Novel pH-sensitive non-ionic surfactant vesicles: comparison between Tween 21 and Tween 20

Area of Science:

• Pharmaceutical Technology
• Nanotechnology
• Drug Delivery Systems

Background:

• Vesicular drug delivery systems like liposomes and niosomes offer advantages over conventional forms.
• Niosomes are gaining attention as a viable alternative to liposomes for drug delivery.
• Polysorbate 21 (Tween 21) was investigated for its potential in forming niosomal formulations.

Purpose of the Study:

• Determine the critical micelle concentration (CMC) of polysorbate 21.
• Analyze the capability of polysorbate 21 to form niosomal formulations.
• Characterize the properties of Tween 21-based niosomes for drug delivery applications.

Main Methods:

• Niosomal formulations were prepared using Tween 21 and cholesterol (CHOL) at an equimolar ratio via the film technique.
• Dynamic light scattering (DLS) was employed to assess vesicle size, zeta potential, polydispersity index, and colloidal stability.
• Microviscosity and pH-sensitivity were evaluated using fluorescent probes.

Main Results:

• Tween 21 and cholesterol formed homogenous, monodisperse niosomes with sizes around 100nm, suitable for crossing biological barriers.
• The niosomal formulation exhibited good stability for at least 90 days at 4°C.
• The prepared vesicles demonstrated pH-sensitivity.

Conclusions:

• Tween 21 is capable of forming stable niosomal drug delivery systems.
• These niosomes possess characteristics, including pH-sensitivity and appropriate size, for targeted drug delivery.
• The formulation holds potential as pH-sensitive nanodevices for delivering drugs to acidic pathological tissues.