Ocular inserts based on chitosan and brimonidine tartrate: Development, characterization and biocompatibility

The glaucoma is an ocular pathology characterized by the increase of intraocular pressure and possibility of retinal degeneration. The treatment is based on the administration of eye drops. However, they do not induce the permanence of drug in the eye, compromising its bioavailability. In this study, inserts based on chitosan and brimonidine tartrate were developed to treat the glaucoma by improving the drug bioavailability. Inserts were characterized using different analytical techniques FTIR, SEM, DSC and WAXS. The in vitro release profile of drug from inserts was evaluated. The in vitro biocompatibility against ARPE-19 and MIO-M1 cells was investigated. The in vivo biocompatibility using the chorioallantoic membrane was also demonstrated. Analytical techniques demonstrated that the amorphous drug was physically dispersed into the polymeric chains without chemical interactions. However, a portion of drug crystals was on the surface of systems. Inserts provided the controlled release of drug for 30 days without a burst effect. Inserts did not induce a deleterious effect to ocular cells, indicating their biocompatibility. They were also well tolerated in vivo, suggesting the absence of toxicity. These inserts could be potential delivery systems to reduce the intraocular pressure and to induce neuroprotective effects in glaucomatous patients.