Conclusion: A simple, cost-effective, and sensitive spectrofluorimetric method was developed and validated for the determination of TOL in human plasma and pharmaceutical preparations using dansyl chloride. According to this validation study, it is possible to use this proposed method for the routine analysis of the drug and for conducting bioavailability and bioequivalence studies with good accuracy and precision.
Keywords: Tolterodine, dansyl chloride, pharmaceutical preparations, plasma, derivatization
The dansylation reactions were performed in a water bath at 60[degrees]C for 60 min, after which 10 [micro]L of sodium hydroxide solution (250 mM) was added to quench the excess dansyl chloride
. After an additional 10 min incubation (60[degrees]C), 50 [micro]L of 425 mM formic acid in ACN/[H.sub.2]O (1: 1,v/v) was added to neutralize the solution.
For amino acid analysis, KHCO3-KOH solution (pH 9.8), methanol, and dansyl chloride were added to the standards and samples.
The samples were alkalized with KHC[O.sub.3] solution (pH 9.8), mixed with methanol, derivatized with dansyl chloride in the dark, and incubated at 80[degrees]C for 20 minutes, and 10 [micro]l acetic acid was added to stop the reaction.
Dansyl chloride is a time-honored fluorescent compound for the SC.
However, this procedure possibly represents a pitfall when the test product removes dansyl chloride from the SC .
A 200-[micro]L aliquot of each extract was added to 200 [micro]L of saturated [Na.sup.+], CO and 400 [micro]L of dansyl chloride
(5 mg per mL of acetone) at room temperature, and mixed for 90 min at 70 [degrees]C in the dark.
HPLC-grade acetonitrile and methylene chloride were obtained from EM Science, and dansyl chloride, estriol, estrone sulfate, and ethinylestradiol were obtained from Sigma-Aldrich.
Derivatization with dansyl chloride, as described below, was highly effective and was therefore used for all studies described for the LC-MS/MS method (31).
A sensitive fluorescence technique using dansyl chloride
to assess hair damage.
Gal-Hyl can be measured using an amino acid analyzer (12), but simpler methods have been developed for measurement of urinary Gal-Hyl, using HPLC after derivatization with dansyl chloride