Ocular Distribution of Cyclosporine Following Topical Administration of OTX-101 in New Zealand White Rabbits

Evaluation of adjuvant role of topical cyclosporine 1% in acute Stevens-Johnson syndrome: a randomised control trial

PURPOSE

To evaluate the role of topical cyclosporine A 1% (CsA) as an adjuvant therapy in patients with acute Stevens-Johnson syndrome (SJS).

METHODS

This is a randomised controlled trial in which 44 patients (88 eyes) with acute SJS, presenting within 3 months from the onset of the disease, were enrolled and randomised. Group A (n=44 eyes) patients received treatment with topical CsA 1% along with standard therapy consisting of topical corticosteroids, antibiotics and lubricants. Group B (n=44 eyes) patients received topical saline drops in combination with standard therapy. Various ocular surface parameters were assessed at baseline and the 6-month follow-up.

RESULTS

The mean age of patients (years) was 23.9±15.1 in the CsA group and 26.0±18.7 in the control group (p=0.6840). The mean time from disease onset to presentation (days) was 17.0±14.0 and 12.9±11.3 in CsA and control groups, respectively (p=0.1568). At presentation, the mean grades of severity scores of various parameters were comparable. At 6 months, both groups showed a significant improvement in the mean severity grades of conjunctival hyperaemia (A, p=0.001; B, p=0.0001), mucocutaneous junction involvement (A, p=0.001; B, p=0.0001) and meibomian gland involvement (A, p=0.0471; B, p=0.006). Compared with baseline, the grades of corneal keratinisation (baseline, 0.48±0.7; 6 months, 1.02±0.8; p=0.0015) and neovascularisation (baseline, 1.07±1.2; 6 months, 1.57±1.0; p=0.0412) worsened after 6 months of CsA therapy. Intergroup comparison of grades of various parameters however did not reveal any significant difference at 6 months.

CONCLUSIONS

Adjuvant treatment with topical CsA is not superior to standard therapy, in cases of acute SJS.

Studies on cationic ocular emulsions containing bipartitioned oil droplets to codeliver cyclosporin A and etodolac

Background: To prepare ocular emulsions containing bipartitioned oil droplets to entrap cyclosporin A (0.05% w/w) and etodolac (0.2% w/w) by using castor, olive and silicon oils. Methods: The physicochemical characterizations of prepared emulsions were performed. The drug's biodistribution profiles and pharmacokinetic parameters from emulsions were checked using the ultraperformance liquid chromatography-tandem mass spectrometry method in the ocular tissues of the healthy rabbit eye model. Results: The emulsions displayed 365.13 ± 7.21 nm size and 26.45 ± 2.09 mV zeta potential. The ferrying of two drugs after releasing from emulsions occurred across corneal/conjunctival tissues to enter the vitreous and sclera following a single drop administration into the rabbit's eyes. Conclusion: The dual drug-loaded emulsions were more likely to produce synergistic anti-inflammatory activity for managing moderate-to-severe dry eye disease.

Recent Advances in Nanotechnology for the Treatment of Dry Eye Disease

Dry eye disease (DED) incidence is continuously growing, positioning it to become an emergent health issue over the next few years. Several topical treatments are commonly used to treat DED; however, reports indicate that only a minor proportion of drug bioavailability is achieved by the majority of eye drops available on the market. In this context, enhancing drug ability to overcome ocular barriers and prolonging its residence time on the ocular surface represent a new challenge in the field of ocular carrier systems. Therefore, research has focused on the development of multi-functional nanosystems, such as nanoemulsions, liposomes, dendrimers, hydrogels, and other nanosized carriers. These systems are designed to improve topical drug bioavailability and efficacy and, at the same time, require fewer daily administrations, with potentially reduced side effects. This review summarizes the different nanotechnologies developed, their role in DED, and the nanotechnology-based eyedrops currently approved for DED treatment.

