An in vitro comparison of the permeability of prednisolone, prednisolone sodium phosphate, and prednisolone acetate across the NZW rabbit cornea

Non-Infectious Uveitis and Pregnancy, is There an Optimal Treatment? Uveitis Course and Safety of Uveitis Treatment in Pregnancy

In pregnancy, a plethora of factors causes changes in maternal immunity. Uveitis flare-ups are more frequent in the first trimester and in undertreated patients. Management of non-infectious uveitis during pregnancy remains understudied. A bibliographic review to consolidate existing evidence was performed by a multidisciplinary group of Ophthalmologists, Gynaecologists and Rheumatologists. Our group recommends initial management with minimum-required doses of corticosteroids, preferably locally, to treat intraocular inflammation whilst ensuring good neonatal outcomes. If ineffective, clinicians should consider addition of Cyclosporine, Azathioprine or Certolizumab pegol, which are seemingly safe in pregnancy. Other therapies (such as Methotrexate, Mycophenolate Mofetil and alkylating agents) are teratogenic or have a detrimental effect on the foetus. Furthermore, careful multidisciplinary preconception discussions and close follow-up are recommended, monitoring for flare-ups and actively tapering medication doses, with a primary endpoint focused on protecting ocular tissues from inflammation, whilst giving minimal risk of poor pregnancy and foetal outcomes.

Topical Ocular Therapeutics in Small Animals

This article reviews the administration of common topical ophthalmic medications, in relation to factors influencing absorption including composition of topical ophthalmic preparations, and potential systemic effects. Commonly prescribed, commercially available topical ophthalmic medications are discussed with respect to pharmacology, their indications for use, and adverse effects. Knowledge of topical ocular pharmacokinetics is essential for the management of veterinary ophthalmic disease.

Enhanced topical corticosteroids delivery to the eye: A trade-off in strategy choice

Topical corticosteroids are the primary treatment of ocular inflammation caused by surgery, injury, or other conditions. Drug pre-corneal residence time, drug water solubility, and drug corneal permeability coefficient are the major factors that determine the ocular drug bioavailability after topical administration. Although growing research successfully enhanced local delivery of corticosteroids utilizing various strategies, rational and dynamic approaches to strategy selection are still lacking. Within this review, an overview of the various strategies as well as their performance in retention, solubility, and permeability coefficient of corticosteroids are provided. On this basis, the tradeoff of strategy selection is discussed, which may shed light on the rational choice and application of ophthalmic delivery enhancement strategies.

Corticosteroids in ophthalmology: drug delivery innovations, pharmacology, clinical applications, and future perspectives

Corticosteroids remain the mainstay of the treatment for various ocular conditions affecting the ocular surface, anterior and posterior segments of the eye due to their anti-inflammatory, anti-oedematous, and anti-neovascularization properties. Prednisolone, prednisolone acetate, dexamethasone, triamcinolone acetonide, fluocinolone acetonide, and loteprednol etabonate are amongst the most widely used ophthalmic corticosteroids. Corticosteroids differ in their activity and potency in the eye due to their inherent pharmacological and pharmaceutical differences. Different routes and regimens are available for ocular administration of corticosteroids. Conventional topical application to the eye is the route of choice when targeting diseases affecting the ocular surface and anterior segment, while periocular, intravitreal, and suprachoroidal injections can be potentially effective for posterior segment diseases. Corticosteroid-induced intraocular pressure elevation and cataract formation remain the most significant local risks following topical as well as systemic corticosteroid administration. Invasive drug administration via intracameral, subconjunctival, and intravitreal injection can enhance ocular bioavailability and minimize dose and dosing frequency of administration, yet may exacerbate ocular side effects of corticosteroids. This review provides a critical appraisal of the ophthalmic uses of corticosteroid, routes of administration, drug delivery fundamentals and novel ocular implantable steroid delivery systems, factors influencing side effects, and future perspectives for ocular corticosteroid therapy.

