Closantel nano-encapsulated polyvinyl alcohol (PVA) solutions

Abstract

The influence of closantel on the rheological and physicochemical properties (particle size and by UV-Vis absorption spectroscopy) of PVA aqueous solutions is studied here. About 1% PVA aqueous solutions were prepared by varying the closantel content. The increase of closantel content led to a reduction in the particle size of final solutions. All the solutions were buffered at pH 7.4 and exhibited shear-thinning behavior. Furthermore, in oscillatory flow, a "solid-like" type behavior was observed for the sample containing 30 μg/mL closantel. Indicating a strong interaction between the dispersed and continuous phases and evidencing an interconnected network between the nanoparticle and PVA, this sample also showed the highest shear viscosity and higher shear thinning slope, indicating a more intrincate structure disrupted by shear. In conclusion, PVA interacts with closantel in aqueous solution and the critical concentration for closantel encapsulation by PVA was about 30 μg/mL; above this concentration, the average particle size decreased notoriously which was associated to closantel interacting with the surface of the PVA aggregates and thus avoiding to some extent direct polymer-polymer interaction.

Salicylanilides and Their Anticancer Properties

“…However, there are already more recent studies reporting new formulations of niclosamide, as a development of amorphous solid dispersion [ 174 ] or reformulated niclosamide as a niclosamide stearate prodrug therapeutic [ 175 ]. Moreover, similar reformulation efforts already exist in the case of other salicylanilides such as closantel [ 171 ], rafoxanide [ 170 ] and even in the case of structurally related nitazoxanide [ 172 , 176 ].…”

“…In general, salicylanilides are weakly acidic, highly lipophilic compounds [ 17 ]. Low water solubility is typical not only for niclosamide [ 169 ], but also for other salicylanilides such as rafoxanide (whose solubility in water was reported to be less than 0.1 μg/mL) [ 170 ], closantel [ 171 ] and for nitrothiazolyl-salicylamide nitazoxanide as well [ 172 ]. As it was already mentioned, to overcome challenges connected to the undesirable physicochemical properties that influence oral bioavailability, a number of studies reported diverse innovative formulations of salicylanilides.…”

Exploring the impact of CoFe2O4 additives morphology on the properties of a novel strain-rate sensitive composite material

“…Due to the increase of the dipole interaction among the suspended magnetic additives, they can reversibly change the effective viscosity and modulus by forming a chain structure under an external magnetic field, showing a typical shear-thinning behavior [28]. Many groups have reported that the particles tend to form aggregates due to long-range attractions in system; subsequently the aggregates are disrupted under flow, resulting in a shear thinning behavior toward motion [29][30][31][32][33]. Chen et al [34] treated the MWNT with functionalized surfaces and controlled morphologies to form a silicon oil based rheological material.…”