title: Kinetic Study of the Alkaline Degradation of Oseltamivir Phosphate and Valacyclovir Hydrochloride using Validated Stability Indicating HPLC.
abstract: Aqueous alkaline degradation was performed for oseltamivir phosphate (OP) and valacyclovir hydrochloride (VA). Isocratic stability indicating the use of high-performance liquid chromatography (HPLC) was presented for each drug in the presence of its degradation product. The separations were performed using the Nucleosil ODS column and a mobile phase consisting of phosphate buffer (pH = 7), acetonitrile, and methanol 50:25:25 (v/v/v) for OP. For VA separation, a Nucleosil CN column using phosphate buffer (pH = 7) and methanol 85:15 (v/v) was used as a mobile phase. Ultraviolet detection at 210 nm and 254 nm was used for OP and VA, respectively. The method showed high sensitivity concerning linearity, accuracy, and precision over the range 1-250 μg mL(-1) for both drugs. The proposed method was used to determine the drug in its pharmaceutical formulation and to investigate the degradation kinetics of each drug's alkaline-stressed samples. The reactions were found to follow a first-order reaction. The activation energy could also be estimated. International Conference on Harmonisation guidelines were adopted for method validation.
authors.affiliation: Pharmaceutical Chemistry Department, Faculty of Pharmacy, Cairo University, Egypt.
authors.forename: Ramzia I
authors.initials: RI
authors.lastname: Al-Bagary
authors.affiliation: Pharmaceutical Chemistry Department, Faculty of Pharmacy, Cairo University, Egypt.
authors.forename: Asmaa A
authors.initials: AA
authors.lastname: El-Zaher
authors.affiliation: National Organization for Drug Control and Research (NODCAR), Dokki, Giza, Egypt.
authors.forename: Fahima A
authors.initials: FA
authors.lastname: Morsy
authors.affiliation: National Organization for Drug Control and Research (NODCAR), Dokki, Giza, Egypt.
authors.forename: Mai M
authors.initials: MM
authors.lastname: Fouad
keywords: degradation kinetic; oseltamivir phosphate; stability indicating high-performance liquid chromatography; valacyclovir hydrochloride