Dear Mahmood,

The attached publications cover the answer to your question:

1-Biomed Microdevices (2009) 11:1115–1125 DOI 10.1007/s10544-009-9328-2

Novel PEG-coated niosomes based on bola-surfactant as drug carriers for 5-fluorouracil

D. Cosco & D. Paolino & R. Muzzalupo & C. Celia & R. Citraro & D. Caponio & N. Picci & M. Fresta

Abstract Innovative niosomes made up of α,ω-hexadecylbis-(1-aza-18-crown-6)

(bola), Span 80® and cholesterol (2:5:2 molar ratio) are proposed as suitable delivery systems for the administration of 5-fluorouracil (5-FU), an antitumoral compound largely used in the treatment of breast cancer. The bola-niosomes, after sonication procedure, showed mean sizes of ~200 nm and a loading capacity of ~40% with respect to the amount of 5-FU added during the preparation. Similar findings were achieved with PEG-coated bola-niosomes (bola, Span 80®, cholesterol, DSPE-mPEG2000, 2:5:2:0.1 molar ratio respectively). 5-FU-loaded PEG-coated and uncoated bolaniosomes were tested on MCF-7 and T47D cells. Both bola-niosome formulations provided an increase in the cytotoxic effect with respect to the free drug. Confocal laser scanning microscopy studies were carried out to evaluate both the extent and the time-dependent bola-niosome-cell

interaction. In vivo experiments on MCF-7 xenograft tumor SCID mice models showed a more effective antitumoral activity of the PEGylated niosomal 5-FU at a concentration ten times lower (8 mg/kg) than that of the free solution of the drug (80 mg/kg) after a treatment of 30 days.

2-In this publication, you can find the approach using variation of parameters to separate between niosomes with drug and without (see attached file).

AAPS PharmSciTech. 2010 Sep; 11(3): 1119–1127.

Published online 2010 Jul 16. doi:  10.1208/s12249-010-9480-2

PMCID: PMC2974162

Formulation and Optimization of Zidovudine Niosomes

Kandasamy Ruckmani and Veintramuthu Sankar

Author information ► Article notes ► Copyright and License information ►

This article has been cited by other articles in PMC.

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Abstract

Zidovudine (AZT) is commonly used to treat patients with AIDS, but it is limited by toxicity and high dosing needs. Alternative formulations have been proposed to overcome these drawbacks. The objective of this study was to evaluate process-related variables like hydration and sonication time, rotation speed of evaporation flask, and the effects of charge-inducing agent and centrifugation on zidovudine entrapment and release from niosomes. Formulation of zidovudine niosomes was optimized by altering the proportions of Tween, Span and cholesterol. The effect of process–related variables like hydration time, sonication time, charge-inducing agent, centrifugation and rotational speed of evaporation flask on zidovudine entrapment and release from niosomes was evaluated. The effect of changes in osmotic shock and viscosity were also evaluated. Non-sonicated niosomes were in the size range of 2-3.5 μm and sonicated niosomes formulated with Tween 80 and dicetylphosphate (DCP) had a mean diameter of 801 nm. Zidovudine niosomes formulated with Tween 80 entrapped high amounts of drug and the addition of DCP enhanced drug release for a longer time (88.72% over 12 h). The mechanism of release from Tween 80 formulation was the Fickian type and obeyed first-order release kinetics. Niosomes can be formulated by proper adjustment of process parameters to enhance zidovudine entrapment and sustainability of release. These improvements in zidovudine formulation may be useful in developing a more effective AIDS therapy.

KEY WORDS: AZT, entrapment efficacy, niosomes, process-related variables, zidovudine

Hoping this will be helpful,

Rafik

dear Rafik Karaman

thanks a lot.

After PEG coating, niosomes will show increase in size which can be detected by various means. It will be really difficult to separate them except for size based separation such as dialysis. However, you can ensure PEG coating on niosomes to avoid separation process.

Mubashar Rehman, thanks from you