Tamarind seed polysaccharide (TSP) uses in ophthalmic drug delivery

Abstract

author: matheuscastro123@hotmail.com Abstract At present, ophthalmic drug delivery remains a major challenge, given the eye's protective structure and susceptibility to irritation, resulting in poor patient adherence. In order to overcome these constraints, new formulations are continually being developed. The inclusion of Galactoxyloglucan (Tamarind seed polysaccharide (TSP) in such formulations, a natural substance extracted from the seeds of Tamarindus indica , has shown great potential due to its physicochemical properties, high biocompatibility and safety profile. Such properties, have led to its use in formulations for the treatment of dry eye disease, glaucoma, and bacterial keratitis, as well as in dilating eye drops used in eye examinations. In this article, we highlight the most recent TSP-based ophthalmologic formulations, which indicate that this polymer is a strong candidate to reduce adverse effects, improve patient tolerability and rufloxacin administration resulted in slightly higher intraocular drug levels than rufloxacin alone, as shown by the values observed in uninfected (4.62 g/ml; P 0.01), P. aeruginosa -infected (5.63 g/ml; P 0.01), and S. aureus-infected (6.91 g/ml; P 0.001) eyes. In the cornea, TSP-rufloxacin was slightly more effective than rufloxacin alone in regulating P. aeruginosa bacterial proliferation. With regard to S. aureus, TSP-rufloxacin administration resulted in a significant drop in corneal bacteria relative to both rufloxacin-treated and ofloxacin-treated eyes (P 0.05). A further study was conducted evaluating different formulations of rufloxacin (RUF) with TSP, namely two pH 7.2 suspensions of non-salified rufloxacin base, one of which was thickened with TSP; two pH 7.2 solutions of RUF obtained using hydroxypropyl- β cyclodextrin (CD), one with TSP; and two pH 5.0 solutions of rufloxacin hydrochloride (RUF-HCl), one containing TSP 33 . In this study, the suspension containing TSP showed twice the concentration in aqueous humor compared to S-RUF (187.88 vs 67.63 min µg/mL), given the viscosity potential of the polysaccharide. Additionally, pH levels were also shown to influence drug concentration, since the concentration was higher at pH 7.2 when compared to the same formulation at pH 5.0. Rufloxacin solubilization in HP- β -CD (pH 7.2) irrespective of whether or not it contained TSP, showed, poor performance in the final concentration. This could be explained by the fact that the drug interacted strongly with the cyclodextrins and that