Long-Acting Microparticle Formulation of Griseofulvin for Ocular Neovascularization Therapy.

Neovascular age-related macular degeneration (nAMD) is a leading cause of vision loss in older adults. nAMD is treated with biologics targeting vascular endothelial growth factor; however, many patients do not respond to the current therapy. Here, a small molecule drug, griseofulvin (GRF), is used due to its inhibitory effect on ferrochelatase, an enzyme important for choroidal neovascularization (CNV). For local and sustained delivery to the eyes, GRF is encapsulated in microparticles based on poly(lactide-co-glycolide) (PLGA), a biodegradable polymer with a track record in long-acting formulations. The GRF-loaded PLGA microparticles (GRF MPs) are designed for intravitreal application, considering constraints in size, drug loading content, and drug release kinetics. Magnesium hydroxide is co-encapsulated to enable sustained GRF release over >30 days in phosphate-buffered saline with Tween 80. Incubated in cell culture medium over 30 days, the GRF MPs and the released drug show antiangiogenic effects in retinal endothelial cells. A single intravitreal injection of MPs containing 0.18 µg GRF releases the drug over 6 weeks in vivo to inhibit the progression of laser-induced CNV in mice with no abnormality in the fundus and retina. Intravitreally administered GRF MPs prove effective in preventing CNV, providing proof-of-concept toward a novel, cost-effective nAMD therapy.

Engineering microenvironment of biodegradable polyester systems for drug stability and release control.

Polymeric systems made of poly(lactic acid) or poly(lactic-co-glycolic acid) are widely used for long-term delivery of small and large molecules. The advantages of poly(lactic acid)/poly(lactic-co-glycolic acid) systems include biodegradability, safety and a long history of use in US FDA-approved products. However, as drugs delivered by the polymeric systems and their applications become more diverse, the significance of microenvironment change of degrading systems on long-term drug stability and release kinetics has gained renewed attention. In this review, we discuss various issues experienced with acidifying microenvironment of biodegradable polymer systems and approaches to overcome the detrimental effects of polymer degradation on drug stability and release control.

Local drug delivery systems for inflammatory diseases: Status quo, challenges, and opportunities.

Inflammation that is not resolved in due course becomes a chronic disease. The treatment of chronic inflammatory diseases involves a long-term use of anti-inflammatory drugs such as corticosteroids and nonsteroidal anti-inflammatory drugs, often accompanied by dose-dependent side effects. Local drug delivery systems have been widely explored to reduce their off-target side effects and the medication frequency, with several products making to the market or in development over the years. However, numerous challenges remain, and drug delivery technology is underutilized in some applications. This review showcases local drug delivery systems in different inflammatory diseases, including the targets well-known to drug delivery scientists (e.g., joints, eyes, and teeth) and other applications with untapped opportunities (e.g., sinus, bladder, and colon). In each section, we start with a brief description of the disease and commonly used therapy, introduce local drug delivery systems currently on the market or in the development stage, focusing on polymeric systems, and discuss the remaining challenges and opportunities in future product development.

Development and characterization of an organic solvent free, proliposomal formulation of Busulfan using quality by design approach.

Parenteral administration of Busulfan (BU) conquers the bioavailability and biovariability related issues of oral BU by maintaining the plasma drug concentration in therapeutic range with minimal fluctuations thereby significantly reducing the side effects. Busulfex® is the only commercially available parenteral formulation of BU composed of organic solvents N, N-dimethylacetamide and polyethylene glycol 400. Since, BU is highly susceptible to hydrolytic degradation; Busulfex® has poor physical and chemical stability in IV fluids. It is quintessential to develop organic solvent free formulation of BU using parenterally acceptable excipients to enhance its solubility and stability in IV fluids. The Proliposomal formulation of BU was prepared by adsorption-sonicaton method using egg phosphotidylcholine, cholesterol, tween 80 and mannitol. Vesicle size and entrapment efficiency were optimized using 24 full factorial design and characterized by DSC, PXRD and TEM. Optimized formulation spontaneously forms 74.0 ± 1.7 nm sized nanovesicles with 72.9 ± 1.5 % entrapment efficiency. DSC and PXRD studies revealed that BU was present in phospholipid bilayer in amorphized form and TEM images confirmed the multi lamellar vesicular structure. Physicochemical stability of BU was significantly enhanced with proliposomal formulation. In-vivo studies in Sprague Dawley rats showed proliposomal formulation has comparable immunosuppression activity and 110.62 % relative bioavailability as compared to marketed Busulfan formulation i.e. Busulfex®.