TY - BOOK AU - Yosra Zakaria Sewilam AU - Maha Abdelmonem Hegazy , AU - Nagiba Yehia Hassan , AU - Soheir Abdelfattah Weshahy , TI - Analytical study on some drugs used in treatment of CNS disorders / PY - 2016/// CY - Cairo : PB - Yosra Zakaria Sewilam , KW - Bromazepam KW - Entacapone KW - Levodopa N1 - Thesis (M.Sc.) - Cairo University - Faculty of Pharmacy - Department of Analytical Chemistry; Issued also as CD N2 - Multicomponent pharmaceutical formulations have gained a lot of importance due to greater patient acceptance as a result of reduced pill burden, increased potency and multiple actions. Accordingly, estimation of drugs in combination therapy simultaneously is an important part in the field of pharmacy as it saves time of separation and yields accurate and precise results. As most pharmaceutical compounds are subjected to degradation which results in change in their activity, stability-indicating assay methods were developed for the selective determination of the intact drug in the presence of its degradation product. In this study different analytical techniques were applied for analysis of some CNS acting drugs either in combination or in the presence of their degradates. The chosen drugs are namely entacapone, bromazepam, levodopa and carbidopa. The aim of the work was to develop accurate, economic and selective methods for the analysis of the chosen drugs simultaneously in combination dosage forms and without interference from their degradates and to investigate the stability of the studied drugs according to ICH guidelines by exposing it to different stress conditions followed by developing stability indicating assay methods for the analysis of the active ingredient in presence of its degradation product. The proposed methods were simple, accurate, and reproducible, which would be feasible and sensitive for the determination of the studied drugs and were validated according to ICH-guideline UR - http://172.23.153.220/th.pdf ER -