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Viehmeister K, Manuelli A, Guerin C, Kappes S, Lamprecht A. Imaging-Based Drug Penetration Profiling in an Excised Sheep Cornea Model. Pharmaceutics 2024; 16:1126. [PMID: 39339164 PMCID: PMC11435002 DOI: 10.3390/pharmaceutics16091126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2024] [Revised: 08/04/2024] [Accepted: 08/18/2024] [Indexed: 09/30/2024] Open
Abstract
Formulations designed to address ocular conditions and diseases are predominantly administered topically. While in vitro test systems have been developed to assess corneal permeation under extended contact conditions, methods focusing on determining the penetration depth and kinetics of a substance within the cornea itself rather than through it, are scarce. This study introduces a method for time-dependent penetration depth analysis (10 and 60 min) by means of a semiquantitative imaging method in comparison with a quantitative corneal depth-cut technique, employing fluorescein sodium at concentrations of 0.2 and 0.4 mg/mL as a small molecule model substance and sheep cornea as a human surrogate. Excised tissues exhibited sustained viability in modified artificial aqueous humor and maintained thickness (746 ± 43 µm) and integrity (electrical resistance 488 ± 218 Ω∙cm2) under the experimental conditions. Both methods effectively demonstrated the expected concentration- and time-dependent depth of penetration of fluorescein sodium, displaying a significantly strong correlation. The traceability of the kinetic processes was validated with polysorbate 80, which acted as a penetration enhancer. Furthermore, the imaging-based method enabled detecting the retention of larger structures, such as hyaluronic acid and nanoemulsions from the commercial eyedrop formulation NEOVIS® TOTAL multi, inside the lacrimal layer.
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Affiliation(s)
- Karla Viehmeister
- Department of Pharmaceutics, Institute of Pharmacy, University of Bonn, Gerhard-Domagk-Str. 3, 53121 Bonn, Germany
| | - Aurélie Manuelli
- Horus Pharma, 22, Allée Camille Muffat, Inedi 5, 06200 Nice, France
| | - Camille Guerin
- Horus Pharma, 22, Allée Camille Muffat, Inedi 5, 06200 Nice, France
| | - Sebastian Kappes
- Department of Pharmaceutics, Institute of Pharmacy, University of Bonn, Gerhard-Domagk-Str. 3, 53121 Bonn, Germany
| | - Alf Lamprecht
- Department of Pharmaceutics, Institute of Pharmacy, University of Bonn, Gerhard-Domagk-Str. 3, 53121 Bonn, Germany
- Université de Franche-Comté, INSERM UMR1098 Right, 25030 Besançon, France
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Karthikeyan SK, Sundaram SM, Ve RS, Souza DD, Biswas S, Shetty MU. Design and development of a noninvasive ocular pressure estimator. Optom Vis Sci 2024; 101:164-172. [PMID: 38546758 DOI: 10.1097/opx.0000000000002114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/11/2024] Open
Abstract
SIGNIFICANCE A snapshot intraocular pressure (IOP) is ineffective in identifying the IOP peak and fluctuation, especially during sleep. Because IOP variability plays a significant role in the progression of glaucoma, monitoring the IOP, especially during sleep, is essential to capture the dynamic nature of IOP. PURPOSE We aimed to design an ocular pressure estimator (OPE) that can reliably and accurately measure the IOP noninvasively over closed-eyelid condition. METHODS Ocular pressure estimator works on the principle that the external pressure applied by raising the IOP of the eyeball is transmitted through a compressible septum to the pressure sensor, thus recording the IOP. A fluid-filled pouch with a pressure sensor was placed over a rubber glove mimicking the eyelid (septum), covering the cornea of enucleated goat eyeballs. A pressure-controlled setup was connected to a goat cadaver eye, which was validated by a rebound tonometer. Cannulation of eyeballs through the lower limbus had the least difference from the control setup values documented using rebound tonometer, compared with cannulation through the optic nerve. Intraocular pressures ranging from 3 to 30 mmHg was induced, and the outputs recorded using OPE were amplified and recorded for 10 minutes (n = 10 eyes). We stratified the randomization of the number of times and the induced pressures. RESULTS The measurements recorded were found to be linear when measured against an IOP range of 3 to 30 mmHg. The device has excellent reliability (intraclass correlation coefficient, 0.998). The repeatability coefficient and coefficient of variations were 4.24 (3.60 to 4.87) and 8.61% (7.33 to 9.90), respectively. The overall mean difference ± SD between induced IOP and the OPE was 0.22 ± 3.50 (95% confidence interval, -0.35 to 0.79) mmHg across all IOP ranges. CONCLUSIONS Ocular pressure estimator offers a promising approach for reliably and accurately measuring IOP and its fluctuation noninvasively under a condition mimicking a closed eye.