New advances in medical management of dry eye: optimizing treatment strategies for enhanced relief

PURPOSE

Dry eye disease (DED) is a prevalent ocular surface disease that is conventionally characterized by tear film hyperosmolarity and instability. This review presents a summarized classification of DED, followed by a comprehensive discussion of the most recent topical and systemic medications and clinical recommendations for selecting the most appropriate option for each patient.

METHODS

An extensive literature search was conducted on electronic databases, such as PubMed, Scopus, and Web of Science, using keywords including "dry eye syndrome," "ocular surface disease," "medical management," "artificial tears," "topical immunomodulators," and "meibomian gland dysfunction."

RESULTS

The underlying reasons for DED can range from insufficient aqueous tear production to increased tear evaporation. Recent literature has provided a more in-depth understanding of the pathophysiology of DED by examining the tear film's lipid, aqueous, and mucin layers. However, despite these advancements, medical management of patients with symptomatic DED has not fully reflected this modernized knowledge of its pathophysiology.

CONCLUSION

To develop a rationalized strategy for treating DED, it is crucial to have updated knowledge of therapeutic options, their mechanisms of actions, and indications based on the DED type and underlying causes.

Rapidly Dissolving Trans-scleral Microneedles for Intraocular Delivery of Cyclosporine A

Cyclosporine A (CsA) is a cyclic peptide immunosuppressant drug that is beneficial in the treatment of various ocular diseases. However, its ocular bioavailability in the posterior eye is limited due to its poor aqueous solubility. Conventional CsA formulations such as a solution or emulsion permeate poorly across the eye due to various static and dynamic barriers of the eye. Dissolvable microneedle (MN)-based patches can be used to overcome barrier properties and, thus, enhance the ocular bioavailability of CsA in the posterior eye. CsA-loaded dissolvable MN patches were fabricated using polyvinylpyrrolidone (PVP) and characterized for MN uniformity and sharpness using SEM. Further characterization for its failure force, penetration force, and depth of penetration were analyzed using a texture analyzer. Finally, the dissolution time, ex vivo permeation, and ocular distribution of cyclosporine were determined in isolated porcine eyes. PVP MNs were sharp, uniform with good mechanical properties, and dissolved within 5 min. Ocular distribution of CsA in a whole porcine eye perfusion model showed a significant increase of CsA levels in various posterior segment ocular tissues as compared to a topically applied ophthalmic emulsion (Restasis®) (P < 0.001). Dissolving MNs of CsA were prepared, and the MN arrays can deliver CsA to the back of the eye offering potential for treating various inflammatory diseases.

Role of topical and systemic immunosuppression in aqueous-deficient dry eye disease

Immunosuppression in aqueous-deficient dry eye disease (ADDE) is required not only to improve the symptoms and signs but also to prevent further progression of the disease and its sight-threatening sequelae. This immunomodulation can be achieved through topical and/or systemic medications, and the choice of one drug over the other is determined by the underlying systemic disease. These immunosuppressive agents require a minimum of 6-8 weeks to achieve their beneficial effect, and during this time, the patient is usually placed on topical corticosteroids. Antimetabolites such as methotrexate, azathioprine, and mycophenolate mofetil, along with calcineurin inhibitors, are commonly used as first-line medications. The latter have a pivotal role in immunomodulation since T cells contribute significantly to the pathogenesis of ocular surface inflammation in dry eye disease. Alkylating agents are largely limited to controlling acute exacerbations with pulse doses of cyclophosphamide. Biologic agents, such as rituximab, are particularly useful in patients with refractory disease. Each group of drugs has its own side-effect profiles and requires a stringent monitoring schedule that must be followed to prevent systemic morbidity. A customized combination of topical and systemic medications is usually required to achieve adequate control, and this review aims to help the clinician choose the most appropriate modality and monitoring regimen for a given case of ADDE.

