Browsing by Author "Alany, Raid G."

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    Approaches in topical ocular drug delivery and developments in the use of contact lenses as drug-delivery devices
    (Taylor and Francis, 2017-06-21) Mehta, P.; Haj-Ahmad, R.; Al-Kinani, Ali; Arshad, Muhammad Sohail; Chang, Ming-Wei; Alany, Raid G.; Ahmad, Z.
    Drug-delivery approaches have diversified over the last two decades with the emergence of nanotechnologies, smart polymeric systems and multimodal functionalities. The intended target for specific treatment of disease is the key defining developing parameter. One such area which has undergone significant advancements relates to ocular delivery. This has been expedited by the development of material advancement, mechanistic concepts and through the deployment of advanced process technologies. This review will focus on the developments within lens-based drug delivery while touching on conventional and current methods of topical ocular drug delivery. A summary table will provide quick reference to note the key findings in this area. In addition, the review also elucidates current theranostic and diagnostic approaches based on ocular lenses.
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    Assessing the ex vivo permeation behaviour of functionalised contact lens coatings engineered using an electrohydrodynamic technique
    (IOP Publishing, 2018-11-20) Ahmad, Z.; Alany, Raid G.; Amoaku, W. M.; Chang, Ming-Wei; Alqahtani, Ali; Arshad, Muhammad Sohail; Qutachi, Omar; Al-Kinani, Ali A.; Mehta, P.
    In vitro testing alone is no longer considered sufficient evidence presented solely with respect to drug release and permeation testing. These studies are thought to be more reliable and representative when using tissue or animal models; as opposed to synthetic membranes. The release of anti-glaucoma drug timolol from electrically atomised coatings was assessed here using freshly excised bovine corneal tissue. Electrohydrodynamic processing was utilised to engineer functionalised fibrous polyvinylpyrrolidone (PVP)-Poly (N-isopropylacrylamide) (PNIPAM) coatings or the outer side of commercial silicone contact lenses. Benzalkonium chloride (BAC), ethylenediaminetetraacetic acid (EDTA), Brij® 78 and borneol were employed as permeation enhancers to see their effect on ex vivo permeation of timolol maleate through the cornea. Formulations containing permeation enhancers showed a vast improvement with respect to cumulative amount of drug permeating through the cornea as shown by a 6 fold decrease in lag time compared to enhancer-free formulations. Most drug delivery systems require the drug to pass or permeate through a tissue or biological membrane. This study has shown that to fully appreciate and understand how a novel drug delivery system will behave not only within the device but with the external environment or tissue, it is imperative to have in vitro and ex vivo data in conjunction.
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    Development and characterisation of electrospun timolol maleate-loaded polymeric contact lens coatings containing various permeation enhancers
    (Elsevier, 2017-09-14) Mehta, P.; Al-Kinani, Ali A.; Arshad, Muhammad Sohail; Chang, Ming-Wei; Alany, Raid G.; Ahmad, Z.
    Despite exponential growth in research relating to sustained and controlled ocular drug delivery; anatomical and chemical barriers of the eye still pose formulation challenges. Nanotechnology integration into the pharmaceutical industry has aided efforts in potential ocular drug device development. Here, the integration and in vitro effect of four different permeation enhancers (PEs) on the release of anti-glaucoma drug timolol maleate (TM) from polymeric nanofiber formulations is explored. Electrohydrodynamic (EHD) engineering, more specifically electrospinning, was used to engineer nanofibers (NFs) which coated the exterior of contact lenses. Parameters used for engineering included flow rates ranging from 8 to 15 μL/min and a novel EHD deposition system was used; capable of hosting four lenses, masked template and a ground electrode to direct charged atomised structures. SEM analysis of the electrospun structures confirmed the presence of smooth nano-fibers; whilst thermal analysis confirmed the stability of all formulations. In vitro release studies demonstrated a triphasic release; initial burst release with two subsequent sustained release phases with most of the drug being released after 24 hours (86.7%) Biological evaluation studies confirmed the tolerability of all formulations tested with release kinetics modelling results showing drug release was via quasi-Fickian or Fickian diffusion. There were evident differences (p < 0.05) in TM release dependant on permeation enhancer.
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    Electrically atomised formulations of timolol maleate for direct and on-demand ocular lens coatings
    (Elsevier, 2017-06-15) Mehta, P.; Al-Kinani, Ali A.; Haj-Ahmad, R.; Arshad, Muhammad Sohail; Chang, Ming-Wei; Alany, Raid G.; Ahmad, Z.
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    Engineering and development of chitosan-based Nanocoatings for Ocular Contact Lenses
    (2018-12-01) Mehta, P.; Al-Kinani, Ali A.; Arshad, Muhammad Sohail; Singh, Neenu; van der Merwe, Susanna M.; Chang, Ming-Wei; Alany, Raid G.; Ahmad, Z.
    The research manuscript reports on Electrohydrodynamic Atomisation (EHDA) to engineer on-demand novel coatings for ocular contact lenses. A formulation approach was adopted to modulate the release of timolol maleate (TM) using chitosan and borneol. Polymers polyvinylpyrrolidone (PVP) and poly (N-isopropylacrylamide) (PNIPAM) were utilised to encapsulate TM and were electrically atomised to produce optimised, stationary contact lens coatings. The particle and fibre diameter, thermal stability, material compatibility of the formed coatings along with their in vitro release-modulating effect and ocular tolerability were investigated. The results demonstrated highly stable nano-matrices with advantageous morphology and size. All formulations yielded coatings with high TM encapsulation (>88%); with excellent ocular biocompatibility. The coatings presented biphasic and triphasic release profiles; depending on composition. Kinetic modelling revealed a noticeable effect of chitosan; the higher the concentration, the more the release of TM due to chitosan swelling; with the release mechanism changing from Fickian diffusion (1% w/v; n = 0.5) to non-Fickian (5% w/v, 0.45 < n < 0.89). The use of EHDA has not yet been explored in depth within the ocular research remit; engineering on demand lens coatings capable of sustaining TM release. This is likely to offer an alternative dosage form for management of glaucoma with particular emphasis on improving poor patient compliance.