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Abstract Background Brinzolamide (BRI) suspensions are used for the treatment of glaucoma; however, sufficient drug delivery to the target tissue after eye drop administration is hampered by poor solubility. To address this issue, we focused on nanocrystal technology, which is expected to improve the bioavailability of poor-solubility drugs, and investigated the effect of BRI nanocrystal formulations on corneal permeability and intraocular pressure (IOP)-reducing effect. Methods BRI nanocrystal formulations were prepared by the wet-milling method with beads and additives. The particle size was measured by NANOSIGHT LM10, and the morphology was determined using a scanning probe microscope (SPM-9700) and a scanning electron microscope (SEM). Corneal permeability was evaluated in vitro using a Franz diffusion cell with rat corneas and in vivo using rabbits, and the IOP-reducing effect was investigated using a rabbit hypertensive model. Results The particle size range for prepared BRI nanocrystal formulation was from 50 to 300 nm and the mean particle size was 135 ± 4 nm. The morphology was crystalline, and the nanoparticles were uniformly dispersed. In the corneal permeability study, BRI nanocrystallization exhibited higher corneal permeability than non-milled formulations. This result may be attributed to the increased solubility of BRI by nanocrystallization and the induction of energy-dependent endocytosis by the attachment of BRI nanoparticles to the cell membrane. Furthermore, the addition of tyloxapol to BRI nanocrystal formulation further improved the intraocular penetration of BRI and showed a stronger IOP-reducing effect than the commercial product. Conclusions The combination of BRI nanocrystallization and tyloxapol is expected to be highly effective in glaucoma treatment and a useful tool for new ophthalmic drug delivery.

Background: Brinzolamide (BRI) suspensions are used for the treatment of glaucoma; however, sufficient drug delivery to the target tissue after eye drop administration is hampered by poor solubility. To address this issue, we focused on nanocrystal technology, which is expected to improve the bioavailability of poor-solubility drugs, and investigated the effect of BRI nanocrystal formulations on corneal permeability and intraocular pressure (IOP)-reducing effect. Methods: BRI nanocrystal formulations were prepared by the wet-milling method with beads and additives. The particle size was measured by NANOSIGHT LM10, and the morphology was determined using a scanning probe microscope (SPM-9700) and a scanning electron microscope (SEM). Corneal permeability was evaluated in vitro using a Franz diffusion cell with rat corneas and in vivo using rabbits, and the IOP-reducing effect was investigated using a rabbit hypertensive model. Results: The particle size range for prepared BRI nanocrystal formulation was from 50 to 300 nm and the mean particle size was 135 ± 4 nm. The morphology was crystalline, and the nanoparticles were uniformly dispersed. In the corneal permeability study, BRI nanocrystallization exhibited higher corneal permeability than non-milled formulations. This result may be attributed to the increased solubility of BRI by nanocrystallization and the induction of energy-dependent endocytosis by the attachment of BRI nanoparticles to the cell membrane. Furthermore, the addition of tyloxapol to BRI nanocrystal formulation further improved the intraocular penetration of BRI and showed a stronger IOP-reducing effect than the commercial product. Conclusions: The combination of BRI nanocrystallization and tyloxapol is expected to be highly effective in glaucoma treatment and a useful tool for new ophthalmic drug delivery. [ABSTRACT FROM AUTHOR]

A nanocrystal formulation of lutein (NC/LT) was prepared by particle size reduction approach with a bottom-up system to improve nutraceutical properties of LT, and physicochemical and pharmacokinetic characterizations of NC/LT were undertaken. In NC/LT, LT nanoparticles with a mean diameter of 230 nm existed in a crystalline state, and, in comparison with crystalline LT, NC/LT exhibited a marked improvement in dissolution/dispersion behavior of LT in water. Orally-administered NC/LT exhibited enhanced oral absorption of LT in male Sprague-Dawley rats, as evidenced by relative bioavailability of 15.2 to crystalline LT. After oral administration of LT samples (100 mg-LT/kg, 7 days) to male Sprague-Dawley rats, the ocular accumulation of LT in NC/LT was 3.4-fold higher than that in crystalline LT. Upon these findings, particle size reduction of LT would be efficacious to improve its dissolution and pharmacokinetic characteristics, and NC/LT may be an attractive dosage form to enhance the nutraceutical properties of LT.

DRL‐17822 is a novel selective cholesteryl ester transfer protein inhibitor that showed an increased exposure, including an increase of >20‐fold of maximum concentration and area under the plasma concentration–time curve from time zero to the time of the last quantifiable concentration, following a high‐fat breakfast using a nanocrystal formulation. To reduce this effect of food, we generated an amorphous solid dispersion formulation. In this study, we compared the food effect of both formulations of DRL‐17822 in a 2‐part randomized, open‐label, 4‐way crossover study involving healthy adult males 18‐45 years of age. In both parts of the study, 12 subjects received both formulations of DRL‐17822 in both the fasted and fed states; a low‐fat breakfast was provided in the first part and a high‐fat breakfast in the second part. Compared to the nanocrystal formulation, the amorphous solid dispersion formulation substantially increased DRL‐17822 exposure in the fasted state, including increased maximum concentration, area under the plasma concentration–time curve from time zero to the time of the last quantifiable concentration, and area under plasma concentration–time curve from time zero to infinity. Following a high‐fat breakfast, DRL‐17822 exposure was increased to a lesser extent in the amorphous solid dispersion formulation compared to the nanocrystal formulation (P <.001). Moreover, compared to the nanocrystal formulation the amorphous solid dispersion formulation caused a more pronounced increase in high‐density lipoprotein in the fasted state. Consuming breakfast increased the effect of DRL‐17822 on high‐density lipoprotein. Taken together, our results indicate that by improving its formulation, DRL‐17822 has a favorable exposure profile and therefore a more predictable food effect profile. [ABSTRACT FROM AUTHOR]

• A nanocrystal formulation of lutein (NC/LT) was prepared using a bottom-up system. • The dissolution behavior of NC/LT was higher than that of crystalline LT in water. • Orally-taken NC/LT showed higher oral absorption of LT compared with crystalline LT. • NC/LT may be an efficacious dosage form to enhance nutraceutical properties of LT. A nanocrystal formulation of lutein (NC/LT) was prepared by particle size reduction approach with a bottom-up system to improve nutraceutical properties of LT, and physicochemical and pharmacokinetic characterizations of NC/LT were undertaken. In NC/LT, LT nanoparticles with a mean diameter of 230 nm existed in a crystalline state, and, in comparison with crystalline LT, NC/LT exhibited a marked improvement in dissolution/dispersion behavior of LT in water. Orally-administered NC/LT exhibited enhanced oral absorption of LT in male Sprague-Dawley rats, as evidenced by relative bioavailability of 15.2 to crystalline LT. After oral administration of LT samples (100 mg-LT/kg, 7 days) to male Sprague-Dawley rats, the ocular accumulation of LT in NC/LT was 3.4-fold higher than that in crystalline LT. Upon these findings, particle size reduction of LT would be efficacious to improve its dissolution and pharmacokinetic characteristics, and NC/LT may be an attractive dosage form to enhance the nutraceutical properties of LT. [ABSTRACT FROM AUTHOR]