A review of the use of olopatadine in allergic conjunctivitis

Oral and topical administration of a geranyl acetophenone attenuates DNCB-induced atopic dermatitis-like skin lesions in BALB/c mice

Atopic dermatitis (AD) is a chronic, allergic inflammatory skin disorder that lacks a definite cure. Using a mouse DNCB-induced AD-like skin lesions model, this study evaluated the potential therapeutic utility of tHGA as an oral and topical treatment for AD. Male BALB/c mice were sensitised and challenged with 1% and 0.5% DNCB on their shaved dorsal skin. Mice in the treatment group were administered tHGA (20, 40, and 80 mg/kg) orally three times per week for 2 weeks, or tHGA (0.2%, 1%, and 5%) topically once daily for 12 days. On day 34, the mice were euthanized, and blood and dorsal skin samples were obtained for analysis. All doses of orally and topically administered tHGA significantly improved scratching, epidermal thickness, blood eosinophilia and mast cell infiltration. There was a minor discrepancy between the two routes of administration, with orally treated tHGA showing significant reductions in Scoring of Atopic Dermatitis (SCORAD), tissue eosinophil infiltration, serum IgE and skin IL-4 levels with treatment of 40 and 80 mg/kg tHGA, whereas topically applied tHGA showed significant reductions in all dosages. These findings suggest that tHGA exhibited therapeutic potential for AD as both oral and topical treatment ameliorates AD-like symptoms in the murine model.

Formulation of olopatadine hydrochloride viscous eye drops - physicochemical, biopharmaceutical and efficacy assessment using in vitro and in vivo approaches

The aim of this work was the formulation and the comprehensive evaluation of the viscous eye drops using vehicles containing medium chain chitosan (0.5% w/v), hydroxypropyl guar gum (0.25% w/v) and their combination as carriers for olopatadine (0.1% w/v). Physicochemical properties (appearance, clarity, pH, osmolality, viscosity and drug content) of the tested formulations were within acceptable ranges for the ophthalmic preparations, while DSC and FT-IR techniques demonstrated the compatibility between olopatadine and polymers. The drug permeability was successfully estimated in vitro using both HCE-T cell-based models (Model I and Model II) and the parallel artificial membrane permeability assay (PAMPA), considering the impact of chitosan as a permeation enhancer. The MTT cytotoxicity assay demonstrates that the tested formulations (diluted 10-fold in HBSS pH 5.5) were non-toxic and well tolerated. An ocular itch test on mice was carried out with the formulation containing the combination of polymers comparable with a commercially available olopatadine eye drops without viscosity enhancers. The tested eye drops produced a slightly higher anti-pruritic/analgesic-like effect than the commercial preparation. It could be assumed that the use of this viscous ophthalmic vehicle due to its advanced mucoadhesive properties and good safety profile is a feasible strategy to improve the efficacy of olopatadine.

Intrinsic Stability Study and Forced Degradation Profiling of Olopatadine Hydrochloride by RP-HPLC-DAD-HRMS Method

Objectives

Forced degradation determines the intrinsic stability of a molecule by establishing degradation pathways in order to identify the likely degradation products (DPs). The objective of the present research was to establish intrinsic stability and forced degradation profiling of olopatadine hydrochloride.

Materials and Methods

The intrinsic stability of olopatadine hydrochloride was evaluated by RP-HPLC, where a mixture of 0.1% formic acid and organic phase (methanol:acetonitrile; 50:50 % v/v) was used as mobile phase at 1.0 mL/min in gradient mode. Different stress conditions were employed to explore the intrinsic stability of olopatadine hydrochloride.

Results

In acidic condition, five DPs, i.e. OLO1, OLO2, OLO3, OLO4, and OLO5, were observed. OLO5 was the major DP that increased with time and the peak area of OLO was decreased. In addition to OLO3 and OLO5, two more DPs were observed in alkaline condition, i.e. OLO6 and OLO7. OLO5 and OLO6 were two major DPs; OLO5 increased with time while OLO6 had a zigzag pattern of peak area with time. All DPs of neutral condition were also found in acidic condition while OLO3 and OLO5 were common in all three types of hydrolytic degradation.

Conclusion

Thus, OLO has similar pattern of degradation profiling in all hydrolytic conditions (acidic, alkaline, and neutral). No degradation was found in thermal, ultraviolet light, or oxidative conditions over 10 days. OLO-Imp was recognized as an analogue structure of OLO and proposed as 11-[(3-dimethylamino)-propylidene]-6,11-dihydro-dibenz[b,e]oxepin-2-propanoic acid in standard drug. OLO1 was identified as (2-(4-(dimethylamino) butyl) phenyl)methanol, which may be formed by cleavage of the tricyclic ring in neutral condition.

