ABSTRACT
The objective of this study was to develop and characterize a biodegradable drug-loaded nerve guide for peripheral nerve regeneration. Sabeluzole, a nerve growth agent, was selected as model compound. Four biodegradable polymers were selected for this study: a copolymer of polylactic acid and polycaprolactone (PCL); a copolymer of polyglycolic acid and polycaprolactone PCL; a copolymer of PCL/polydioxanone (PDO) and PDO. Placebo and drug loaded nerve guides were obtained by melt compression and melt extrusion. It was observed that melt compression and melt extrusion are feasible techniques to prepare the nerve guides. Based on the physicochemical characterization, all samples show absence of crystalline sabeluzole, indicating the formation of an amorphous dispersion. The in vitro release measurements show that the release of sabeluzole is complete, reproducible and can be controlled by the proper selection of the polymer. The release mechanism for all samples follows Fickian release behaviour.
Subject(s)
Absorbable Implants , Body Fluids/chemistry , Drug Implants/chemistry , Lactic Acid/chemistry , Piperidines/administration & dosage , Piperidines/chemistry , Polyesters/chemistry , Polymers/chemistry , Thiazoles/administration & dosage , Thiazoles/chemistry , Animals , Biocompatible Materials , Diffusion , Drug Stability , Equipment Failure Analysis , Humans , Materials Testing , Nerve Growth Factors/administration & dosage , Nerve Growth Factors/chemistry , Nerve Regeneration/drug effects , Peripheral Nerve Injuries , Peripheral Nerves/drug effects , Peripheral Nerves/surgery , Prosthesis Design , TemperatureABSTRACT
Electrostatic spinning was applied to the preparation of drug-laden nonbiodegradable nanofiber for potential use in topical drug administration and wound healing. The specific aim of these studies was to assess whether these systems might be of interest as delivery systems for poorly water-soluble drugs. Itraconazole and ketanserin were selected as model compounds while a segmented polyurethane (PU) was selected as the nonbiodegradable polymer. For both itraconazole and ketanserin, an amorphous nanodispersion with PU was obtained when the drug/polymer solutions were electrospun from dimethylformide (DMF) and dimethylacetamide (DMAc), respectively. The collected nonwoven fabrics were shown to release the drugs at various rates and profiles based on the nanofiber morphology and drug content. Data were generated using a specially designed release apparatus based around a rotating cylinder. At low drug loading, itraconazole was released from the nanofibers as a linear function of the square root of time suggesting Fickian kinetics. No initial drug burst was observed. A biphasic release pattern was observed for ketanserin in which two sequential linear components were noted. These release phases may be temporally correlated with (1) drug diffusion through the polymer and (2) drug diffusion through formed aqueous pores.
Subject(s)
Drug Carriers/chemistry , Drug Delivery Systems/methods , Nanotechnology/methods , Polymers/chemistry , Polyurethanes/chemistry , Calorimetry, Differential Scanning , Delayed-Action Preparations/chemistry , Itraconazole/administration & dosage , Itraconazole/pharmacokinetics , Ketanserin/administration & dosage , Ketanserin/pharmacokinetics , Kinetics , Microscopy, Electron, Scanning , Molecular Structure , Phase Transition , Static ElectricityABSTRACT
PURPOSE: We assessed the application of water-soluble polymer-based nanofibers prepared by electrostatic spinning as a means of altering the dissolution rate of the poorly water-soluble drug, itraconazole. METHODS: Organic solvent-based solutions of itraconazole/HPMC mixtures were electrostatically spun at 16 and 24 kV. The formed nanofibers were collected as a non-woven fabric. The samples were analyzed by scanning electron microscopy. differential scanning calorimetry, and dissolution rate. RESULTS: Scanning electron microscopy showed fiber diameters of 1-4 microm and 300-500 nm depending on the applied voltage. Differential scanning calorimetry measurements found that the melting endotherm for itraconazole was not present, suggesting the formation of an amorphous solid dispersion or solution. Dissolution studies assessed several presentations including direct addition of the non-woven fabrics to the dissolution vessels, folding weighed samples of the materials into hard gelatin capsules and placing folded material into a sinker. Controls included a physical mixture as well as solvent cast and melt extruded samples. Electrospun samples dissolved completely over time with the rate of dissolution depending on the formulation presentation and drug to polymer ratio. The physical mixture did not appreciably dissolve in these conditions. CONCLUSIONS: The application of electrostatic spinning to pharmaceutical applications resulted in dosage forms with useful and controllable dissolution properties.