Cellulose Acetate Phthalate-Based pH-Responsive Cyclosporine A-Loaded Contact Lens for the Treatment of Dry Eye

Cyclosporine A (CsA) as an eye drop is an effective treatment for dry eye. However, it has potential side effects and a short ocular residence time. To overcome these obstacles, we developed a cellulose acetate phthalate-based pH-responsive contact lens (CL) loaded with CsA (CsA-CL). The CsA was continuously released from the CsA-CL at physiological conditions (37 °C, pH 7.4) without an initial burst. CsA was well-contained in the selected storage condition (4 °C, pH 5.4) for as long as 90 days. In safety assays, cytotoxicity, ocular irritation, visible light transmittance, and oxygen permeability were in a normal range. CsA concentrations in the conjunctiva, cornea, and lens increased over time until 12 h. When comparing the therapeutic efficacy between the normal control, experimental dry eye (EDE), and treatment groups (CsA eye drop, naïve CL, and CsA-CL groups), the tear volume, TBUT, corneal fluorescein staining at 7 and 14 days, conjunctival goblet cell density, and corneal apoptotic cell counts at 14 days improved in all treatment groups compared to EDE, with a significantly better result in the CsA-CL group compared with other groups (all p < 0.05). The CsA-CL could be an effective, stable, and safe option for inflammatory dry eye.

Novel drug delivery systems for the management of dry eye

Dry eye disease (DED) is a frequently observed eye complaint, which has recently attracted considerable research interest. Conventional therapy for DED involves the use of artificial tear products, cyclosporin, corticosteroids, mucin secretagogues, antibiotics and nonsteroidal anti-inflammatory drugs. In addition, ocular drug delivery systems based on nanotechnology are currently the focus of significant research effort and several nanotherapeutics, such as nanoemulsions, nanosuspensions, microemulsions, liposomes and nanomicelles, are in clinical trials and some have FDA approval as novel treatments for DED. Thus, there has been remarkable progress in the design of nanotechnology-based approaches to overcome the limitations of ophthalmic formulations for the management of anterior eye diseases. This review presents research results on diagnostic methods for DED, current treatment options, and promising pharmaceuticals as future therapeutics, as well as new ocular drug delivery systems.

Dual Delivery of Cyclosporin A and Etodolac Using Polymeric Nanocapsules in a Rabbit Eye Model: Ocular Biodistribution and Pharmacokinetic Study

Purpose: Commercially available eye drops are loaded only with a single drug. By using the polymeric nanocapsules, dual delivery of 0.05% w/w cyclosporin A (CsA) and 0.2% w/w etodolac (Edc) was achieved. An ultraperformance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) method was developed for determining simultaneously the biodistribution and pharmacokinetic profile of CsA and Edc in ocular tissues. Methods: After one single drop instillation of nanocapsules into healthy right eyes of rabbits, the eyeballs were enucleated at 5, 15, 30, 60, and 90 min time periods to separate the 5 different ocular tissues. A liquid/liquid extraction method was used for ocular sample extraction using darunavir as internal standard. Using 3 diverse conditions such as bench-top, autosampler, and freeze-thaw, the stability of the analytes at 3 quality control samples in ocular tissues was also checked. Results: Intra- and interday precisions for both CsA and Edc in multiple ocular tissues were <10.32%, and the accuracy was <11.98%. The % bias and % RSD values for CsA and Edc were found within the acceptable limit of ±15%. The highest C_max values were attained in cornea for both the drugs at 60 min postinstillation time point. Despite molecular size and structural differences, both CsA and Edc after liberation from nanocapsule drops can permeate into the tissues of the anterior as well as posterior segments of the eye. Conclusion: The biodistribution and pharmacokinetic data might help and strengthen our understanding of synergetic anti-inflammatory activity of CsA and Edc from nanocapsules after its ocular topical application for managing keratoconjunctivitis sicca.

