In vitro drug release and in vivo safety of vitamin E and cysteamine loaded contact lenses

Dixon, Phillip; Fentzke, Richard C.; Bhattacharya, Aniruddha; Konar, Aditya; Hazra, Sarbani; Chauhan, Anuj

doi:10.1016/j.ijpharm.2017.11.059

Cited by 42 publications

(17 citation statements)

References 30 publications

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“…Several early preclinical studies have investigated the feasibility of cysteamine-preloaded contact lenses for ocular cystinosis, predominantly to reduce dosing frequency. In two separate studies, commercially available contact lenses were preloaded with 50 mg/ml cysteamine and vitamin E, which prolongs the release of other ocular drugs and also retards cysteamine oxidation [ 50 , 51 ]. Silicone hydrogel contact lenses demonstrated a favourable duration of drug elution, which equated to exposure for 4–5 h daily to deliver an effective dose of cysteamine.…”

Section: Discussionmentioning

confidence: 99%

Latest Clinical Approaches in the Ocular Management of Cystinosis: A Review of Current Practice and Opinion from the Ophthalmology Cystinosis Forum

et al. 2018

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Cystinosis, a rare autosomal recessive disease caused by intracellular cystine accumulation, occurs in an estimated 1/100,000–200,000 live births. Ocular non-nephropathic cystinosis is typically diagnosed during adulthood, when patients present with corneal crystal deposition and no systemic involvement. Due to the rarity of the condition, diagnosis is often delayed and can have a significant impact on the overall prognosis of the disease. Early diagnosis is therefore imperative to ensure successful treatment and improve quality of life, as most of its clinical manifestations can be prevented or delayed. Early detection strategies and practical approaches for the ocular management of cystinosis were discussed during the Ophthalmology Cystinosis Forum, a 1-day meeting held in Berlin, Germany during June 2017. Recommendations for early detection comprise ophthalmic assessment, including self- and clinician-assessed recording of photophobia, and visual acuity, slit-lamp examination and tonometry ophthalmic examinations. In vivo confocal microscopy and anterior segment optical coherence tomography were highlighted as valuable techniques in evaluating cystine crystals in the cornea, in vivo and non-invasively. The mainstay of ocular cystinosis treatment is the cystine-depleting aminothiol cysteamine. Indeed, early treatment with and strict adherence to cysteamine therapy has a considerable impact on the long-term prognosis of ocular cystinosis. In rare diseases such as ocular cystinosis, standardised guidelines and recommendations for detection, patient care and follow-up assessments are essential. Such guidelines provide a support tool for healthcare professionals caring for ocular cystinosis patients. Multidisciplinary teams (MDTs) are essential for delivering gold standard care and improving quality of life for patients and their families. This review paper highlights current early detection policies, clinical treatment strategies and practical approaches for the ocular management of cystinosis, including implementing a cystinosis MDT. Additionally, discussions of the Ophthalmology Cystinosis Forum held in 2017 are summarised.FundingOrphan Europe.Plain Language SummaryPlain language summary available for this article.

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Section: Discussionmentioning

confidence: 99%

Latest Clinical Approaches in the Ocular Management of Cystinosis: A Review of Current Practice and Opinion from the Ophthalmology Cystinosis Forum

et al. 2018

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“…Whilst topical cysteamine remains the main modality of treatment for corneal crystals associated with cystinosis, other therapeutic options may become available in future, including the use of contact lenses impregnated with cysteamine [38] and nanowafers [39] both of which can be placed directly on the cornea and release a sustained and prolonged delivery of the cysteamine to the cornea. Human trials of these modalities are awaited to assess efficacy and acceptability.…”

Section: Discussionmentioning

confidence: 99%

The Ocular Status of Cystinosis Patients Receiving a Hospital Pharmacy-Made Preparation of Cysteamine Eye Drops: A Case Series

