Copper interactions with DNA of chromatin and its role in neurodegenerative disorders / 药物分析学报

In this study, we have demonstrated the conformational changes to DNA induced by abnormal interactions of copper using circular dichroism, in combination with UV-absorbance and fluorescence spectroscopy. Results confirm that binding of copper to bases of DNA in chromatin is concentration dependent. Binding efficiency of Cu2+ions to DNA is increased in proportion to the degree of unwinding of the double helix induced by denaturation. Altered B-DNA conformation will alter the integrity of DNA which may affect the normal process of DNA replication and transcription. Copper induced DNA damage in the brain may cause neurotoxicity and the neuronal cell death and is implicated in Alzheimer's disease and other neurological disorders.

Formulation development and Theological studies of palatable cefetamet pivoxil hydrochloride dry powder suspension

Because of its intense bitter taste and susceptibility to moisture Cefetamet Pivoxil [CPH] is presently available only in the form of tablet. The aim of this study was to develop taste masked CPH dry powder suspension. Methods employed for formulations were: a] Film coating of CPH using Eudragit El00 and subsequent adsorption on different carriers such as spray-dried lactose, sodium starch glycolate and spray-dried mannitol and b] Complexation of CPH with three different ion exchange resins indion 234 amberlite IRP64 and amberlite IRP69. Taste viz evaluation as recognized by volunteers revealed that coating with Eudragit El00 and subsequent adsorption on different carriers do not mask the bitter taste of the drug. Suspensions prepared using amberlite IRP64 and amberlite IRP69 were extremely palatable with no bitter after taste. They showed pseudoplastic flow behavior and were too viscous even after shearing for sufficient duration of time and exhibited poor pourability. The suspension made with indion 234 was palatable with slight or no bitter after taste. It demonstrated plastic flow with negligible thixotropy. It had moderate viscosity at rest and could be poured after a reasonable amount of shaking. CPH dry powder suspensions were very unstable under different conditions except under refrigeration. A 5% degradation of drug was occurred in reconstituted suspension in 4 days period when stored at room temperature. Dry powder suspension prepared with indion 234 having 5% overages was stable even after 4th day of reconstitution and palatable with slight or no bitter after taste