Search

Fungal keratitis is one of the major causes in loss of vision and blindness. Amphotericin B (AmB) is the first-line treatment of keratitis caused by Candida spp. and related fungi. Due to its high molecular weight and low aqueous solubility, it hampers the ocular bioavailability. It is well-known that γ-cyclodextrin (γCD) can enhance AmB solubility. The aim of this study was to investigate the effect of the additives on γCD solubilization of AmB and develop AmB eye drop nanosuspensions. 0.18% (w/v) AmB nanosuspensions containing either 0.25% (w/v) chitosan or 0.10% (w/v) phospholipids (PL) in aqueous γCD eye drop medium were prepared by using high pressure homogenization technique. Physicochemical properties, in vitro mucoadhesive, in vitro permeation, degree of AmB aggregation, hemolytic activity and in vitro antifungal test were determined. The physicochemical properties of the nanosuspensions containing AmB/γCD nanoaggregates were in the acceptable range. The particle size of all formulations was in nanometer range. The degree of aggregation was less than 2.0 that meant the drug was not in the aggregate form when solubilized in γCD. These formulations demonstrated relatively low hemolytic activity and effectively improved the antifungal activity. AmB/γCD nanosuspension stabilized by 0.10% (w/v) PL is the promising formulation for further studies due to that it was excellent physical appearance, had mucoadhesive property, enhanced in vitro permeation, had low toxicity and improved the antifungal activity.

The poor aqueous solubility of irbesartan (IRB) and candesartan cilexetil (CAC) may hamper their bioavailability when orally or topically administered. Among several attempts, the promising nanoaggregate formation by γ-cyclodextrin (γCD) complexation of drugs in aqueous solution with or without water-soluble polymers was investigated. According to phase solubility studies, Soluplus® showed the highest complexation efficiency (CE) of drug/γCD complexes among the polymers tested. The aqueous solubility of IRB and CAC was markedly increased as a function of Soluplus

Voriconazole (VCZ) is a broad-spectrum antifungal agent used to treat ocular fungal keratitis. However, VCZ has low aqueous solubility and chemical instability in aqueous solutions. This study aimed to develop VCZ eye drop formulations using cyclodextrin (CD) and water-soluble polymers, forming CD complex aggregates to improve the aqueous solubility and chemical stability of VCZ. The VCZ solubility was greatly enhanced using sulfobutyl ether β-cyclodextrin (SBEβCD). The addition of polyvinyl alcohol (PVA) showed a synergistic effect on VCZ/SBEβCD solubilization and a stabilization effect on the VCZ/SBEβCD complex. The formation of binary VCZ/SBEβCD and ternary VCZ/SBEβCD/PVA complexes was confirmed by spectroscopic techniques and in silico studies. The 0.5% w/v VCZ eye drop formulations were developed consisting of 6% w/v SBEβCD and different types and concentrations of PVA. The VCZ/SBEβCD systems containing high-molecular-weight PVA prepared under freeze–thaw conditions (PVA-H hydrogel) provided high mucoadhesion, sustained release, good ex vivo permeability through the porcine cornea and no sign of irritation. Additionally, PVA-H hydrogel was effective against the filamentous fungi tested. The stability study revealed that our VCZ eye drops provide a shelf-life of more than 2.5 years at room temperature, while a shelf-life of only 3.5 months was observed for the extemporaneous Vfend® eye drops.

Asiaticoside (AS), an active herbal compound isolated from Centella asiatica, has the potential benefit in promoting type I collagen (COL I) synthesis and osteogenic differentiation in human periodontal ligament cells (HPDLCs). However, it has low aqueous solubility which may hamper the bioavailability. Thus, the aim of this study was to develop thermoresponsive in situ gel containing AS/cyclodextrin (CD) complexes. The non-encapsulated formulations consisted of AS/hydroxypropyl β-CD (HPβCD) complexes and encapsulated formulations containing AS loaded sulfobutylether β-CD/chitosan nanoparticles (SBEβCD/CS NPs) were prepared. The appearance, pH and viscosity of all formulations were within the acceptable range. All formulations formed relatively rapid sol-to-gel transition when contacted with simulated salivary fluid at body temperature. Compared to non-encapsulated formulations, in vitro gelation and rheological studies of encapsulated formulations displayed gel formation that remained longer with high mechanical strength. In vitro mucoadhesion and in vitro release studies revealed that nanoencapsulated in situ gel had excellent mucoadhesive property and could release AS in a sustained manner. These formulations exhibited no cytotoxic effects to HPDCLs. The SBEβCD/CS NPs containing low AS content could express the COL I synthesis. Thus, nanoencapsulated platform could serve as a promising carrier to deliver AS for periodontal tissue regeneration.