title: An in vitro study of the design and development of a novel doughnut-shaped minitablet for intraocular implantation.
abstract: A novel doughnut-shaped minitablet (DSMT) was developed and evaluated as a biodegradable intraocular drug delivery system for rate-modulated delivery of antiviral bioactives. The DSMT device was manufactured using a special set of punches fitted with a central-rod in a Manesty tableting press. The DSMT device released the antiretrovirals foscarnet and ganciclovir at a first-order rate. The erosion kinetics was assessed by gravimetric analysis and scanning electron microscopy. The device gradually eroded when immersed in simulated vitreous humor (SVH) (pH 7.4, 37 degrees C) and released bioactives in a sustained manner. The novel geometric design and veracity of the DSMT device was retained even after 24 weeks of erosion. When considering the duration of the bioactive released from the DSMT device, it was found that by the careful selection of the type and concentration of polymer employed in formulating the DSMT device, it was possible to produce a device that could release drug for any period up to 12 months.
authors.affiliation: Department of Pharmacy and Pharmacology, University of the Witwatersrand, 7 York Road, Parktown 2193, Johannesburg, Gauteng, South Africa.
authors.forename: Yahya E
authors.initials: YE
authors.lastname: Choonara
authors.forename: Viness
authors.initials: V
authors.lastname: Pillay
authors.forename: Trevor
authors.initials: T
authors.lastname: Carmichael
authors.forename: Michael P
authors.initials: MP
authors.lastname: Danckwerts
mesh_terms: D044966:Anti-Retroviral Agents / Q000737:chemistry / Q000378:metabolism; D001082:Aqueous Humor / Q000737:chemistry / Q000378:metabolism; D004337:Drug Carriers / Q000737:chemistry / Q000378:metabolism; D004343:Drug Implants; D005123:Eye / Q000737:chemistry / Q000378:metabolism; D017245:Foscarnet / Q000737:chemistry / Q000378:metabolism; D015774:Ganciclovir / Q000737:chemistry / Q000378:metabolism; D006244:Hardness; D006801:Humans; D066298:In Vitro Techniques; D019344:Lactic Acid / Q000737:chemistry; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000737:chemistry; D012995:Solubility; D013607:Tablets / Q000737:chemistry; D014783:Viscosity
chemical_list: D044966:Anti-Retroviral Agents; D004337:Drug Carriers; D004343:Drug Implants; D011108:Polymers; D013607:Tablets; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D017245:Foscarnet; D015774:Ganciclovir