Study on the pulmonary delivery system of apigenin loaded albumin nanocarriers with antioxidant activity

Background: Respiratory diseases are mainly derived from acute and chronic inflammation of the alveoli and bronchi. The pathophysiological mechanisms of pulmonary inflammation mainly arise from oxidative damage that could ultimately lead to acute lung injury (ALI). Apigenin (Api) is a natural polyphenol with prominent antioxidant and anti-inflammatory properties in the lung. Inhalable formulations consist of nanoparticles (NPs) have several advantages over other administration routes therefore this study investigated the application of apigenin loaded bovine serum albumin nanoparticles (BSA-Api-NPs) for pulmonary delivery. Methods: Dry powder formulations of BSA-Api-NPs were prepared by spray drying and characterized by laser diffraction particle sizing, scanning electron microscopy, differential scanning calorimetry and powder X-ray diffraction. The influence of dispersibility enhancers(lactose monohydrate and L-leucine) on the in vitro aerosol deposition using a next generation impactor (NGI) was investigated in comparison to excipient-free formulation. The dissolution of Api was determined in simulated lung fluid by using Franz cell apparatus. The antioxidant activity was determined by 2,2-Diphenyl-1-picrylhydrazyl (DPPH˙) free radical scavenging assay. Results: The encapsulation efficiency and the drug loading was measured to be 82.61 ± 4.56% and 7.51 ± 0.415%. The optimized spray drying conditions were suitable to produce particles with low residual moisture content. The spray dried BSA-Api-NPs possessed good the aerodynamic properties due to small and wrinkled particles with low mass median aerodynamic diameter, high emitted dose and fine particle fraction. The aerodynamic properties was enhanced by leucine and decreased by lactose, however, the dissolution was reversely affected. The DPPH˙ assay confirmed that the antioxidant activity of encapsulated Api was preserved. Conclusion: This study provides evidence to support that albumin nanoparticles 49 are suitable carriers of Api and the use of traditional or novel excipients should be taken into consideration. The developed BSA-Api-NPs is a novel delivery system against lung injury with potential antioxidant activity

The atypical anxiolytic drug, tofisopam, selectively blocks phosphodiesterase isoenzymes and is active in the mouse model of negative symptoms of psychosis

Tofisopam is a member of the 2,3-benzodiazepine compound family which is marketed for the treatment of anxiety in some European countries. In contrast to classical 1,4-benzodiazepines, the compound does not bind to the benzodiazepine binding site of the γ-aminobutyric acid receptor and its psychopharmacological profile differs from such compounds. In addition to anxiolytic properties, antipsychotic effects are reported. We now show that tofisopam, 50 mg/kg intraperitoneally (i.p.), administered in parallel to repeated doses of dizocilpine 0.2 mg/kg i.p. can ameliorate dizocilpine-induced prolongation of immobility, which is considered to be a model of negative symptoms of psychosis. We further show that tofisopam acts as an isoenzyme-selective inhibitor of phosphodiesterases (PDEs) with highest affinity to PDE-4A1 (0.42 μM) followed by PDE-10A1 (0.92 μM), PDE-3 (1.98 μM) and PDE-2A3 (2.11 μM). The data indicate that tofisopam is an interesting candidate for the adjuvant treatment of psychosis with focus on negative symptoms. Combined partial inhibition of PDE-4 and PDE-10 as well as PDE-2 may be the underlying mechanism to this activity. Due to the good safety profile of tofisopam as evident from long-term use of this agent in patients, it may be concluded that dual or triple inhibition of PDE isoenzymes with additive or synergistic effects may be an interesting approach to pharmacological activity, resulting in active compounds with beneficial safety profile. Dose-limiting side effects such as emesis induced by selective inhibition of PDE-4 may be prevented by such strategies

Optimization of Freeze Drying Process Using Isomalt as Bulking Agent

Freeze dried products form a special group of sterile medications because of the unique manufacturing process. [...