Pooled analysis of two studies evaluating efficacy and safety of olopatadine hydrochloride 0.77% in patients with allergic conjunctivitis

Purpose

Two individual phase 3 conjunctival allergen challenge (CAC) studies of similar design have assessed the efficacy and safety of olopatadine hydrochloride (HCl) 0.77% for the treatment of allergic conjunctivitis. The purpose of this study is to evaluate the integrated efficacy and safety of olopatadine HCl 0.77% from a larger dataset by pooling data from the two individual CAC studies.

Methods

Data were pooled from two phase 3, randomized, multicenter, double-masked, active- and vehicle-controlled CAC studies. The primary comparison was on ocular itching scores between olopatadine HCl 0.77% versus vehicle (at onset and 24 hours) and olopatadine HCl 0.77% versus olopatadine 0.2% (at 24 hours). Additional end points included conjunctival redness, total redness, and proportion of itching responders at onset and 24-hour duration of CAC. For both primary and secondary analysis, mixed model repeated measures analysis was used, except for proportion of ocular itching responders. Sensitivity analyses were carried out using a two-sample t-test.

Results

This analysis included 448 patients. Olopatadine HCl 0.77% was superior to vehicle (P<0.0001) at onset and 24-hour duration of action (difference in means: −1.14 to −1.52) and to olopatadine 0.2% (P=0.0009) at 24-hour duration of action in relieving ocular itch. Additionally, olopatadine HCl 0.77% substantially reduced conjunctival redness and total redness over vehicle and olopatadine 0.2% at onset and 24-hour duration of action. At 24 hours CAC, there were a higher proportion of itching responders with olopatadine HCl 0.77% compared to vehicle or olopatadine 0.2% (difference in proportion of responders: 43.17%, P<0.0001, and 17.25%, P=0.0012, respectively). No safety concerns were identified.

Conclusion

This analysis confirms the findings from the individual studies. The rapid onset and prolonged duration of action (for 24 hours) of olopatadine HCl 0.77% supports once-daily dosing in the treatment of allergic conjunctivitis.

An Update on the Therapeutic Approach to Vernal Keratoconjunctivitis

Vernal keratoconjunctivitis (VKC) is an inflammatory disease of the ocular surface. It commonly occurs in the first decade of life, has a wide geographical distribution, and usually occurs in warm, dry areas. The pathogenesis of VKC seems to have an immune, nervous, and endocrine basis. The most common eye symptoms are itching, discharge, tearing, eye irritation, redness of the eyes, and photophobia. Although VKC generally has a good prognosis, the lack of clarity regarding the origin of the disease makes treatment a challenge for pediatricians and ophthalmologists. The purpose of this review is to discuss the pathogenesis, clinical features, and diagnostic criteria in VKC, with a focus on its therapeutic management. The selection of a therapeutic scheme from the many available options is based on clinical features and the personal preferences of both physicians and patients. Due to the lack of uniform grading of disease severity, there is no worldwide consensus on first-line and second-line therapeutic approaches. The choice of treatment for long-term moderate to severe VKC includes topical cyclosporine or tacrolimus. Further data are needed to define the minimal effective concentration and the safety of these drugs in eye drops and to clarify the diagnosis of VKC in patients who require these drugs. Finally, while promising newly discovered drugs are expected to enter into clinical practice, further studies on their efficacy and safety are required.

Biomimetic contact lenses eluting olopatadine for allergic conjunctivitis

Combination of the ability of contact lenses (CLs) to act as a physical barrier against airborne antigen and to serve as a sustained depot of antihistaminic drugs may improve the efficiency of treatments of some ocular allergic diseases. The aim of this work was to develop CLs that exhibit affinity to olopatadine by mimicking the composition of the natural H1-receptor for which olopatadine behaves as a selective antagonist. Functional monomers that match the chemical groups of the receptor and application of the molecular imprinting technology led to hydrogels able to load high amounts of olopatadine and to sustain the release once in contact with lachrymal fluid. Optimized hydrogels prepared with acrylic acid, 2-acrylamido-2-methyl-1-propanesulfonic acid and benzylmethacrylate as functional monomers provided in few hours olopatadine concentrations similar to those of commercially available eye drops but the levels could be sustained for a whole day, demonstrating their efficacy. Olopatadine-loaded CLs successfully passed the HET-CAM test of ocular irritancy and showed good compatibility with mast cells. They were able to inhibit the release of histamine and TNF-α from sensitized mast cells, proving their potential application in preventing and treating allergic conjunctivitis.

