Toxicity, Biocompatibility, pH-Responsiveness and Methotrexate Release from PVA/Hyaluronic Acid Cryogels for Psoriasis Therapy.

Poly(vinyl alcohol)/hyaluronic acid cryogels loaded with methotrexate were studied. The physical⁻chemical characterization of cryogels was performed by FT-IR spectroscopy, scanning electron microscopy, differential scanning calorimetry and dynamic mechanical thermal analysis. Acute toxicity and haematological parameters were determined by "in vivo" tests. The biocompatibility tests proved that the obtained cryogels showed significantly decreased toxicity and are biocompatible. The pH-responsiveness of the swelling behaviour and of the methotrexate release from the poly(vinyl alcohol)/hyaluronic acid (PVA/HA) cryogels were studied in a pH interval of 2⁻7.4. A significant change in properties was found at pH 5.5 specific for treatment of affected skin in psoriasis disease.

Development, optimization and biological evaluation of chitosan scaffold formulations of new xanthine derivatives for treatment of type-2 diabetes mellitus.

New xanthine derivatives as antidiabetic agents were synthesized and new chitosan formulations have been developed in order to improve their biological and pharmacokinetic profile. Their physicochemical properties in terms of particle size, morphology, swelling degree, crystalline state, the loading efficiency as well as in vitro release and biodegradation rate were evaluated. According to the results the optimized formulations have a high drug loading efficiency (more than 70%), small particle size, a good release profile in the simulated biological fluids (the percentage of cumulative release being more than 55%) and improved biodegradation rate in reference with chitosan microparticles. The presence of xanthine derivatives (6, 7) in chitosan microparticles was demonstrated by means of FTIR analysis. The X-ray diffraction (XRD) proved that xanthine derivatives present a crystalline state. The biological evaluation assays confirmed the antioxidant and antidiabetic effects of the xanthine derivatives (6, 7) and their chitosan formulations (CS-6, CS-7). Xanthine derivative 6 showed a high antiradical scavenging effect (DPPH remaining=41.78%). It also reduced the glucose blood level with 59.30% and recorded level of glycosylated hemoglobin was 4.53%. The effect of its chitosan formulation (CS-6) on the level of blood glucose (114.5mg/dl) was even more intense than the one recorded by pioglitazone (148.5mg/dl) when used as standard antidiabetic drug. These results demonstrated the potential application of xanthine derivative 6 and its chitosan formulation (CS-6) in the treatment of the diabetes mellitus syndrome.

Synergic effects of pregabalin-acetaminophen combination in somatic and visceral nociceptive reactivity.

BACKGROUND/AIMS: The present study investigates the effects of pregabalin (PGB), acetaminophen (ACET) and tenoxicam (TNX) administration in somatic and visceral nociception, using the tail flick test and the writhing test in mice. METHODS: In the tail flick test, the substances were administered orally and the latency time response was recorded 15, 30, 60, 90 and 120 min after administration. In the writhing test, pain responses were scored every 5 min during a 30-min period after intraperitoneal injection of diluted acetic acid. RESULTS: Our study demonstrated that oral administration of the combination PGB-ACET resulted in a stronger increase of latency reaction - statistically significant after 15 min compared to TNX and after 30 min compared to PGB in tail flick test. In the writhing test, the combination PGB-ACET, but also PGB-TNX, resulted in a stronger decrease of writhe numbers - statistically significant compared to the effects of the separate administration of each substance. This decrease was more intense in animals treated with the combination PGB-ACET than with PGB-TNX. CONCLUSION: These results suggest an antinociceptive activity which may be a consequence of the synergic action of the substances.