2019 American College of Rheumatology/Arthritis Foundation Guideline for the Screening, Monitoring, and Treatment of Juvenile Idiopathic Arthritis-Associated Uveitis

OBJECTIVE

To develop recommendations for the screening, monitoring, and treatment of uveitis in children with juvenile idiopathic arthritis (JIA).

METHODS

Pediatric rheumatologists, ophthalmologists with expertise in uveitis, patient representatives, and methodologists generated key clinical questions to be addressed by this guideline. This was followed by a systematic literature review and rating of the available evidence according to the GRADE (Grading of Recommendations Assessment, Development and Evaluation) methodology. A group consensus process was used to compose the final recommendations and grade their strength as conditional or strong.

RESULTS

Due to a lack of literature with good quality of evidence, recommendations were formulated on the basis of available evidence and a consensus expert opinion. Regular ophthalmic screening of children with JIA is recommended because of the risk of uveitis, and the frequency of screening should be based on individual risk factors. Regular ophthalmic monitoring of children with uveitis is recommended, and intervals should be based on ocular examination findings and treatment regimen. Ophthalmic monitoring recommendations were strong primarily because of concerns of vision-threatening complications of uveitis with infrequent monitoring. Topical glucocorticoids should be used as initial treatment to achieve control of inflammation. Methotrexate and the monoclonal antibody tumor necrosis factor inhibitors adalimumab and infliximab are recommended when systemic treatment is needed for the management of uveitis. The timely addition of nonbiologic and biologic drugs is recommended to maintain uveitis control in children who are at continued risk of vision loss.

CONCLUSION

This guideline provides direction for clinicians and patients/parents making decisions on the screening, monitoring, and management of children with JIA and uveitis, using GRADE methodology and informed by a consensus process with input from rheumatology and ophthalmology experts, current literature, and patient/parent preferences and values.

2019 American College of Rheumatology/Arthritis Foundation Guideline for the Screening, Monitoring, and Treatment of Juvenile Idiopathic Arthritis-Associated Uveitis

OBJECTIVE

To develop recommendations for the screening, monitoring, and treatment of uveitis in children with juvenile idiopathic arthritis (JIA).

METHODS

Pediatric rheumatologists, ophthalmologists with expertise in uveitis, patient representatives, and methodologists generated key clinical questions to be addressed by this guideline. This was followed by a systematic literature review and rating of the available evidence according to the GRADE (Grading of Recommendations Assessment, Development and Evaluation) methodology. A group consensus process was used to compose the final recommendations and grade their strength as conditional or strong.

RESULTS

Due to a lack of literature with good quality of evidence, recommendations were formulated on the basis of available evidence and a consensus expert opinion. Regular ophthalmic screening of children with JIA is recommended because of the risk of uveitis, and the frequency of screening should be based on individual risk factors. Regular ophthalmic monitoring of children with uveitis is recommended, and intervals should be based on ocular examination findings and treatment regimen. Ophthalmic monitoring recommendations were strong primarily because of concerns of vision-threatening complications of uveitis with infrequent monitoring. Topical glucocorticoids should be used as initial treatment to achieve control of inflammation. Methotrexate and the monoclonal antibody tumor necrosis factor inhibitors adalimumab and infliximab are recommended when systemic treatment is needed for the management of uveitis. The timely addition of nonbiologic and biologic drugs is recommended to maintain uveitis control in children who are at continued risk of vision loss.

CONCLUSION

This guideline provides direction for clinicians and patients/parents making decisions on the screening, monitoring, and management of children with JIA and uveitis, using GRADE methodology and informed by a consensus process with input from rheumatology and ophthalmology experts, current literature, and patient/parent preferences and values.