Review of Preclinical Outcomes of a Topical Cationic Emulsion of Cyclosporine A for the Treatment of Ocular Surface Diseases

BACKGROUND

Cyclosporine A (CsA) has been used as a topical treatment for various ocular surface diseases including dry eye disease (DED). Several CsA formulations are available as solutions or emulsions.

PURPOSE

This review describes the development and the preclinical testing of a cationic oil-in-water emulsion of CsA (CE-CsA) in terms of pharmacodynamics, pharmacokinetics, and ocular tolerance. Due to the cationic charge, CE electrostatically interacts with the negatively-charged ocular surface, improving its residence time. Compared to other CsA formulations, CE-CsA and CE itself were found to reduce the signs and symptoms of DED, by restoring tear film stability and properties, and inhibiting the expression and secretion of pro-inflammatory factors. No delay in wound healing nor ocular toxicity were observed using CE formulations.

CONCLUSION

these findings indicate that the type of vehicle can significantly affect the performance of eye drops and play an ancillary role in DED treatment. CE appears as a promising strategy to deliver drugs to the ocular surface while maintaining its homeostasis.

The Use of Polymer Blends in the Treatment of Ocular Diseases

The eye is an organ with limited drug access due to its anatomical and physiological barriers, and the usual forms of ocular administration are limited in terms of drug penetration, residence time, and bioavailability, as well as low patient compliance. Hence, therapeutic innovations in new drug delivery systems (DDS) have been widely explored since they show numerous advantages over conventional methods, besides delivering the content to the eye without interfering with its normal functioning. Polymers are usually used in DDS and many of them are applicable to ophthalmic use, especially biodegradable ones. Even so, it can be a hard task to find a singular polymer with all the desirable properties to deliver the best performance, and combining two or more polymers in a blend has proven to be more convenient, efficient, and cost-effective. This review was carried out to assess the use of polymer blends as DDS. The search conducted in the databases of Pubmed and Scopus for specific terms revealed that although the physical combination of polymers is largely applied, the term polymer blend still has low compliance.

Selective Pharmacologic Therapies for Dry Eye Disease Treatment: Efficacy, Tolerability, and Safety Data Review from Preclinical Studies and Pivotal Trials

Keratoconjunctivitis sicca, also known as dry eye disease (DED), is a prevalent, multifactorial disease associated with compromised ocular lubrication, ocular surface inflammation and damage, and ocular symptoms. Several anti-inflammatory, topical ophthalmic therapies are available to treat clinical signs and symptoms of DED in the USA and Europe. Cyclosporine A (CsA)-based formulations include an ophthalmic emulsion of 0.05% CsA (CsA 0.05%), a cationic emulsion (CE) of CsA 0.1% (CsA CE), and an aqueous nanomicellar formulation of 0.09% CsA (OTX-101). Lifitegrast is a 5% ophthalmic solution of a lymphocyte function-associated antigen 1 antagonist that is believed to target T cell activation and recruitment to inhibit ocular inflammation. Here we provide a comprehensive review summarising preclinical studies and pivotal trial data for these treatments to provide a complete understanding of their efficacy and safety profile. Overall, data in the evaluated studies show a favourable risk-benefit profile for the use of targeted topical anti-inflammatory pharmacologic treatments in patients with DED. Pivotal trials for CsA 0.05%, CsA CE, OTX-101, and lifitegrast clearly demonstrate treatment efficacy compared to vehicle across treatments with no serious ocular treatment-emergent adverse events (TEAEs). Patients using ophthalmic treatments reported ocular TEAEs more frequently than those treated with vehicle; however, relatively few TEAEs led to treatment discontinuation. The specific signs and symptoms of DED that improve with treatment vary with the treatment prescribed. Long-term and direct comparative studies between treatments are needed to further understand treatment differences in efficacy and safety profiles.

