Precorneal retention of topically instilled micronized particles

Sieg, James W.; Triplett, J. W.

doi:10.1002/jps.2600690735

Cited by 21 publications

(3 citation statements)

References 4 publications

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“…Retention of any of the four microparticle types, when administered as a suspension, was relatively poor, with just 1 – 10 % remaining after 10 min and even less at later times. We believe that this poor retention can be partially explained by the co-administration of eye drop carrier fluid to the preocular space, which is known to expedite tear drainage and thus remove microparticles more rapidly 29, 30…”

Section: Resultsmentioning

confidence: 99%

Mucoadhesive Microdiscs Engineered for Ophthalmic Drug Delivery: Effect of Particle Geometry and Formulation on Preocular Residence Time

Choy

Park

McCarey

et al. 2008

Invest. Ophthalmol. Vis. Sci.

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Purpose To test the hypothesis that mucoadhesive microdiscs formulated in a rapidly dissolving tablet can increase preocular residence time. Methods Microparticles, smaller than 10 μm in diameter, were fabricated by emulsification with poly(lactic-co-glycolic acid) (PLG) as a core material and, in some cases, poly(ethylene glycol) (PEG) as a mucoadhesion promoter. To examine the effect of particle geometry, microparticles were also cut to possess flat surfaces (i.e., microdiscs) and compared with spherical particles (i.e., microspheres). In vitro mucoadhesion of microparticles was tested on a mucous layer under shear stress mimicking the human blink. The resulting microparticles were also formulated in two dosage forms – an aqueous suspension and dry tablet to – test the effect of formulation on the retention capacity of microparticles on the preocular space of rabbits in vivo. Results Mucoadhesive microdiscs adhered better to the simulated ocular surface than the other types of microparticles. When a dry tablet embedded with mucoadhesive microdiscs was administered in the cul-de-sac of the rabbit eye in vivo, these microdiscs exhibited longer retention than the other formulations tested in this work. More than 40% and 17% of mucoadhesive microdiscs remained on the preocular surface at 10 min and 30 min after administration, respectively. Fluorescence images from the eye surface showed that mucoadhesive microdiscs remain for at least 1 h in the lower fornix. Conclusion This study demonstrated that mucoadhesive microdiscs formulated in a dry tablet can achieve a prolonged residence time on the preocular surface and thus are a promising drug delivery system for ophthalmic applications.

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Section: Resultsmentioning

confidence: 99%

Mucoadhesive Microdiscs Engineered for Ophthalmic Drug Delivery: Effect of Particle Geometry and Formulation on Preocular Residence Time

Choy

Park

McCarey

et al. 2008

Invest. Ophthalmol. Vis. Sci.

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“…According to Schoenwald and Stewart, a smaller mean particle size in 0.1% dexamethasone suspensions resulted in greater drug levels in the cornea and aqueous humor 24 . However, particles that are too small may undergo faster elimination from the conjunctival sac; therefore, there is a lower limit for particle-size retention and an upper limit for ocular surface irritation 25 . Consequently, the active substance water solution may also be characterized by shorter retention in the conjunctival sac and fewer negative effects on the ocular surface.…”

Section: Discussionmentioning

confidence: 99%

Assessment of the eye surface and subjective symptoms after using 0.1% dexamethasone drops with and without preservatives in patients after cataract surgery

Muzyka-Woźniak,

Stróżecki,

Przeździecka-Dołyk

2023

Sci Rep

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Cataract surgery can cause dry eye symptoms. One of the many factors compromising the ocular surface is the use of benzalkonium chloride (BAC)-preserved topical eye drops administered during the postoperative period. In this open-label, prospective, randomized, comparative clinical trial, 40 patients not previously affected by dry eye disease were assigned to receive either preservative-free (PFD) or preserved (PD) dexamethasone 0.1% eye drops for two weeks after a standard phacoemulsification procedure. Fluorescein break-up time, ocular surface staining score, Schirmer test, Ocular Surface Disease Index and anterior chamber (AC) cells were evaluated at baseline prior to the surgery and 2 weeks after surgery. No statistically significant differences in baseline assessments were observed between groups. At week 2, a significant increase in corneal staining scores (p = 0.003) and foreign body sensation (p = 0.04) was observed for the PD group only. The conjunctival staining score was significantly higher in both groups. The mean AC cell grading was higher in the PFD group than in the PD group (0.28 ± 0.30 and 0.07 ± 0.18, respectively; p = 0.013). Preservative-free dexamethasone eye drops after cataract surgery caused milder dry eye symptoms as compared with preserved dexamethasone. The AC inflammation control comparison may require a larger study group. Trial registration: ClinicalTrials.gov identifier NCT05753787, 03/03/2023.

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“…According to studies conducted to determine the effect of particle size on bioavailability, a particle size in this particular range is near ideal so that this particular parameter was not suspected.2'. 22 The ointment contained mineral oil, petrolatum, chlorobutanol, and fluorometholone acetate and therefore could be classified as a suspension. Bulk diffusion would be expected to be negligible.…”

Section: Discussionmentioning

confidence: 99%

Ophthalmic bioequivalence of steroid/antibiotic combination formulations

Schoenwald

Harris

Turner

et al. 1987

Biopharm & Drug Disp

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This study compared the relative ocular bioavailability in rabbits of the antibiotic/steroid combination of 0.3 per cent tobramycin and 0.1 per cent fluorometholone acetate to each of the two single-entity products. Two separate studies were conducted, one measuring fluorometholone acetate in cornea and aqueous humour through 240 min and the other measuring tobramycin in the cornea through 120 min. The results for fluorometholone acetate show that the combination product is 15 per cent higher in AUC for the cornea than the single-entity product (0.05 less than p less than 0.1). However, the combination product is only 4.4 per cent higher in AUC when aqueous humour levels are compared (N.S.). The single-entity fluorometholone acetate ointment yielded cornea and aqueous humour levels which were 20 per cent (p less than 0.01) and 6 per cent (N.S.) higher in AUC than the same tissues measured after topical instillation of the suspension. Statistical treatment of the data indicated that the suspension and ointment products, were bioequivalent with respect to fluorometholone acetate in aqueous humour, but not with respect to corneal concentrations. Tobramycin was measured in the cornea following instillation of either the single-entity solution or the combination suspension. Per cent bound (tobramycin to rabbit antibodies determined in vitro from the radioimmunoassay results) was used for statistical analyses of all group means and standard errors. The results indicated that the products were bioinequivalent.

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Precorneal retention of topically instilled micronized particles

Cited by 21 publications

References 4 publications

Mucoadhesive Microdiscs Engineered for Ophthalmic Drug Delivery: Effect of Particle Geometry and Formulation on Preocular Residence Time

Mucoadhesive Microdiscs Engineered for Ophthalmic Drug Delivery: Effect of Particle Geometry and Formulation on Preocular Residence Time

Assessment of the eye surface and subjective symptoms after using 0.1% dexamethasone drops with and without preservatives in patients after cataract surgery

Ophthalmic bioequivalence of steroid/antibiotic combination formulations

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