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Nanomedicines for Ocular NSAIDs: State-of-the-Art Update of the Safety on Drug Delivery
Published in Lajos P. Balogh, Nano-Enabled Medical Applications, 2020
Joana R. Campos, Joana Araújo, Elisabet Gonzalez-Mira, Maria A. Egea, Elena Sanchez-Lopez, Marta Espina, Selma B. Souto, Maria L. Garcia, Eliana B. Souto
Many authors have tested the use of microparticles as drug carriers over the last decades. Posterior segment diseases such as proliferative vitreoretinopathy, age-related macular degeneration, diabetic retinopathy, uveitis, macular oedema, cytomegalovirus, glaucoma, and retinitis pigmentosa have been treated with drug-loaded microspheres with a relatively high rate of success [199]. Addo et al. observed that the use of tetracaine-loaded microparticles enhanced the anaesthetic effect of the drug in rabbits, in comparison with a commercialized ophthalmic solution [200]. Other authors have studied the hypothesis that mucoadhesive microparticles may offer a means for slow drug release from the particles that remain adherent to the ocular surface for an extended period of time. Sensoy et al. showed the utility of mucoadhesive polymers for the preparation of bioadhesive microspheres loaded with sulphacetamide for the treatment of keratitis in rabbits [201]. Choy et al. observed that the use of a mucoadhesion promoter such as polyethyleneglycol (PEG) increased the microparticles’ retention time on the ocular surface of rabbits [202, 203].
Ocular Drug Delivery Systems
Published in Ambikanandan Misra, Aliasgar Shahiwala, In-Vitro and In-Vivo Tools in Drug Delivery Research for Optimum Clinical Outcomes, 2018
Shubhini A. Saraf, Jovita Kanoujia, Samipta Singh, Shailendra K. Saraf
Proliferative vitreoretinopathy is a severe eye injury or a complication of retinal detachment. This model is based on the principle that if the cultured fibroblast cells are cultured into the rabbit’s vitreous region, they might mimic the condition of proliferative vitreoratinopathy in them. The explants obtained from the dorsal skin of rabbit, after removing hair and subcutaneous fat, are rinsed, finely minced, and placed in petri dishes containing Dulbecco’s medium supplemented with heat-inactivated fetal calf serum, garamycin, and fungizone. When the cells started growing, the pieces of tissue and the medium are removed and 2 ml of fresh medium is added. After the cells are grown to convergence, they are passaged into flasks by rinsing with PBS and incubating in trypsin/EDTA. Subsequent to the initial passage, cells are split in a ratio of 1:4 upon reaching confluence. For injection purpose, cells from third to tenth passage are trypsinized using trypsin/EDTA, centrifuged, washed, and re-suspended in a medium and permitted to stand for some time till cell clumps are settled. The number of cells is determined using a Coulter counter.
Therapeutic challenges in ocular delivery of lipid based emulsion
Published in Egyptian Journal of Basic and Applied Sciences, 2018
Rahul Tiwari, Vikas Pandey, Saket Asati, Vandana Soni, Dharmendra Jain
Ophthalmic drug delivery is one of the foremost challenging endeavors in the research and development of novel drug formulation due to the unique structure of the eye along with the physiology and biochemistry which restrict the free entry of the drug molecules leading to poor BA [1]. Hence, it would be essential to design and develop a formulation which can enhance drug target ability, prolong the drug residence time at ocular surface and reduce the administration frequency [2]. The main problem associated with ocular drug delivery is to maintain an optimum drug concentration at the site of action for therapeutic response and to attain the predictable pharmacological response. The said problem can be resolve by exploiting the particulate novel drug delivery systems, providing exciting opportunities for ocular drug delivery [3]. These carriers have the ability to safeguard the encapsulated substances and help in the transportation to various compartments of the eye [4]. Various extra and intra-ocular diseases such as glaucoma, keratitis uveitis, acute retinal necrosis, dry eye syndromes, cytomegalovirus retinitis, macular degenerative disease, proliferative vitreoretinopathy, etc., can be treated by the traditional drug delivery system such as eye drops containing lipophilic and poorly water soluble drugs [5]. Topical delivery into the lower cul-de-sac of eye using eye drops is the most recognizable method for the treatment of ocular diseases [6]. But these traditional delivery systems are not only causing discomfort to the patient, but also not able to treat efficiently or fight with the serious ocular diseases [7]. The target site for most of the ophthalmic drugs is the anterior segment of eye, while external eye structures are readily accessible. The biological barriers, conjunctiva, corneal epithelium also limits the ocular drug absorption [8]. In recent years, LEs have emerged as promising platform in ocular drug delivery in term of improved BA. The emulsions increases the BA by two main approaches i.e., (a) either by enhances the corneal permeability or (b) by increasing the retention time of the formulation in the ocular surface. Primarily, LEs are used for parenteral applications to achieve fast pharmacological action recently they are developing as a vehicle to enhance the ocular BA of lipophilic drugs [9].