Transdermal anti-inflammatory therapy for aqueous deficiency

PURPOSE

Lacrimal gland inflammation has been identified as an important limitation on aqueous production and associated dry eye disease. Ocular surface inflammation in dry eye disease can be a downstream response to reduced quantities of warmer hyperosmotic aqueous being delivered from an inflamed lacrimal gland with high concentrations of inflammatory mediators. This review examines evidence which shows how topical applications of anti-inflammatory drugs have very limited access to the lacrimal gland and an associated limited capacity to increase aqueous flow by reducing inflammation in the main lacrimal gland.

RECENT FINDINGS

Using cyclosporine as an exemplar immunomodulatory drug, this review examines problems associated with the topical administration of all anti-inflammatory drugs in the treatment of dry eye disease.

SUMMARY

Limited access to the lacrimal gland for topical applications and their very short on-eye residence times are compared with the therapeutic potential of prolonged therapeutic episodes that could be achieved with transdermal applications of a drug to the skin at the site of the lacrimal gland. Poor access to the lacrimal gland for topically administered drugs is a major barrier to the treatment of aqueous deficiency. While topical inflammatory drug access to the ocular surface is direct, poor access to the lacrimal gland is partly due to drop placement being downstream to the flow of aqueous (Eye Vis 2020;7:1; Eye Vis 2019;6:1). This barrier is much greater according to the degree that reflex tear flow is stimulated by irritation associated with adverse drop temperature, and/or pH and/or tonicity for example.

Inhibiting corneal neovascularization by sustainably releasing anti-VEGF and anti-inflammation drugs from silica-thermogel nanohybrids

Corneal neovascularization (CNV) is one of the main factors that induce blindness worldwide. To effectively inhibit CNV, a novel nanohybrid has been developed by incorporating anti-VEGF bevacizumab (BEV)-loaded mesoporous silica nanoparticles (BEV@MSN) into the thermogel matrix with anti-inflammation cyclosporine A (CsA) (BEV@MSN-CsA@Thermogel). This nanohybrid regulates the in vitro release of both bevacizumab and cyclosporine A in a sustainable way for up to four weeks to enhance CNV inhibition through the synergistic anti-VEGF and anti-inflammation. The carrier materials (i.e. silica and thermogel) in this nanohybrid do not show any cytotoxicity to human Tenon's fibroblasts, corneal epithelial cells and corneal endothelial cells. BEV@MSN-CsA@Thermogel effectively prevents proliferation, migration, and tube-like structure formation of human umbilical vein endothelial cells. Moreover, subconjunctival injection of BEV@MSN-CsA@Thermogel significantly inhibits corneal neovascularization in terms of the CNV area, the new vessel length, the corneal opaque area, the corneal inflammation and abnormal fibrosis in a rabbit model. This nanohybrid is thus a promising alternative for effective CNV treatment.

Current and Future Pharmacological Therapies for the Management of Dry Eye

Dry eye disease (DED) is among the most common reasons for visiting eye care practitioners and represents a substantial health and cost burden. Disease prevalence ranges from 5% to 33% and is increasing in the younger population. The core mechanism of DED involves a vicious cycle where hyperosmolarity leads to an inflammatory cascade resulting in ocular surface damage. No cure is available for DED, and patients require ongoing disease management. Over-the-counter medications can provide temporary symptom relief but do not tackle the inflammatory pathophysiology of DED. A number of medications with anti-inflammatory activity are available, but there is a need for development of pharmacotherapies with novel delivery methods and targets to widen the variety of treatment options. This review discusses current anti-inflammatory pharmacotherapies approved in the United States and Europe for DED and highlights novel drugs that have been recently approved or are in development.

Phase 3 Efficacy (Worse-Eye Analysis) and Long-Term Safety Evaluation of OTX-101 in Patients with Keratoconjunctivitis Sicca

Background

OTX-101 is approved for treatment of keratoconjunctivitis sicca (KCS). We present results of a phase 3 worse-eye efficacy analysis and 1-year safety extension.

