PREPARATION ORALE RENFERMANT UN ACIDE ORGANIQUE SPECIFIQUE ET PROCEDE D'AMELIORATION DE LA PROPRIETE D'ELUTION ET DE LA STABILITE CHIMIQUE DE LA PREPARATION ORALE
A chemically stable oral preparation with an excellent dissolution propertycomprising as an effective ingredient a specific morphinan derivative or apharmaceutically acceptable acid addition salt thereof is disclosed. The oralpreparation according to the present invention comprises a specific morphinanderivative or a pharmaceutically acceptable acid addition salt thereof as aneffectiveingredient and an organic acid, wherein 1 g of said organic acid requires notless than30 mL of water to dissolve in at 20°C. The method for improvingdissolutionproperty and chemical stability of an oral preparation according to thepresentinvention comprises incorporating an organic acid in the oral preparationcomprisingas an effective ingredient a specific morphinan derivative or apharmaceuticallyacceptable acid addition salt thereof, wherein 1 g of said organic acidrequires notless than 30 mL of water to dissolve in at 20°C.
