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Copyright @ Pol J Cosmetol
Pol J Cosmetol 2011, 14(2): 123-131pl,en  Rheological parameters and pharmaceutical availability of morphine hydrochloride from anhydrous absorptive ointmentsGrażyna Samczewska, Magdalena Piechota-Urbańska Zakład Farmacji Aptecznej, Katedra Farmacji Stosowanej, Uniwersytet Medyczny w Łodzi Summary Introduction. Morphine and its salts are stable compounds in solid state in the absence of water. They degrade easily under the effect of water and oxygen dissolved in it. Propane-1,2-diol (propylene glycol) is an alternative solvent for morphine salts in topical formulations. Aim. To design a prescription for anhydrous absorptive ointments with morphine hydrochloride (MH), test their pH, rheological properties and the rate of analgesic release through a semipermeable membrane to water. Material and methods. There were tested vehicles and ointments of different content of white soft paraffin, anhydrous lanolin but constant content of propylene glycol (vehicle) or glycol solution of morphine hydrochloride (ointment). Extensibility of the formulations was determined by extensiometric method; pH by potentiometric method. Viscosity parameters were determined using a digital cone-plate rheometer. Pharmaceutical availability of morphine was tested by spectrophotometric method. Results. Increase of pH, decrease of perspiration number, extensibility and viscosity with the increase of percentage content of lanolin were observed both in the case of vehicles and ointments. Pharmaceutical availability of MH was the highest from ointment of 16% content of lanolin. Key words: anhydrous absorptive ointments, morphine hydrochloride, propylene glycol, rheology, pharmaceutical availability |