Methods

During the double-masked treatment phase, patients with bilateral KCS were randomized 1:1 to 12 weeks OTX-101 or vehicle 1 drop per eye twice daily. Efficacy assessments included Schirmer’s test and corneal and conjunctival staining. All patients who completed the treatment phase were eligible for enrollment in the open-label extension and received 1 drop OTX-101 twice daily for up to 52 weeks. Safety endpoints included adverse event (AE) monitoring, Snellen visual acuity (VA), intraocular pressure (IOP), slit-lamp examination (SLE), and dilated fundoscopy.

Results

Overall, 745 and 258 patients enrolled in the treatment and safety extension phases, respectively. At 12 weeks, number (%) of patients with Schirmer’s score increase of ≥10 mm from baseline was 76 (20.5%) vs. 42 (11.3%) for OTX-101 vs. vehicle (P=0.0005). OTX-101 significantly improved total conjunctival staining vs. vehicle at week 12 (least squares mean change from baseline −1.65 [0.12] vs. −1.12 [0.12], P=0.0013), and number (%) of patients with clear central corneas vs. vehicle at week 12 (222 [64.0%] vs. 199 [55.3%], P=0.0179). In the 1-year safety extension, AEs were mostly mild; instillation site pain was most common in 59 (22.9%) patients (17 [13.2%] vs. 42 [32.6%] patients receiving prior OTX-101 and vehicle). No safety concerns were raised by VA, IOP, SLE, and fundoscopy.

Conclusion

OTX-101 efficacy was confirmed in the eye with lower baseline Schirmer’s score. OTX-101 was well tolerated long term.

Clinical Trial

Registered at ClinicalTrials.gov on July 27, 2016. NCT02845674 https://clinicaltrials.gov/ct2/show/NCT02845674?term=OTX-101&draw=2&rank=1.

A Review of the Mechanism of Action of Cyclosporine A: The Role of Cyclosporine A in Dry Eye Disease and Recent Formulation Developments

Dry eye disease (DED) is a multifactorial disease of the ocular surface and tear film that has gained awareness as a public health problem. Characteristics of DED include tear film instability, hyperosmolarity, and ocular surface inflammation, which can occur independently or may be a sequela of numerous ocular diseases, ocular surgery or contact lens wear. Much has been learned about the impact of the disease to help affected individuals who report symptoms of poor vision, pain, and tearing. Recently, new research highlights the importance of the role of ocular surface inflammation and damage in DED-leading to a vicious cycle of inflammation as well as loss of tear film homeostasis. DED immunopathophysiology is characterized by four stages: initiation, amplification, recruitment, and re-initiation. Cyclosporine is proven to be a valuable ophthalmic therapeutic for DED through its immunomodulatory actions and regulation of the adaptive immune response. Cyclosporine mechanism of action is well described in the published literature and the myriad of benefits in all four stages lend a broad-based immunomodulatory function particularly suitable for addressing DED. Furthermore, cyclosporine has unique goblet cell density improvement capabilities as well as anti-apoptotic properties. Topical formulations of cyclosporine are centered around addressing the highly lipophilic nature of the molecule. The poor aqueous solubility of cyclosporine traditionally presented technical challenges in drug delivery to the ocular surface. Newer formulations such as cationic emulsions and nanomicellar aqueous solutions address formulation, tissue concentration, and drug delivery challenges.

A review of the clinical applications of drug delivery systems for the treatment of ocular anterior segment inflammation

