Cyclosporine A delivery to the eye: a pharmaceutical challenge.

Systemic administration of cyclosporine A (CsA) is commonly used in the treatment of local ophthalmic conditions involving cytokines, such as corneal graft rejection, autoimmune uveitis and dry eye syndrome. Local administration is expected to avoid the various side effects associated with systemic delivery. However, the currently available systems using oils to deliver CsA topically are poorly tolerated and provide a low bioavailability. These difficulties may be overcome through formulations aimed at improving CsA water solubility (e.g. cyclodextrins), or those designed to facilitate tissue drug penetration using penetration enhancers. The use of colloidal carriers (micelles, emulsions, liposomes and nanoparticles) as well as the approach using hydrosoluble prodrugs of CsA have shown promising results. Solid devices such as shields and particles of collagen have been investigated to enhance retention time on the eye surface. Some of these topical formulations have shown efficacy in the treatment of extraocular diseases but were inefficient at reaching intraocular targets. Microspheres, implants and liposomes have been developed to be directly administered subconjunctivally or intravitreally in order to enhance CsA concentration in the vitreous. Although progress has been made, there is still room for improvement in CsA ocular application, as none of these formulations is ideal.

Monday Morning Eye Opener, March 7, 2016

Weekly Newsletter from the Northwest District Office for libraries containing programs, activities, classes for the upcoming week.

Monday Morning Eye Opener, March 14, 2016

Weekly Newsletter from the Northwest District Office for libraries containing programs, activities, classes for the upcoming week.

Monday Morning Eye Opener, March 21, 2016

Weekly Newsletter from the Northwest District Office for libraries containing programs, activities, classes for the upcoming week.

Monday Morning Eye Opener, March 28, 2016

Weekly Newsletter from the Northwest District Office for libraries containing programs, activities, classes for the upcoming week.

Monday Morning Eye Opener, April 4, 2016

Weekly Newsletter from the Northwest District Office for libraries containing programs, activities, classes for the upcoming week.

Monday Morning Eye Opener, April 11, 2016

Weekly Newsletter from the Northwest District Office for libraries containing programs, activities, classes for the upcoming week.

Monday Morning Eye Opener, April 18, 2016

Weekly Newsletter from the Northwest District Office for libraries containing programs, activities, classes for the upcoming week.

Monday Morning Eye Opener, April 25, 2016

Weekly Newsletter from the Northwest District Office for libraries containing programs, activities, classes for the upcoming week.

Monday Morning Eye Opener, May 2, 2016

Weekly Newsletter from the Northwest District Office for libraries containing programs, activities, classes for the upcoming week.

Monday Morning Eye Opener, May 9, 2016

Weekly Newsletter from the Northwest District Office for libraries containing programs, activities, classes for the upcoming week.

Monday Morning Eye Opener, May 16, 2016

Weekly Newsletter from the Northwest District Office for libraries containing programs, activities, classes for the upcoming week.

Monday Morning Eye Opener, May 23, 2016

Weekly Newsletter from the Northwest District Office for libraries containing programs, activities, classes for the upcoming week.

Metabolic activation pattern of distinct hippocampal subregions during spatial learning and memory retrieval.

Activation dynamics of hippocampal subregions during spatial learning and their interplay with neocortical regions is an important dimension in the understanding of hippocampal function. Using the (14C)-2-deoxyglucose autoradiographic method, we have characterized the metabolic changes occurring in hippocampal subregions in mice while learning an eight-arm radial maze task. Autoradiogram densitometry revealed a heterogeneous and evolving pattern of enhanced metabolic activity throughout the hippocampus during the training period and on recall. In the early stages of training, activity was enhanced in the CA1 area from the intermediate portion to the posterior end as well as in the CA3 area within the intermediate portion of the hippocampus. At later stages, CA1 and CA3 activations spread over the entire longitudinal axis, while dentate gyrus (DG) activation occurred from the anterior to the intermediate zone. Activation of the retrosplenial cortex but not the amygdala was also observed during the learning process. On recall, only DG activation was observed in the same anterior part of the hippocampus. These results suggest the existence of a functional segmentation of the hippocampus, each subregion being dynamically but also differentially recruited along the acquisition, consolidation, and retrieval process in parallel with some neocortical sites.