Biswas

Sornalingam

2018

Ophthalmol Ther

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Introduction Infantile nephropathic cystinosis (INC) is an autosomal recessive lysosomal disorder in which patients develop deposits of cystine crystals in their kidneys and corneas from a young age. Methods We conducted a retrospective analysis of children with INC seen by ophthalmologists at the Manchester Royal Eye Hospital between 2002 and 2018, to evaluate clinical findings, symptoms and treatment. Results Twenty-two children diagnosed with INC from age 0 (prenatally) to 11 years were assessed. All evaluable patients had corneal cystine crystal deposits, and 15 had mild to moderate photophobia. Ten patients had other ocular conditions including blepharitis/chalzion ( n = 6), swollen optic nerve ( n = 3), punctate epitheliopathy ( n = 3), corneal scarring ( n = 1),and elevated intraocular pressure ( n = 2). Confocal imaging identified nerve abnormalities in two patients (enlarged corneal nerve + abnormal-looking tortuous nerves in one patient and beaded nerves in the sub-basal plexus in the other), both of whom had significant crystal deposition in the anterior stroma. Visual acuity was relatively unaffected. All 22 patients were receiving oral cysteamine, and 21 were applying cysteamine eye drops (galenic preparation of 0.55% concentration, compounded by a hospital pharmacy). Recommended application frequency was at least eight times per day in all patients with dosing information available. Conclusions This case series of patients with INC highlights the consistent pattern of corneal cystine crystal deposition, which is universally present from a young age in this condition, and the high incidence of photophobia even in young children. Corneal manifestations of INC persisted despite frequent administration of the hospital pharmacy-made eye drop preparation. Reasons for this lack of efficacy may include the lag period between diagnosis and first prescription of cysteamine eye drops and the difficulty in maintaining rigorous compliance with this treatment. In addition, the challenge for patients of maintaining optimal storage conditions may adversely affect the stability and efficacy of cysteamine within this preparation. Funding Editorial assistance was funded by Orphan Europe Ltd.

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“…In another experiment by Kim et al, vitamin E was easily incorporated into commercial silicone-hydrogel lenses such as ACUVUE ® , OASYS™, O 2 OPTIX™, and NIGHT&DAY™ [184]. Some of the delivered drugs included cysteamine [186,187] and pirfenidone [188]. Typically, vitamin E was incorporated into the hydrogel through soaking, and the hydrophobic character means it is unlikely to leech out, compared with a hydrophilic component such as PVA.…”

Section: Outlook For CL Materialsmentioning

confidence: 99%

Contact Lens Materials: A Materials Science Perspective

2019

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More is demanded from ophthalmic treatments using contact lenses, which are currently used by over 125 million people around the world. Improving the material of contact lenses (CLs) is a now rapidly evolving discipline. These materials are developing alongside the advances made in related biomaterials for applications such as drug delivery. Contact lens materials are typically based on polymer- or silicone-hydrogel, with additional manufacturing technologies employed to produce the final lens. These processes are simply not enough to meet the increasing demands from CLs and the ever-increasing number of contact lens (CL) users. This review provides an advanced perspective on contact lens materials, with an emphasis on materials science employed in developing new CLs. The future trends for CL materials are to graft, incapsulate, or modify the classic CL material structure to provide new or improved functionality. In this paper, we discuss some of the fundamental material properties, present an outlook from related emerging biomaterials, and provide viewpoints of precision manufacturing in CL development.

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In vitro drug release and in vivo safety of vitamin E and cysteamine loaded contact lenses

Cited by 42 publications

References 30 publications

Latest Clinical Approaches in the Ocular Management of Cystinosis: A Review of Current Practice and Opinion from the Ophthalmology Cystinosis Forum

Latest Clinical Approaches in the Ocular Management of Cystinosis: A Review of Current Practice and Opinion from the Ophthalmology Cystinosis Forum

The Ocular Status of Cystinosis Patients Receiving a Hospital Pharmacy-Made Preparation of Cysteamine Eye Drops: A Case Series

Contact Lens Materials: A Materials Science Perspective

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