Ocular anterior segment inflammation is a medical problem that is seen in cases of cataract surgery and non-infectious anterior uveitis. Inadequately treated anterior segment inflammation can lead to sight-threatening conditions such as corneal oedema, glaucoma and cystoid macular oedema. The mainstay of treatment for anterior segment inflammation is topical steroid eye-drops. However, several drawbacks limit the critical value of this treatment, including low bioavailability, poor patient compliance, relatively difficult administration manner and risk of blurring of vision and ocular irritation. A drug delivery system (DDS) that can provide increased bioavailability and sustained delivery while being specifically targeted towards inflamed ocular tissue can potentially replace daily eye-drops as the gold standard for management of anterior segment inflammation. The various DDS for anti-inflammatory drugs for the treatment of anterior segment inflammation are listed and summarised in this review, with a focus on commercially available products and those in clinical trials. Dextenza, INVELTYS, Dexycu and Bromsite are examples of DDS that have enjoyed success in clinical trials leading to FDA approval. Nanoparticles and ocular iontophoresis form the next wave of DDS that have the potential to replace topical steroids eye-drops as the treatment of choice for anterior segment inflammation. With the current relentless pace of ophthalmic drug delivery research, the pursuit of a new standard of treatment that eliminates the problems of low bioavailability and patient compliance may soon be realised.

Prodrugs and nanomicelles to overcome ocular barriers for drug penetration

INTRODUCTION

Ocular barriers hinder drug delivery and reduce drug bioavailability. This article focuses on enhancing drug absorption across the corneal and conjunctival epithelium. Both, transporter targeted prodrug formulations and nanomicellar strategy is proven to enhance the drug permeation of therapeutic agents across various ocular barriers. These strategies can increase aqueous drug solubility and stability of many hydrophobic drugs for topical ophthalmic formulations.

AREAS COVERED

The article discusses various ocular barriers, ocular influx, and efflux transporters. It elaborates various prodrug strategies used for enhancing drug absorption. Along with this, the article also describes nanomicellar formulation, its characteristic and advantages, and applications in for anterior and posterior segment drug delivery.

EXPERT OPINION

Prodrugs and nanomicellar formulations provide an effective strategy for improving drug absorption and drug bioavailability across various ocular barriers. It will be exciting to see the efficacy of nanomicelles for treating back of the eye disorders after their topical application. This is considered as a holy grail of ocular drug delivery due to the dynamic and static ocular barriers, restricting posterior entry of topically applied drug formulations.

A Novel Eyes Topical Drug Delivery System: CsA-LNC for the Treatment of DED

PURPOSE

The objective of the present work was to prepare safe and effective Ciclosporin A Lipid nanocapsule (CsA-LNC) eye-drops for the treatment of DED.

METHODS

The phase-inversion method was used to prepared different sizes CsA-LNC. CsA biodistribution in ocular after topical administration in rabbits was analyzed by a validated UPLC-MS/MS method. The efficacy of CsA-LNCs (25 nm, 50 nm, 85 nm) was evaluated using the tear breakup time, fluorescein staining, tear production, inflammatory cytokines and histopathology tests. The safety of CsA-LNCs was study by the score of ocular irritation and histological examination study.

RESULTS

CsA-LNCs(20-100 nm) were successfully prepared, An in vivo PK study showed significant improvement of the bioavailability (4.20-fold (25 nm), 2.15-fold (50 nm) and 2.33-fold (85 nm)) in bulbar conjunctiva, and great permeability was observed in the cornea for CsA-LNCs compared with CsA emulsion. An in vivo PD study showed that CsA-LNCs have great efficacy for DED, and the effect was improved over CsA emulsion. CsA-LNCs were safe and not cause significant irritation to the eyes surface of rabbits.

CONCLUSION

This work has demonstrated CsA-LNCs, in particular small sizes CsA-LNC, are safe and effective with promising potential to treat DED. Grapical abstract.

Assembling Surfactants-Mucoadhesive Polymer Nanomicelles (ASMP-Nano) for Ocular Delivery of Cyclosporine-A

