethamine-Loaded Niosomes in the Treatment of Acute Toxoplasmosis

“…This material can fluidize the intestinal membrane with subsequent enhancement of bioavailability of the drug. The vesicular structure of niosomes was also linked with preferential lymphatic transport avoiding the pre-systemic metabolism and increased bioavailability (Sultan et al, 2016(Sultan et al, , 2018Zoghroban et al, 2019). The ability of niosomes to fuse to the surface of the organisms as bacteria leading to entry of high concentrations of the carried drug into the organism has been suggested by Abdelaziz et al, (2015) and this may occur also in Toxolasma tachyzoites.…”

“…The properties can be further modified by manipulating the composition of niosomes. Peceol, a membrane fluidizing material has been added to niosomes to improve the oral bioavailability with the recorded positive results being explained on the base of enhanced membrane permeability and/or preferential lymphatic transport (Sultan et al, 2016(Sultan et al, , 2018Zoghroban et al, 2019). These vesicles have been shown to enhance the bioavailability of many drugs with promising data being recorded against parasites like Shistosoma in vitro and in vivo (Zoghroban et al, 2019).…”

Development, characterization and in vitro–in vivo evaluation of Farnesol loaded niosomal gel for applications in oral candidiasis treatment

“…An overlay was also taken to investigate FAR presence in niosomes. For the DSC analysis, 2 mg of dried samples of niosomes were selected and for the measurement, a 50 C-450 C temperature range along with a 20 ml/ min N2 flow rate and a constant heating rate of 20 C were employed [25,26].…”