Further, by changing the blend ratio of high and low molecular PLA, the duration of drug release can be controlled . The molecular weight is directly related to the rate of biodegradation, and thus the greater the molecular weight the slower the speed of degradation, and rate of drug release is also modulated. From the experimental results, it can be suggested that blended polymer matrices could offer promising
avenues for sustained intraocular drug delivery over few months to a year. Additionally, the choice of polymer matrices must be determined carefully Inhibitors,research,lifescience,medical based on the physiochemical properties of the drug to be loaded and the expected duration of release. 3.6. Perspectives on Future Glaucoma Implantable Drug Delivery selleck chemicals systems The classification of glaucoma as a neurodegenerative disease has presented the urgent need to develop strategies for drug delivery to the posterior segment. In a recent glaucoma clinical trial Inhibitors,research,lifescience,medical design and endpoints symposium, FDA emphasized the importance of structural parameters that involve optic disc and retinal nerve fiber layer (RNFL) changes in assessing clinical outcome of new glaucoma therapies . Since preserving vision is the primary goal in glaucoma treatment, Inhibitors,research,lifescience,medical current knowledge of the pathologic factors resulting in optic nerve
damage with or without associated elevated IOP is limited. Considering that elevated IOP is a major risk factor in glaucoma, therapeutic interventions on lowering IOPs alone could help in managing the progression of the disease but may not address the underlying vulnerability of RGCs to degeneration . The key issue is that the current functional measures (i.e., visual acuity, visual field, and contrast sensitivity) used Inhibitors,research,lifescience,medical for evaluation of new drugs and devices do not provide a meaningful relationship between visual field loss and structural change in optic nerve . Even though there are many clinically available implantable delivery systems for ocular diseases and disorders, there is none approved (at the time
of writing) for glaucoma. To set a stage for new treatments in the future, FDA expressed Inhibitors,research,lifescience,medical openness to use structural metrics to measure progression of the disease if they (1) demonstrate strong correlation to clinically relevant functional changes, (2) Idoxuridine provide reproducible measures of clinically significant changes, and (3) are beneficial to the patients . With improvements in imaging technologies, it is expected that combining structural and functional measures can surmount some of the issues in glaucoma clinical trial design and move therapies forward for FDA approval. As such, we consider that effective delivery strategies should implement combination therapeutics that will address the currently identified pathological factors involved in glaucoma. Such an approach will incorporate therapeutic agents that target lowering IOP as well as neuroprotective agents directed at preserving RGC degeneration and apoptosis.