STATEMENT OF SIGNIFICANCE

Contact lenses (CLs) with affinity for antiallergic drugs may constitute an advantageous alternative to eye drops in management of ocular allergies for both contact lens wearers and patients who eventually use neutral CLs as therapeutic platforms. The present work represents a step forward in the state of the art of drug-CL combo products by (i) mimicking the composition of the human receptor of the drug, (ii) exploring combinations of functional monomers that include a monomer (2-acrylamido-2-methyl-1-propanesulfonic acid; AMPSA) with a strong acid group (pKa<4) able to enhance the interaction of the network with olopatadine in the saline environment of the lachrymal fluid, and (iii) analysing in detail the antihistamic effects provided by olopatadine released from the CLs on sensitized mast cells.

Topical Olopatadine in the Treatment of Allergic Conjunctivitis: A Systematic Review and Meta-analysis

PURPOSE

To assess the safety and efficacy of topical olopatadine versus placebo and other topical anti-allergic medications in treating allergic conjunctivitis.

METHODS

We systematically searched the literature for randomized-controlled trials that included patients with allergic conjunctivitis, compared olopatadine versus placebo or alternative anti-allergic medications, and examined itch, conjunctival hyperemia, composite symptom or sign scores, and/or occurrence of adverse events. We assessed the safety and efficacy of topical olopatadine when compared with placebo or alternative anti-allergic medications using meta-analysis.

RESULTS

When compared with placebo, topical olopatadine is associated with a pooled-mean difference (MD) in ocular itch of -1.33 (p < 0.00001) and ocular hyperemia of -0.92 (p < 0.00001). When compared with other agents, olopatadine was inferior to alcaftadine on ocular itch (pooled-MD = 0.39; p < 0.00001) but comparable with epinastine and ketotifen.

CONCLUSIONS

Topical olopatadine is a safe and effective treatment modality for allergic conjunctivitis, whereas alcaftadine appears to be superior to olopatadine in reducing ocular itch.

Modern approach to managing vernal keratoconjunctivitis

Vernal keratoconjunctivitis (VKC), an allergic inflammation of the conjunctiva affecting mainly children and adolescents, is categorized under the rubric of allergic conjunctivitis. Lack of uniform diagnostic and predefined staging criteria has been a bottleneck in formulating fixed guidelines to treat VKC. This lack of consensus among clinicians/researchers regarding diagnostic and grading standards has prevented us from making comparisons between the outcomes of different studies. To treat VKC, selection of a drug from many available options should be based on the duration and frequency of symptoms, grade and inflammation of giant papillae, and severity of corneal involvement. Consideration also should be given to the patient's specific needs. The basic tenet of treatment is optimal control of symptoms with a minimum of toxic side effects resulting from prolonged use of medication.

Managing a child with an external ocular disease

Children are affected by some common external diseases, including allergic conjunctivitis and blepharokeratoconjunctivitis. This workshop aims to familiarize readers with the clinical features of each along with common presentations and to discuss strategies for managing these conditions, with emphasis on newer drugs and therapies. The other group of external diseases that commonly present in children comprises persistent punctate erosions and persistent epithelial defects. Etiology is varied, and making the correct diagnosis requires a systematic approach with close inspection of the microenvironment of the eye. Common causes and treatment modalities will be discussed. Types of lubrication and how they may best be used also will be outlined.

Vernal keratoconjunctivitis: a major review

Vernal keratoconjunctivitis (VKC) is a chronic, bilateral, at times asymmetrical, seasonally exacerbated, allergic inflammation of the ocular surface, involving tarsal and/or bulbar conjunctiva. Though the allergic nature of this entity has been accepted for a long time, the accumulation of a large amount of immunological data has proved that the pathogenesis of VKC is much more complex than a mere type 1 hypersensitivity reaction. In the past several years, many clinical and experimental studies about the cells and mediators involved in initiating and perpetuating the ocular allergic inflammation have shown that T helper type 2 cells and their cytokines, corneal fibroblasts and epithelium along with various growth factors play an important role in the pathogenesis of VKC. Based on this information about the pathogenesis of VKC newer, more selective drugs like anti-chemokine receptor antibodies and leukotriene receptor antagonists are under evaluation. Cyclosporine has been shown to be effective in the treatment of VKC but further randomized control trials are required to establish the minimum effective concentration.