A Mucoadhesive Polymer Extracted from Tamarind Seed Improves the Intraocular Penetration and Efficacy of Rufloxacin in Topical Treatment of Experimental Bacterial Keratitis

Abstract

Bacterial keratitis is a serious infectious ocular disease requiring prompt treatment to prevent frequent and severe visual disabilities. Standard treatment of bacterial keratitis includes topical administration of concentrated antibiotic solutions repeated at frequent intervals in order to reach sufficiently high drug levels in the corneal tissue to inhibit bacterial growth. However, this regimen has been associated with toxicity to the corneal epithelium and requires patient hospitalization. In the present study, a mucoadhesive polymer extracted from tamarind seeds was used for ocular delivery of 0.3% rufloxacin in the treatment of experimental Pseudomonas aeruginosa and Staphylococcus aureus keratitis in rabbits. The polysaccharide significantly increased the intra-aqueous penetration of rufloxacin in both infected and uninfected eyes. Rufloxacin delivered by the polysaccharide reduced P. aeruginosa and S. aureus in the cornea at a higher rate than that obtained by rufloxacin alone. In particular, use of the polysaccharide allowed a substantial reduction of S. aureus in the cornea to be achieved even when the time interval between drug administrations was extended. These results suggest that the tamarind seed polysaccharide prolongs the precorneal residence times of antibiotics and enhances drug accumulation in the cornea, probably by reducing the washout of topically administered drugs. The tamarind seed polysaccharide appears to be a promising candidate as a vehicle for the topical treatment of bacterial keratitis.

Citric Acid Crosslinked Carboxymethyl Cellulose-based Composite Hydrogel Films for Drug Delivery

“…TG is composed of (1→4)-β-D-glucan back-bone substituted with side chains of α-D-xylopyranose and β-D-galactopyranosyl(1→2)-α-D-xylopyranose linked (1→6) to glucose residues [20] . It has been used in the development of various drug delivery systems due to its hydrophilic and bioadhesive properties [21][22][23][24][25][26][27] . Although TG shows presence of non-sterically hindered hydroxyl groups, very few reports mentioned the use of pure TG in chemically crosslinked hydrogels [28] .…”

Tamarind Seed Polysaccharide: An Emerging Excipient for Pharmaceutical Use

“…Tamarind seed polysaccharide was also investigated for ocular delivery of rufloxacin and ofloxacin to treat bacterial keratitis experimentally induced by Pseudomonus aeruginosa and Staphylococcus aureus in rabbits. 105 The result indicated significantly increment in intra-aqueous penetration of drugs in both infected and uninfected rabbit eyes. The use of tamarind seed polysaccharide improved the prolongation of precorneal residence time and drug accumulation by these formulations.…”

“…[103][104][105][106][107] The high viscosity and mucoadhesive property of tamarind seed polysaccharide make it as a suitable excipient in various ocular formulations for increasing the residence time for various drugs on the cornea. A tamarind gum based in situ gelling ocular dosage form of pilocarpine was developed and evaluated for its miotic potential.…”

Polysaccharides as Excipients for Ocular Topical Formulations

“…These results suggested that TSP is able to prolong the precorneal residence time of the antibiotic and enhance drug accumulation in the cornea, thereby increasing the intraaqueous antibiotic penetration. (Ghelardi et al, 2004).…”