Drug delivery through soft contact lenses: An introduction

Jha, Gourishanker; Kumar, Amit

doi:10.4103/2229-5186.79342

Cited by 18 publications

(10 citation statements)

References 2 publications

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“…Drug-loaded soft hydrogel contact lenses are an attractive and convenient ocular drug delivery approach. Consisting of a three-dimensional polymer network, contact lenses possess the ability to absorb drug solutions and retain them in their hydrogel matrix . By attaching to the tear film over the cornea, they increase the ocular residence time of the incorporated medication and, thus, allow greater opportunity for drug release and instillation .…”

Section: Introductionmentioning

confidence: 99%

In Vitro Topical Delivery of Chlorhexidine to the Cornea: Enhancement Using Drug-Loaded Contact Lenses and β-Cyclodextrin Complexation, and the Importance of Simulating Tear Irrigation

et al. 2020

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Microbial keratitis is a severe, sight threatening condition caused by various pathogens. Eyedrops are the standard delivery modality for treating these disorders; however, blinking reflex, elevated tear production and nasolacrimal drainage eliminate much of the instilled dose within a few seconds. Therefore, eye drops must be applied repeatedly for prolonged periods. The present study aimed to probe more effective ocular delivery of chlorhexidine based upon drug-loaded hydrogel contact lenses and β-cyclodextrin (β-CD), whilst also determining the effect of constant irrigation with simulated tear fluid (STF) in in vitro experiments. Chlorhexidine digluconate (as 0.2 and 2.0% solution, β-CD inclusion complexes and loaded hydrogel contact lenses) were applied to enucleated porcine eyes as single or multiple 10 µL doses, or as drug-loaded contact lenses, with and without β-CD. The corneas were then excised and drug extracted quantified by HPLC. The effect of constant irrigation by STF was evaluated to test the effect of increased tear production on corneal delivery. Potential antimicrobial activity of delivered drug was also assessed. Results showed that drug-loaded contact lenses delivered the greatest amount of chlorhexidine into the cornea over a 24 h period, whilst the eyedrop solution comparator delivered the least. The β-CD significantly enhanced chlorhexidine delivery to the cornea from eyedrop solution, although contact lenses loaded with chlorhexidine-β-CD failed to enhance delivery. β-CD within the hydrogel matrix impeded drug release. Constant irrigation with STF significantly reduced the amount of drug delivered to the cornea in all cases. Chlorhexidine retained antimicrobial activity in all delivery methods. Hydrogel contact lenses loaded with chlorhexidine delivered significantly higher levels to the cornea compared to eyedrops, either multiple hourly doses or a single dose. They also offer reduced application, in particular to a non-ulcerated corneal infection. Finally, the importance of fully accounting for tear production in in vitro ocular delivery experiments was highlighted.

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Section: Introductionmentioning

confidence: 99%

In Vitro Topical Delivery of Chlorhexidine to the Cornea: Enhancement Using Drug-Loaded Contact Lenses and β-Cyclodextrin Complexation, and the Importance of Simulating Tear Irrigation

et al. 2020

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Section: Medicated Contact Lensesmentioning

confidence: 99%

“…With further development, strategies to sustain the drugs were introduced extending the drug delivery over a longer period of time. Incorporation of drug molecules in nanoparticles, micro emulsions, and cyclodextrins were used to fulfil this character of the lens [56,58,59]. However, regulatory agencies have not issued a profound regulation that would categorise medicated contact lenses although they are already working on this [60].…”

Section: Medicated Contact Lensesmentioning

confidence: 99%

Untitled

2017

PPIJ

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Objectives: The continuous interest surrounding the utilisation of contact lens for various purposes such as vision correction, cosmetics, and ocular drug delivery has led to more innovations to maximise its potential into more novel applications. Contact lens serving as a polymer matrix vehicle may be an effective system in releasing drugs at a desired rate and duration, proving supreme over conventional methods. Although studies are continuously conducted to gather evidence of its potential and effectiveness, there are various hurdles preventing availability to the public. Methods:This review surveys the current and potential applications of contact lenses with emphasis on in vivo studies, clinical trials and current regulations. Key findings:The number of contact lenses' wearers has gradually increased overtime. With the continuous research advancement, there is a high hope for contact lenses to be used as an ocular drug delivery system and could potentially provide a great platform for managing conditions such as glaucoma, allergy and photosensitivity. Moreover, the use of smart contact lenses in managing nonocular conditions like diabetes demonstrates its endless possibilities. Conclusion:Side effects associated with frequent using of contact lenses and current regulations by governing bodies are amongst the challenges for the emerging new applications. Keywords: Contact Lenses: Clinical Evaluation, Associated Challenges and Perspectives 2/13Copyright: ©2017 Mosuela et al. CorrectiveContact lens, in terms of correcting vision, functions the same way as conventional eyeglasses [12]. There are, however, different types of contact lenses to correct different vision problems including myopia (near-sightedness), hyperopia (farsightedness), and astigmatism (both near and far-sightedness [13]. MyopiaMyopia is one of the prevailing causes of reduced vision throughout the world. In simple terms, myopia or nearsightedness is the blurred vision to far away objects. According to the British Contact Lens Association (BCLA), myopia develops during the early ages of a growing adult, usually from 6 to 8 years of age although the onset of progression varies [14]. Theoretically, myopia is a result of changes concerning the length of eyeball [15]. When the eyeball is affected by the change in shape of the cornea for prolonged periods, this causes the light rays to focus at a point in front of the retina rather than on its surface directly. Diagnosis and treatment of myopia involve the expertise of an eye specialist to provide best method of treatment. Eyeglasses are the simplest way to correct this vision problem. However, contact lens gives more benefits, mainly comfort and clearer vision along with a more cosmetic appeal [16]. The main types of recommended lenses are gas permeable, soft, bifocal, multi focal and orthokeratology [14]. However, the use of these methods to correct vision issues was not enough for long term management resulting in a probable reoccurrence of myopia. Hence, different studies have been co...

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“…Incorporation of drug molecules in nanoparticles, micro emulsions, and cyclodextrins were used to fulfil this character of the lens. 56,58,59 However, regulatory agencies have not issued a profound regulation that would categorise medicated contact lenses although they are already working on this. 60 It is also worth emphasising those contact lenses as a platform for ocular drug delivery is still being continuously studied up to present time.…”

Section: Medicated Contact Lensesmentioning

confidence: 99%

“…Medicated contact lenses, also termed as "smart" contact lenses came into the picture when conventional ophthalmic drug delivery systems such as eye drops and ointments release drugs uncontrollably and 95% of the drug is lost either into the tear drainage or absorption in the conjunctiva. 56,57 The incorporation of drugs into contact lenses has faced many challenges before reaching a successful stage. One of obstacles was the rapid drug release and inability to sustain the drug particles into the polymer matrix hence; the contact lenses could only be used over a very short period of time.…”

Section: Medicated Contact Lensesmentioning

confidence: 99%