Applications and prospects of intra-articular drug delivery system in arthritis therapeutics.

Arthritis is a kind of chronic disease that affects joints and muscles with the symptoms of joint pain, inflammation and limited movement of joints. Among various clinical therapies, drug therapy has been extensively applied because of its accessibility, safety and effectiveness. In recent years, the intra-articular injection has dramatic therapeutic effects in treating arthritis with high patient compliance and low side effects. In this review, we will introduce pathology of arthritis, along with the accessible treatment and diagnosis methods, then we will summarize major advances of current hopeful intra-articular delivery systems such as microspheres, hydrogels, nanoparticles and liposomes. At last, some safety assessments in the preclinical work and the main challenges for the further development of intra-articular treatment were also discussed.

Glucose-Responsive Microspheres as a Smart Drug Delivery System for Controlled Release of Insulin.

BACKGROUND AND OBJECTIVES: Diabetes mellitus, a disease of glucose regulation, has become one of the most common medical problems in the world. At present, alternative therapy for diabetes has, to a large extent, been widely concerned with the improvement of treatment efficacy. The aims of this study were to characterize and evaluate the surface morphology of the novel glucose-responsive injectable microspheres containing insulin, along with their in vitro release and in vivo efficacy. METHODS: In this study, glucose-responsive microspheres as an emerging smart drug delivery system for controlled release of insulin were developed by an improved water-in-oil-in-water (W/O/W) double emulsion preparation method. Here, methoxypolyethylene glycol-hydrazone-4-methoxypolyethylene glycol benzoate (mPEG-Hz-mPEG4AB) was synthesized as a pH-responsive carrier. RESULTS: The microspheres had a good spherical structure with a particle size of 5 ~ 10 µm. Approximately 61% of insulin was released in 15 h under a high glucose environment but was barely released within the normal glucose range in in vitro studies. After a subcutaneous injection of insulin microspheres in rats, blood glucose levels rapidly decreased within 2 h and could be maintained for 2 days in the normal range. Histopathological evaluation indicated that the microspheres were almost non-irritating. CONCLUSIONS: The pH-responsive mPEG-Hz-mPEG4AB could be used as an efficient insulin microsphere carrier, and the optimized microspheres had good morphology and sustained hypoglycemic effect.

Preparation and evaluation of novel multi-channel orally disintegrating tablets.

In this study, novel orally disintegrating tablets (ODTs) with multi-channel structure were designed to provide a rapid disintegration and subsequently drug dissolution. The ODTs were prepared using conventional wet compression through perforating channels with a special multi-channel mold. A modified sieve method was used in disintegration test as a quick screening tool during formulation evaluation. Moreover, physical properties, in vitro and in vivo disintegration time, dissolution rate and mouthfeel were also evaluated. The results demonstrated that developed multi-channel ODTs had good physical parameters, in vitro/in vivo correlation (IVIVC) of disintegration time and acceptable mouthfeel and dissolution. It also revealed that the presence of channels could accelerate the disintegration of ODTs because the channels could shorten the distance of water penetration and increased the specific surface area, resulting in a significant reduction in disintegration time. Above all, the introduction of novel multi-channel ODTs provided an alternative preparation method for ODTs and achieved good disintegration characteristics.