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

Green spectrophotometric methods were developed and validated for determination of some CNS active drugs as antiepileptics and brain stimulants.

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).

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.

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.

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.