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Affiliation(s)
- Siddharth K Karthikeyan
- Department of Optometry, Manipal College of Health Professions (MCHP), Manipal Academy of Higher Education (MAHE), Manipal, Karnataka, India
| | - Swaminathan M Sundaram
- Department of Instrumentation and Control Engineering, Manipal Institute of Technology, Manipal Academy of Higher Education (MAHE), Manipal, Karnataka, India
| | - Ramesh S Ve
- Department of Optometry, Manipal College of Health Professions (MCHP), Manipal Academy of Higher Education (MAHE), Manipal, Karnataka, India
| | - Donson D Souza
- Blackfrog Technologies Pvt Ltd, Manipal, Karnataka, India
| | - Sayantan Biswas
- Department of Optometry, Manipal College of Health Professions (MCHP), Manipal Academy of Higher Education (MAHE), Manipal, Karnataka, India
- School of Optometry, College of Health and Life Sciences, Aston University, Birmingham, United Kingdom
| | - Mayur U Shetty
- Blackfrog Technologies Pvt Ltd, Manipal, Karnataka, India
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Pe'er O, Gantz L, Gal E, Ofri R. A retinoscopic survey of donkeys and goats. Vet Ophthalmol 2023; 26:385-392. [PMID: 37386869 DOI: 10.1111/vop.13126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 06/12/2023] [Accepted: 06/14/2023] [Indexed: 07/01/2023]
Abstract
PURPOSE Assess the refractive states of donkeys and goats. METHODS Forty-two donkeys and 28 goats were enrolled. The mean ± SD ages were 7.68 ± 7.33 years for donkeys and 4.26 ± 2.33 years for goats. Seven donkeys and one goat were <6 months old. Retinoscopy was performed in alert animals, following cycloplegia in goats but not in donkeys. Normality was determined using the Kolmogorov-Smirnov test. The two primary meridians and two eyes were compared using Pearson's correlation and paired Student's t-tests. The association between refractive states and age was examined using one-way ANOVA in donkeys and a paired Student's t-test in goats. One-sample t-tests were conducted to assess if the refractive error distributions were significantly different from "0". RESULTS The mean ± SD spherical equivalent (SE) refractive errors of the right and left donkey eyes were -0.80 ± 1.03 D and -0.35 ± 0.95 D, respectively. The majority (86%) of the donkeys had an astigmatic refraction and eight (19%) had anisometropia. The mean SE refractive errors of the right and left goat eyes were -0.15 ± 1.1 D and -0.18 ± 1.2 D, respectively. The majority (54%) of the goat eyes had an astigmatic refraction and five (18%) had anisometropia. The right and left eye SE refractive errors were positively correlated in both species (both p = .9). Age was not correlated with refractive error in both donkeys (p = .09) and goats (p = .6). CONCLUSIONS Both goats and donkeys are emmetropic.
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Affiliation(s)
- Oren Pe'er
- Koret School of Veterinary Medicine, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Liat Gantz
- Department of Optometry and Vision Science, Hadassah Academic College, Jerusalem, Israel
| | - Eyal Gal
- Department of Optometry and Vision Science, Hadassah Academic College, Jerusalem, Israel
| | - Ron Ofri
- Koret School of Veterinary Medicine, The Hebrew University of Jerusalem, Rehovot, Israel
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Kaviarasi B, Rajana N, Pooja YS, Rajalakshmi AN, Singh SB, Mehra NK. Investigating the Effectiveness of Difluprednate-Loaded Core-Shell Lipid-Polymeric Hybrid Nanoparticles for Ocular Delivery. Int J Pharm 2023; 640:123006. [PMID: 37137420 DOI: 10.1016/j.ijpharm.2023.123006] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 04/26/2023] [Accepted: 04/27/2023] [Indexed: 05/05/2023]
Abstract
Uveitis is a sight-threatening disease that causes inflammation in the uvea; difluprednate (DFB) is the first approved drug molecule for postoperative pain, inflammation, and endogenous uveitis. Complex ocular physiology and structure make it difficult to deliver drugs to the eye. Increased permeation and retention in the layer of the eye are required to improve the bioavailability of ocular drugs. In the current research investigation, DFB-loaded lipid polymer hybrid nanoparticles (LPHNPs) were designed and fabricated to enhance the corneal permeation and sustained release of DFB. A well-established two-step approach was used to fabricate the DFB-LPHNPs, comprising of Poly-Lactic-co-Glycolic Acid (PLGA) core that entrapped the DFB and DFB loaded PLGA NPs covered by lipid shell. The manufacturing parameters were optimized for the preparation of DFB-LPHNPs; the optimal DFB-LPHNPs showed a mean particle size of 117.3±2.9 nm, suitable for ocular administration and high entrapment efficiency of 92.45 ± 2.17 % with neutral pH (7.18 ±0.02) and isotonic Osmolality (301±3 mOsm/kg). Microscopic examination confirms the core-shell morphological structure of DFB-LPHNPs. The prepared DFB-LPHNPs were extensively characterized using spectroscopic techniques and physicochemical characterization, which confirms the entrapment of the drug and the formation of the DFB-LPHNPs. The confocal laser scanning microscopy studies revealed that Rhodamine B-loaded LPHNPs were penetrated into stromal layers of the cornea in ex-vivo conditions. The DFB-LPHNPs showed a sustained release pattern in simulated tear fluid and 4- folds enhanced permeation of DFB as compared to pure DFB solution. The ex-vivo histopathological studies revealed that DFB-LPHNPs didn't cause any damage or no alteration in the cellular structure of the cornea. Additionally, the results of the HET-CAM assay confirmed that the DFB-LPHNPs were not toxic for ophthalmic administration.
