title: Preformulation of cysteamine gels for treatment of the ophthalmic complications in cystinosis.
abstract: Nephropathic cystinosis is a rare autosomal recessive disease characterised by raised lysosomal levels of cystine in the cells of all organs. It is treated by regular administration of the aminothiol, cysteamine. Corneal crystal deposition is one of the most troublesome complications affecting patients and requires the hourly administration of cysteamine eye drops. In an attempt to reduce this frequency and improve the treatment, the preformulation and evaluation of cysteamine containing gels is reported. Suitability for ophthalmic delivery was determined by analysis of rheology, bioadhesion, dissolution and stability. The results demonstrated that three polymers were suitable for ophthalmic delivery of cysteamine; namely sodium hyaluronate, hydroxyethyl cellulose and carbomer 934. Sodium hyaluronate displayed optimum performance in the preformulation tests, being pseudoplastic (reduction in apparent viscosity under increasing shear rate), bioadhesive, releasing cysteamine over 40min and displaying stability over time. In conclusion these results offer the possibility to formulate cysteamine in an ocular applicable gel formulation.
authors: School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen, AB10 7GJ, UK. Electronic address: b.mckenzie1@rgu.ac.uk.
authors: Barbara
authors: B
authors: McKenzie
authors: School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen, AB10 7GJ, UK.
authors: Graeme
authors: G
authors: Kay
authors: School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen, AB10 7GJ, UK.
authors: Kerr H
authors: KH
authors: Matthews
authors: School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen, AB10 7GJ, UK.
authors: Rachel
authors: R
authors: Knott
authors: School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen, AB10 7GJ, UK.
authors: Donald
authors: D
authors: Cairns
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D000818:Animals; D002417:Cattle; D002482:Cellulose / Q000031:analogs & derivatives / Q000737:chemistry; D002626:Chemistry, Pharmaceutical / Q000379:methods; D003315:Cornea / Q000187:drug effects*; D003543:Cysteamine / Q000737:chemistry* / Q000494:pharmacology*; D003554:Cystinosis / Q000150:complications; D016503:Drug Delivery Systems / Q000379:methods; D005128:Eye Diseases / Q000188:drug therapy* / Q000209:etiology; D005782:Gels / Q000737:chemistry* / Q000494:pharmacology*; D006801:Humans; D006820:Hyaluronic Acid / Q000737:chemistry; D009883:Ophthalmic Solutions / Q000737:chemistry / Q000494:pharmacology; D011108:Polymers / Q000737:chemistry; D012212:Rheology; D012995:Solubility
chemical_list: D000180:Acrylic Resins; D005782:Gels; D009883:Ophthalmic Solutions; D011108:Polymers; C006903:carbopol 940; D003543:Cysteamine; D002482:Cellulose; D006820:Hyaluronic Acid; C002283:hydroxyethylcellulose
keywords: Cysteamine; Cystinosis; Gel; Ophthalmic delivery; Preformulation