Spectrophotometric methods for the determination of letrozole in bulk and pharmaceutical dosage forms

Abstract

Ultraviolet (UV), first derivative, second derivative, and AUC-spectrophotometric methods for the determination of letrozole in pharmaceutical formulations have been developed. For UV-spectrophotometry, the standard solutions were measured at 240.0 nm. The linearity ranges were found to be 0.25–20.0 μgml–1 in methanol and the regression equation was A=1.20×10–1C+2.22×10–2(r2=0.9994). For the first derivative spectrophotometry, the response (dA/dλ) of standard solutions was measured at 224.0 nm. The calibration curve was constructed by plotting dA/dλ values against concentrations 0.25–20.0 μgml–1, of letrozole. The regression equation of the linear calibration graph was calculated as D1=3.89×10–3C+1.85×10–4(r2=0.9987). For the second derivative spectrophotometry, the response (d2A/dλ2) of standard solutions was measured at 241.0 nm. The calibration curve was constructed by plotting d2A/dλ2 values against concentrations 0.5–20.0 μgml–1 of letrozole standards in methanol. The regression equation of the linear calibration graph was calculated as D2=-1.59×10–3C-4.66×10–4(r2=0.9985). The AUC-spectrophotometric method was based on the calculation of Area under Curve (AUC), for analysis of letrozole in the wavelength range of 235.0–245.0 nm. The calibration curve was constructed by plotting AUC values against concentrations 0.25–20.0 μgml–1, of letrozole. The regression equation of the linear calibration graph was calculated as AUC=1.132C+0.2153 (r2=0.9994). The methods were validated by following the analytical performance parameters suggested by the International Conference on Harmonization (ICH). All validation parameters were within the acceptable range. The developed methods were successfully applied to estimate the amount of letrozole in pharmaceutical formulations.

Development and Validation of Uv-Spectrophotometric Methods for Determination of Gemcitabine Hydrochloride in Bulk and Polymeric Nanoparticles

“…Ruggedness was determined by different analysts, using similar operational and environmental conditionsand the results were reported in terms of % RSD [22].…”

Letrozole Determination by Capillary Zone Electrophoresis and UV Spectrophotometry Methods

“…The detection was carried out in UV at 240 nm, in accordance with our recorded UV absorption spectra of LET and data previously reported in literature [25][26][27][28]. In CZE capillary preconditioning is necessary for removing adsorbed material from the capillary wall [29].…”

“…A concentration of 100 µg·mL -1 of LET was set. The amount of LET from pharmaceutical tablets and standard deviation (SD) were calculated using linear regression equation of the standard curve (Table I) [26]. The recovery (%) from pharmaceutical formulation was 99.63 ± 1.51 (average of three replicates).…”

“…The electrophoretic methods are more advantageous through accessibility than other expensive analytical methods as HPLC and RP-HPLC, LC-MS/MS or SPE-UPLC-MS/MS [20][21][22][23][24]. For determination of LET in bulk and pharmaceutical formulations spectrophotometric method are also frequently used [25][26][27].…”

Omega 3 fatty acid-enriched nanoemulsion of thiocolchicoside for transdermal delivery: formulation, characterization and absorption studies

“…Supernatant was taken and filtered through a 0.45 mm member filter. The concentration of TCC was determined in each oil spectrophotometrically at the wavelength of 259 nm Acharjyask et al (2010). For the selection of surfactant and co-surfactant, miscibility of oil having maximum solubility of TCC was done with a numbers of surfactants.…”