Abstract

SPANLASTICS AS VERSATILE ELASTIC NANOCARRIERS: ADVANCES IN DESIGN, CHARACTERIZATION, AND DRUG DELIVERY APPLICATIONS

Sayan Das*, Pritam Kundu, Subhashini B. Hawaldar and Anju K. P.

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Abstract

Spanlastics are a novel and adaptable class of elastic nanocarriers that have gained considerable attention in the field of drug delivery. They are made using non-ionic surfactants such as Span and edge activators like Tween. These vesicles are designed to be flexible enough to cross biological membranes, enhancing drug absorption and therapeutic effectiveness. They can be formulated through several methods including thin-film hydration, ethanol injection, and sonication, with each method influencing the final properties of the vesicles. To ensure their quality and performance, spanlastics undergo a variety of characterization tests. The vesicle size and polydispersity index (PDI) help assess the uniformity and distribution of the particles. Zeta potential is measured to evaluate the surface charge, which plays a key role in predicting stability during storage. Morphology analysis, often performed using microscopic techniques, reveals the shape and structural integrity of the vesicles. Elasticity or deformability studies are crucial, as they determine the vesicle’s ability to adapt to tight junctions and penetrate deep tissue layers. Other important parameters include drug entrapment efficiency, release behaviour, and compatibility under different pH conditions. Spanlastics have shown promising results across various delivery routes. Orally, they help improve the solubility and absorption of poorly water-soluble drugs. In ocular formulations, they increase corneal retention and drug penetration. Their flexibility makes them effective in transdermal and intranasal applications, offering enhanced bioavailability and targeted delivery. Additionally, they are being explored for gene therapy and vaccine delivery due to their safety, versatility, and ability to carry sensitive biomolecules.

Keywords: Spanlastics, Elastic nanovesicles, Novel vesicular approach, Bilayered vesicles.