Ultraviolet spectrophotometric
method for the determination of celecoxib in
bulk and its pharmaceutical formulation (dispersible tablets
and capsules) has been developed. The absorbance maxima of
celecoxib in a mixture of methanol and 0.01 N sodium hydroxide
(1:1 v/v) were determined at 253.1 nm. Beer’s law is obeyed
over concentration range of 8–22 lg mL1 with correlation
coefficient r > 0.999 (Sahu et al., 2009).
Two simple and sensitive spectrophotometric methods have
been developed for the quantitative estimation of celecoxib
from its capsule formulation. The first method is a UV spectrophotometric
method using methanol as solvent; the drug
showed absorption maximum at 253.2 nm in methanol and linearity
was observed in the concentration range of 5.0–
15 lg mL1
. The second method is a visible spectrophotometric
method, based on formation of red coloured complex of
drugs with o-phenanthroline and ferric chloride, the complex
showed absorbance maximum at 509.2 nm and linearity was
observed in the concentration range of 50–400 lg mL1 (Pillai
and Singhvi, 2006).
A simple fluorescence method was developed for the direct
determination of celecoxib in capsules. The capsules were emptied,
pulverized and dissolved in either ethanol or acetonitrile,
sonicated and filtered. Direct fluorescence emission was measured
at 355 ± 5 nm (exciting at 272 nm). The method was
fully validated and the recoveries were excellent, even in presence
of excipients (Damiani et al., 2003).
2.2.