Molecular design for enhancement of ocular penetration

Over the past two decades, many oral drugs have been designed in consideration of physicochemical properties to attain optimal pharmacokinetic properties. This strategy significantly reduced attrition in drug development owing to inadequate pharmacokinetics during the last decade. On the other hand, most ophthalmic drugs are generated from reformulation of other therapeutic dosage forms. Therefore, the modification of formulations has been used mainly as the approach to improve ocular pharmacokinetics. However, to maximize ocular pharmacokinetic properties, a specific molecular design for ocular drug is preferable. Passive diffusion of drugs across the cornea membranes requires appropriate lipophilicity and aqueous solubility. Improvement of such physicochemical properties has been achieved by structure optimization or prodrug approaches. This review discusses the current knowledge about ophthalmic drugs adapted from systemic drugs and molecular design for ocular drugs. I propose the approaches for molecular design to obtain the optimal ocular penetration into anterior segment based on published studies to date.

Ocular Permeability Screening of Dexamethasone Esters Through Combined Cellular and Tissue Systems

Dexamethasone transport across ocular epithelium was evaluated by means of permeability studies on a series of ester prodrugs with the aim of identifying the most promising candidates for the treatment of the ocular surface. Organotypic conjunctival bovine epithelial cell cultures were assumed representative of an average ocular epithelium and used to describe the mechanism of permeation. Permeability coefficients were also determined in excised rabbit corneas set up and in vivo pharmacokinetic experiments. All dexamethasone esters permeated through the transcellular route and their permeability coefficient rose with the increase of the molecules lipophilicity until a maximum was reached in correspondence of dexamethasone butyrate (Log P = 3.95). It was found that esters hydrolysis occurring in various extent along the transport process, affected the overall permeability rate. There was evidence that the permeation process can be confined at the ocular epithelium layer if the ester is highly hydrophobic and not susceptible of fast hydrolysis.

Biopharmaceutical considerations in topical ocular drug delivery

1. Despite the accessibility of the front of the eye, efficient delivery of drug to treat various ocular disorders is a challenge to the formulation scientist. The majority of ophthalmic medications are formulated as eye drops. Due to anatomical constraints, the volume that can be administered is limited to approximately 30 microL. This, together with the efficient clearance system that exists in the front of the eye, makes it difficult to maintain an effective pre-ocular drug concentration for a desired length of time. Various formulation strategies have been used to increase pre-ocular retention of eye drops. The most successful of these has been the inclusion of viscosity enhancing polymers, particularly those able to interact with the mucous layer on the eye surface or those that can undergo a transition from a solution to a gel under the conditions of the pre-ocular area. 2. When the target site is intra-ocular, drug must be absorbed from the pre-ocular region into the eye. The main route for absorption is across the cornea. However, absorption of drug across the cornea is inefficient due to its impermeable nature and small surface area. Thus, the intra-ocular bioavailability of topically administered medications is typically less than 10%. 3. Corneal permeability favours moderately lipophilic compounds. These compounds often have a low aqueous solubility. Problems in ocular drug delivery and formulation are compounded for poorly soluble drugs that must be formulated as suspensions. 4. Reformulation of ophthalmic suspensions as solutions has many advantages. This may be achieved by complexation using cyclodextrins. Solubilization using cyclodextrins can overcome many of the formulation problems. However, it is unclear as to their potential for improving ocular bioavailability, which is seemingly drug dependent and may be influenced by both the physicochemical properties of the drug and the complex formed.

Permeability of cornea, sclera, and conjunctiva: a literature analysis for drug delivery to the eye

The objective of this study was to collect a comprehensive database of ocular tissue permeability measurements found in a review of the literature to guide models for drug transport in the eye. Well over 300 permeability measurements of cornea, sclera, and conjunctiva, as well as corneal epithelium, stroma, and endothelium, were obtained for almost 150 different compounds from more than 40 different studies. In agreement with previous work, the corneal epithelium was shown generally to control transcorneal transport, where corneal stroma and endothelium contribute significantly only to the barrier for small, lipophilic compounds. In addition, other quantitative comparisons between ocular tissues are presented. This study provides an extensive database of ocular tissue permeabilities, which should be useful for future development and validation of models to predict rates of drug delivery to the eye.