پديد آورندگان :
Dinarvand Rassoul نويسنده , Kouchakzadeh Zahra نويسنده , H. Moghadam Shadi نويسنده , Atyabi Fatemeh نويسنده
چكيده لاتين :
Nifedipine (NIF), a 1,4-dihydropyridine calciwn channel antagonist, undergoes photodegradation
to dehydro-nifedipine (DNIF) upon exposure to ultraviolet (UV) light and to the
nitroso analogue of dehydro-nifedipine (NDNIF) when exposed to sunlight or some kinds of
artificial lights. NIF photo-degradation products do not contribute to clinical activity, thus
prevention of photo-degradation of NIF formulations is very important. Large differences
in photo-stability between bioequivalent NIF products could potentially result in the
therapeutic failure of unstable preparations . The aim of this study was to evaluate the effect
of microencapsulation on nifedipine photo-stability. Four different microspheres of nifedipine
were prepared using ethyl cellulose, ethyl cellulose plus titaniwn oxide, pectin and gelatin.
Microspheres were exposed to fluorescent light and the content ofNIF, DNIF and NDNIF for
each product was measured using a specific and sensitive reversed phase high-pressure liquid
chromatography (HPLC) method to determine the extent of photo-decompo sition . In addition,
photo-degradation of pure NIF powder was compared with acidic and buffer solution of NIF.
Solution of NIF degraded in one day, while microencapsulation of NIF prevented the photodegradation
for up to six days against light exposure. Therefore, it may be concluded that
present microencapsulation method without using other compounds such as opaque materials
do not provide enough protection.