The physiological protective mechanisms of the eye reduce the bioavailability of topically administered drugs above all for those with high molecular weight and /or lipophilic characteristics, such as Cyclosporine A (CyA). The combined strategy based on the association of nanomicelles and mucoadhesive polymer seems promising since a limited number of commercial products containing CyA have been recently approved. The scope of this investigation was the design of Assembling Surfactants-Mucoadhesive Polymer Nanomicelles (ASMP-Nano), based on a binary system of two surfactants in combination with hyaluronic acid, and their biopharmaceutical evaluation. The optimisation of the ASMP-Nano in term of the amount of surfactants, CyA-loading and size determined the selection of the clear and stable Nano1HAB-CyA formulation containing 0.105% w/w CyA loaded-nanomicelles with a size of 14.41 nm. The nanostructured system had a protective effect towards epithelial corneal cells with a cell viability of more than 80%. It interacted with cellular barriers favouring the uptake and the accumulation of CyA into the cells as evidenced by fluorescent probe distribution, by hindering CyA permeation through reconstituted corneal epithelial tissue. In pharmacokinetics study on rabbits, the nanomicellar carrier prolonged the CyA retention time in the precorneal area mainly in presence of hyaluronic acid (HA), a mucoadhesive polymer.

A Review of Topical Cyclosporine A Formulations-A Disease-Modifying Agent for Keratoconjunctivitis Sicca

Keratoconjunctivitis sicca (KCS) is a multifactorial disease characterized by tear hyperosmolarity, inflammation, and ocular surface damage. Cyclosporine A (CsA) is used as an effective disease-modifying agent to improve the signs and symptoms of KCS by reducing inflammation, which interferes with tear production. This review provides an overview of efficacy, safety, and limitations of currently marketed topical CsA formulations—including CsA ophthalmic emulsion, cationic nanoemulsion, and aqueous nanomicelles—and highlights newer technologies for controlled ocular delivery of CsA and their clinical implications. Long available emulsion formulations of CsA are oil-based and have several limitations, including slow onset of efficacy and low intraocular penetration and bioavailability. Aqueous CsA nanomicelle carriers produce rapid improvement in objective signs of KCS such as corneal and conjunctival staining as early as 4 weeks and have acceptable safety profiles. CsA formulations using semifluorinated alkanes or polyaphrons are currently in clinical development, having recently completed Phase 2 studies. Other carriers for CsA currently in the preclinical phase include microemulsions, polymeric aqueous and lyophilized micelles, and hydrogels; these novel formulations have yet to undergo clinical trials. Formulations that improve tissue availability of CsA may be beneficial in clinical practice by providing faster onset of relief and improving patient adherence.

Aqueous deficiency is a contributor to evaporation-related dry eye disease

Dry eye disease aetiologies can be classified dichotomously into aqueous deficient and evaporative types although many cases involve combinations of both. Differential diagnosis can be confounded by some features of dry eye disease being common to both aetiologies. For example, short tear break-up times are prime diagnostic findings of tear instability due to lipid and/or mucin deficiencies, but thin tear layers in aqueous deficient eyes also shorten tear break-up times, even at normal range rates of evaporation in eyes without lipid and/or mucin deficiencies. Because tear instability and short tear film break-up times due to thin tear layers can be independent of lipid and/or mucin deficiency, aqueous deficiency can be another form of evaporation-related dry eye. Conversely, tear layers which are thickened by punctal occlusion can be less susceptible to tear break-up. An inflamed lacrimal gland producing reduced quantities of warmer tears can be a basis for thin tear layers and tear instability demonstrated by shorter tear break-up times. Commonly used clinical tests for aqueous deficiency can be unreliable and less sensitive. Consequently, failure to detect or confirm aqueous deficiency as a contributor to short tear break-up times could result in too much weight being given to a diagnosis of meibomian gland deficiency. Less successful treatment outcomes may be a consequence of failing to detect aqueous deficiency. Refining disease classification by considering aqueous deficiency as a contributor to, or even a form of evaporation-related dry eye, could be the basis for more comprehensive and appropriate treatment strategies. For example, some treatment methods for evaporation-related dry eye might be appropriate for aqueous and mucin-deficient as well as lipid-deficient dry eyes. Anti-inflammatory treatment for the lacrimal gland as well as the conjunctiva, may result in increased aqueous production, reduced tear temperature, tear instability and evaporation rates as well as lower osmolarity.