Polymeric cyclosporine-A nanoparticles for ocular application

In the present study, cyclosporine A (CsA) was incorporated successfully into cationic Eudragit RS 100 nanoparticles (EPNs) aiming ocular application. Physicochemical characterization of the EPNs prepared was performed during the storage period of 6 months. Following in vitro release tests, sheep were used in in vivo studies where 100 microL of formulation was applied to both eyes (n = 6) under veterinarian supervision. Aqueous and vitreous humour samples were collected at predetermined time intervals and analyzed by enzyme immune assay (EIA). In vitro relase studies showed the extended release of the incorporated drug from the nanoparticles. However in vivo results demonstrated the prolonged residence time of CsA in the deeper layers (vitreous humour) of the eye with positively charged EPNs.

4-difluoro-substituted phenl-5-oxohexahydroquinoline derivatives and their effects on calcium channels

Twenty new methyl(ethyl) 2,6,6- or 2,7,7-trimethyl-5-oxo-4-(disubstituted phenyl)-1,4,5,6,7,8-hexahydroquinoline-3-carboxylates and ten new N,N-diethyl-2,6,6- or 2,7,7-trimethyl-5-oxo-4-(disubstituted phenyl)-1,4,5,6,7,8-hexahydroquinoline-3-carboxamide derivatives have been synthesised and screened for their calcium channel antagonistic activity. The compounds were synthesised by the Hantzsch reaction. Calcium antagonistic activities of the compounds were determined by the tests performed on isolated rat ileum and rat thoracic artery.

New 8-substituted xanthiene derivatives as potent bronchodilators

The synthesis and structure determination of 8-aryl /alkyl aryl 1, 3-dimethyl-3, 7-dihydropurin-2, 6-dione derivatives (1-13), was carried out in this study. Bronchodilator activity is investigated using isolated guinea-pig tracheal strips, pre-contracted by acetylcholine and histamine. Spasmolytic activity of the compounds was compared to theophylline. Synthesized compounds (1-13) did not inhibit the acetylcholine-induced pre-contractions except compound (8) at 10(-5) M concentration. In contrast, some of the compounds, especially (7), (11), (12) at 10(-5) M and (3), (4), (9) and (11) in 10(-4) M displayed inhibitory activity on the tracheal strips pre-contracted by histamine. The potency of the compounds at human adenosine receptors was evaluated using radioligand binding assay and a cyclic AMP functional assay in CHO cells expressing these receptors. Compound (11) displayed the greatest activity against radioligand binding of specific agonists to A2A and A2B receptors. The compounds were relatively selective for both A2A and A2B compared with A1 and A3 receptors. All compounds were also tested for the inhibition of NECA-induced cAMP accumulation mediated by the A2B adenosine receptor and compound (11) was found to be the most effective. Our results showed that these compounds are acting as selective adenosine antagonists, especially for adenosine A2B receptors, and are promising as potent anti-inflammatory agents rather than bronchodilator for the treatment of asthma.

Studies on 3-diethylaminocarbonyl-1,4,5,6,7,8-hexahydroquinoline derivatives and their calcium channel antagonistic activities in vitro

In this study, thirteen 2,6,6-trimethyl-3-carbamoyl-4-aryl-5-oxo-1,4,5,6,7,8-hexahydroquinoline derivatives were synthesized and screened for their calcium channel antagonistic actitivities. The hexahydroquinoline derivatives were synthesized according to Hantzsch reaction. The structures of the compounds were elucidated by IR, 1H-NMR, 13C-NMR, Distortionless Enhancement Polarization Transfer (DEPT), Correlation Spectroscopy (COSY), mass spectroscopy and elemental analyses. The calcium antagonistic activities of the compounds were determined by tests performed on isolated rat ileum and lamb carotid artery. In isolated rat ileum, compounds 8, 12 and 13 were found to be more active than nicardipine (CAS 55985-32-5) at a concentration of 10(-5) mol/L. At the concentration 10(-4) mol/L, compounds 7 and 12 were more active than nicardipine and compounds 5, 8 and 13 were equipotent. In lamb carotid artery studies, at the concentration 10(-5) mol/L all compounds were found to be less active than nicardipine; at the concentration 10(-4) mol/L compounds 5 and 13 showed greater inhibition than nicardipine. At this concentration, compound 9 was found to be as active as nicardipine.

Studies on calcium antagonist activities of 2-ethyl-3-carbmethoxy-4-aryl- 5-oxo-6,6-dimethyl-1,4,5,6,7,8-hexahydroquinoline derivatives

In this study, 23 new compounds having 2-ethyl-3-carbmethoxy-4-aryl-5-oxo-6,6-dimethyl-1,4,5,6,7, 8-hexahydroquinoline structure have been synthesised and screened for their calcium antagonistic activities. The structure of the compounds were characterised by IR, 1H-NMR, 13C-NMR, mass spectroscopy and elemental analyses. The calcium antagonistic activities of the compounds were determined by the tests performed on isolated rat ileum and lamb carotid artery. Although none of the synthesized compounds were as active as nicardipine in isolated rat ileum, the compounds 9, 10 and 19 have shown high activity. In screening studies on lamb carotid artery, compounds 10, 14 and 19 have been found active at a concentration of 10(-4) mol/l.