Charged nanoparticles delivery to the eye using hydrogel iontophoresis.
ABSTRACT Ocular iontophoresis has been investigated for many years as a non-invasive technique for enhancing ionized drug penetration through ocular tissues. In this study we assessed the penetration of charged fluorescent nanoparticles into rabbit eyes using hydrogel iontophoresis. Particle distribution into ocular tissues and penetration efficiency of negative nanoparticles compared with positive nanoparticles was also evaluated. Cathodal and anodal iontophoretic administrations were performed using polyacrylic hydrogels loaded with charged nanoparticle suspension (20-45 nm), applying a current intensity of 1.5 mA for 5 min onto the cornea and sclera. At pre-set time points post treatment, eyes were dissected and tissues were evaluated for fluorescence intensity. Strong fluorescence evidence was observed at anterior and posterior ocular tissues. Negative particle distribution profile revealed fast uptake into the outer ocular tissues, within 30 min post treatment, followed by particle migration into the inner tissues up to 12 h post treatment. The positively charged particles demonstrated better penetration abilities into inner ocular tissues compared to the negatively charge particles. This work provides an opening for the development of a new ocular therapeutic pathway using iontophoresis of extended release drug-loaded charged nanoparticles.
- Journal of controlled release : official journal of the Controlled Release Society. 05/2014;
- [Show abstract] [Hide abstract]
ABSTRACT: The basic concepts, major mechanisms, technological developments and advantages of the topical application of lipid-based systems (microemulsions, nanoemulsions, liposomes and solid lipid nanoparticles), polymeric systems (hydrogels, contact lenses, polymeric nanoparticles and dendrimers) and physical methods (iontophoresis and sonophoresis) will be reviewed. Although very convenient for patients, topical administration of conventional drug formulations for the treatment of eye diseases requires high drug doses, frequent administration and rarely provides high drug bioavailability. Thus, strategies to improve the efficacy of topical treatments have been extensively investigated. In general, the majority of the successful delivery systems are present on the ocular surface over an extended period of time, and these systems typically improve drug bioavailability in the anterior chamber whereas the physical methods facilitate drug penetration over a very short period of time through ocular barriers, such as the cornea and sclera. Although in the early stages, the combination of these delivery systems with physical methods would appear to be a promising tool to decrease the dose and frequency of administration; thereby, patient compliance and treatment efficacy will be improved.The Journal of pharmacy and pharmacology. 04/2014; 66(4):507-30.
Article: Ocular delivery of macromolecules.[Show abstract] [Hide abstract]
ABSTRACT: Biopharmaceuticals are making increasing impact on medicine, including treatment of indications in the eye. Macromolecular drugs are typically given by physician---administered invasive delivery methods, because non---invasive ocular delivery methods, such as eye drops, and systemic delivery, have low bioavailability and/or poor ocular targeting. There is a need to improve delivery of biopharmaceuticals to enable less---invasive delivery routes, less---frequent dosing through controlled--- release drug delivery and improved drug targeting within the eye to increase efficacy and reduce side effects. This review discusses the barriers to drug delivery via various ophthalmic routes of administration in the context of macromolecule delivery and discusses efforts to develop controlled--- release systems for delivery of biopharmaceuticals to the eye. The growing number of macromolecular therapies in the eye needs improved drug delivery methods that increase drug efficacy, safety and patient compliance.Journal of controlled release : official journal of the Controlled Release Society. 07/2014;