Analysis of two mixtures containing racetams in their pharmaceuticals using simple spectrophotometric methodologies.

BACKGROUND: Green spectrophotometric methods were developed and validated for determination of some CNS active drugs as antiepileptics and brain stimulants. OBJECTIVE: Piracetam (PIR), Levetiracetam (LEV) and Brivaracetam (BRV) were assayed as a ternary mixture using double divisor-ratio spectra derivative (DDRSD) (method I). One more binary co-formulated mixture of Piracetam (PIR) and Vincamine (VIN) was assayed using difference spectrophotometric procedures (method II). METHOD: I was applied to determine PIR at 302nm in the first derivative of the ratio spectra in the selected spectral region. The content of LEV was determined by measuring the spectra at 215nm in the first derivative of the ratio spectra in the selected spectral region. The concentration of BRV was estimated by measuring the first derivative of the ratio spectra in the chosen spectral region and detecting the signals at 229.7nm. The application of method (II) procedures resulted in measuring the absorbance of PIR at 220nm which is the zero crossing point on the difference spectra of VIN in 0.1M NaOH vs. 0.1M HCl. Similarly, the absorbance of VIN was measured at 245.0nm, which is the zero crossing point on the difference spectra of PIR. RESULTS: The suggested methods were fully validated adopting ICH guidelines. The linearity ranged from 10-100µg/mL for the three racetams and from 2-20 for VIN. The recovery percentages were ranged from 98.72% to 101.8% for method I and from 98.13% to 101.06% for method II. Moreover, the proposed methods were proved environmentally benign using the most recent assessment tool named AGREE. CONCLUSION: Both procedures were successfully applied for the determination of each drug in bulk powder, checked using laboratory prepared mixtures, and directly applied on commercially available pharmaceutical products without interference. The obtained results revealed a good agreement with those obtained by the reported methods.

Simultaneous Determination of Formoterol Fumarate and Budesonide Epimers in Metered Dose Inhaler Using Ion-Pair Chromatography.

A simple, accurate and valid ion-pairing chromatographic method was developed for the simultaneous determination of formoterol fumarate (FF) and budesonide (BUD) epimers in metered dose inhaler. The separation was performed on C-18 column using mobile phase consisting of acetonitrile:0.05 M sodium acetate buffer (40:60% v/v) containing 0.03% sodium dodecyl sulfate adjusted to pH 3.1 using increasing volumes of either TEA or orthophosphoric acid isocratically eluted at 1.0 mL/min. Quantitation was achieved with UV detection at 214 nm. The retention times were 3.22, 6.41 and 6.91 min for formoterol fumarate, budesonide epimers B and A, respectively. The linearity range was 0.05-5.0 µg/mL for formoterol fumarate and 0.5-50.0 µg/mL for budesonide. The method was validated for, linearity; lower limit of quantification, lower limit of detection accuracy and precision. The proposed method is rapid (7 min), reproducible (RSD < 2.0%) and achieves satisfactory resolution between FF and BUD B (resolution factor = 12.07). The mean recoveries of the analytes in metered dose inhaler (99.97 and 99.83% for FF and BUD, respectively) were satisfactory.

Spectrophotometric and spectrofluorimetric determination of indacaterol maleate in pure form and pharmaceutical preparations: application to content uniformity.

Two simple, rapid, sensitive and precise spectrophotometric and spectrofluorimetric methods were developed for the determination of indacaterol maleate in bulk powder and capsules. Both methods were based on the direct measurement of the drug in methanol. In the spectrophotometric method (Method I) the absorbance was measured at 259 nm. The absorbance-concentration plot was rectilinear over the range 1.0-10.0 µg mL(-1) with a lower detection limit (LOD) of 0.078 µg mL(-1) and lower quantification limit (LOQ) of 0.238 µg mL(-1). Meanwhile in the spectrofluorimetric method (Method II) the native fluorescence was measured at 358 nm after excitation at 258 nm. The fluorescence-concentration plot was rectilinear over the range of 1.0-40.0 ng mL(-1) with an LOD of 0.075 ng mL(-1) and an LOQ of 0.226 ng mL(-1). The proposed methods were successfully applied to the determination of indacaterol maleate in capsules with average percent recoveries ± RSD% of 99.94 ± 0.96 for Method I and 99.97 ± 0.81 for Method II. In addition, the proposed methods were extended to a content uniformity test according to the United States Pharmacopoeia (USP) guidelines and were accurate, precise for the capsules studied with acceptance value 3.98 for Method I and 2.616 for Method II.

Simultaneous determination of labetalol and furosemide by first-derivative synchronous spectrofluorimetry.

A rapid, simple and highly sensitive first derivative synchronous spectrofluorimetric method was developed for the simultaneous analysis of a binary mixture of labetalol HCl (LBT) and furosemide (FUR) without prior separation. The method was based upon measuring the first derivative of synchronous fluorescence spectra of the two drugs at Deltalambda = 130 nm in aqueous ethanol (55% V/V). The different experimental parameters affecting the synchronous fluorescence of the studied drugs were carefully studied and optimized. The first derivative amplitude-concentration plots were rectilinear over the range of 0.10 to 1.00 microg/mL and 0.05-0.50 microg/mL with lower detection limits of 0.0149 and 7 x 10(-3) microg/mL and quantification limits of 0.045 and 0.021 microg/mL for LBT and FUR, respectively. The proposed method was successfully applied for the determination of the studied drugs in synthetic mixtures. The results obtained were in good agreement with those obtained by the reference methods.

Spectrophotometric determination of labetalol and lercanidipine in pure form and in pharmaceutical preparations using ferric-1,10-phenanthroline.

A simple and sensitive spectrophotometric method was developed for the determination of labetalol HCl (LBT) and lercanidipine HCl (LER) in pure form and in dosage forms. The method was based upon oxidation of the LBT and LER with Fe(+3) and the estimation of the produced Fe(+2) with 1,10-phenanthroline. The absorbance of the tris(1,10-phenanthroline) Fe(+2) complex was measured at 510 nm. Reaction conditions were optimized to obtain colored complex of higher sensitivity and longer stability. The absorbance concentration plots were rectilinear over the concentration rang of 5-90 and 1-20 µg/mL with lower detection limits of 0.74 and 0.01 µg/mL and quantification limits of 2.26 and 0.02 µg/mL for LBT and LER, respectively. The developed method was successfully applied for the determination of LBT and LER in bulk drugs and dosage forms. The common excipients and additives did not interfere in their determinations. There was no significant difference between the results obtained by the proposed and the reference methods regarding Student t-test and the variance ratio F-test.