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Affiliation(s)
- B Kaviarasi
- Pharmaceutical Nanotechnology Research Laboratory, Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad, Telangana, INDIA
| | - Naveen Rajana
- Pharmaceutical Nanotechnology Research Laboratory, Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad, Telangana, INDIA
| | - Yeruva Sri Pooja
- Pharmaceutical Nanotechnology Research Laboratory, Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad, Telangana, INDIA
| | - A N Rajalakshmi
- Department of Pharmaceutics, Mother Theresa Post Graduate and Research Institute of Health Sciences, Gorimedu, Puducherry, INDIA
| | - Shashi Bala Singh
- Department of Biological Sciences, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad, Telangana, INDIA
| | - Neelesh Kumar Mehra
- Pharmaceutical Nanotechnology Research Laboratory, Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad, Telangana, INDIA.
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Villar T, Pascoli AL, Klein A, Chacaltana FC, Capistrano E, Shipley CF, Martins BC. Tear production, intraocular pressure, and central corneal thickness in white-tailed deer (Odocoileus virginianus). Vet Ophthalmol 2019; 23:123-128. [PMID: 31309707 DOI: 10.1111/vop.12696] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 06/18/2019] [Accepted: 06/21/2019] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To evaluate the tear production, intraocular pressure, and central corneal thickness in healthy white-tailed deer (Odocoileus virginianus) and assess for seasonal variability. ANIMALS STUDIED Nineteen healthy fawns (3-10 days old) and 8 healthy adult white-tailed deer (164-280 days old) were studied. PROCEDURES All fawns were manually restrained for the study, while adult animals were immobilized with an intramuscular injection of combined xylazine (2.2 mg/kg), tiletamine (1 mg/kg), and zolazepam (1 mg/kg). Tear production (STT-1) was evaluated in both eyes of all fawns. Intraocular pressure (applanation and rebound tonometry) and central corneal thickness (ultrasound pachymetry) were determined in both eyes of all fawns and adult deer. RESULTS Mean ± SD tear production in fawns was 12.32 ± 4.46 mm/min. Mean ± SD IOP values in the fawns were 16.21 ± 4.97 mm Hg (TonoPen® ) and 14.05 ± 5.03 mm Hg (TonoVet® ). In adult deer, mean ± SD IOP values were 15.57 ± 2.88 mm Hg with TonoPen® and 12.87 ± 2.57 with TonoVet® , and TonoPen® significantly overestimated the IOP, compared to TonoVet® (P < 0.005). The IOP was not significantly different between young and adult animals (P = 0.22). A significant difference (P < 0.005) in CCT values was observed between fawns (528.42 ± 27.65 μm) and adult deer (747.55 ± 41.60 μm). CONCLUSIONS This study reports normal values of tear production in healthy fawns, and intraocular pressure and central corneal thickness in healthy young and adult white-tailed deer.
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Affiliation(s)
- Tatiane Villar
- Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, Champaign-Urbana, IL, USA
| | - Ana L Pascoli
- Veterinary Clinical Medicine Department, Regional University of Blumenau, Blumenau, Brazil
| | - Aislinn Klein
- Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, Champaign-Urbana, IL, USA
| | - Flor C Chacaltana
- Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, Champaign-Urbana, IL, USA
| | - Erotides Capistrano
- Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, Champaign-Urbana, IL, USA
| | - Cliff F Shipley
- Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, Champaign-Urbana, IL, USA
| | - Bianca C Martins
- Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, Champaign-Urbana, IL, USA
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Coyo N, Leiva M, Costa D, Rios J, Peña T. Corneal thickness, endothelial cell density, and morphological and morphometric features of corneal endothelial cells in goats. Am J Vet Res 2018; 79:1087-1092. [DOI: 10.2460/ajvr.79.10.1087] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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