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Rotival R.,University of Paris Descartes | Rotival R.,Laboratoire Of Controle Qualite | Corvis Y.,University of Paris Descartes | Cartigny Y.,CNRS Separative Sciences and Methods | And 7 more authors.
CrystEngComm | Year: 2013

The use of an integrative analytical approach allowed us to establish the intrinsic solid state stability of bethanechol chloride (BC), an active pharmaceutical ingredient used in the treatment of urinary retention. First, the crystal structure of the monoclinic form has been described using single crystal X-ray diffraction studies. Second, thermal analyses revealed that the compound degrades upon melting, with an apparent melting temperature estimated to be 231 °C. No transition from the monoclinic to the orthorhombic form has been observed, suggesting that the monoclinic form is the stable one. Third, the two-step melting-decomposition process has been elucidated by liquid chromatography and thermogravimetry coupled to mass spectrometry. The first step corresponds to the sample liquefaction, which consists of the gradual dissolution of bethanechol chloride in its liquid degradant, i.e. betamethylcholine chloride. This step is in agreement with Bawn kinetics and the activation energy of the reaction has been estimated at 35.5 kcal mol -1. The second step occurs with accelerated degradation in the melt. Elucidation of secondary decomposition pathways evidenced autocatalytic properties conferred by the formation of both isocyanic acid and methyl chloride. Finally, dynamic water vapor sorption analysis showed a substantial hygroscopicity of the drug substance. A deliquescent point has been determined at 56% relative humidity at 25 °C. © 2013 The Royal Society of Chemistry. Source


Hassane S.O.S.,Universite Ibn Tofail | Hassane S.O.S.,University des Comores | Hassane S.O.S.,Laboratoire Of Controle Qualite | Satrani B.,Universite Ibn Tofail | And 4 more authors.
Phytotherapie | Year: 2011

This work aims to study of antibacterial and antifungical activities and chemical composition of essential oils of Ocimum canum Sims, harvested in the regions of Maweni-Dimani and Ivoini-Mitsamihouli on the island of Grande Comore. The yields of essential oil showed that Ocimum canum from Maweni-Dimani (2.06%) is higher than for Ivoini-Mitsamihouli (1.4%). The first one essential oil presents 1,8-cineole (48.88%), camphor (14.98%), α-pinene (5.71%), β-pinene (4.66%) and γ-elemene (3.91%) as predominate constituents. The second sample is mainly composed by 1,8-cineole (34.22%), camphor (13.69%), isopropyl propanoate (9.13%), γ-elemene (5.43%) and α-pinene (3.83%). The antimicrobial activity of two essential oils of two sources has been studied against eleven microorganisms. The essential oil of Ivoini-Mitsamihouli inhibits bacteria, fungus and mildews particularly at low concentrations compared to that of Maweni-Dimani. © 2011 Springer Verlag. Source

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