Quantitative Acyclovir Determination by FT-Raman Spectroscopy, Dr C.A. Georgiou

  • Raman bands observed at 1690,1630, 1574, 1482, 1181, 578, and 508 cm-1 were used for univariate calibration.
  • Correlation coefficients of the calibration curves were in the range of  0.997-0.9993 and 0.996-0.9991 for band intensity and band area measurements, respectively. 
  • Detection limits were in the range of 2.8-11.1 and 3.7-8.8 % w/w for band intensity and  band area measurements, respectively. Precision ranged between 0.7-5.6 and 0.4-4.5 % RSD (n=3) for band intensity and band area measurements, respectively.
  • Results obtained by the proposed method, are equivalent to those acquired  through the HPLC reference method.
  • Tablets are analyzed through their package (figure 1), without any interference from the package (figure 3)
  • Stepwise multiple linear regression (MLR) was also applied for calibration. The model C = -(3 ± 1) - (13 ± 4) x BI1690 + (3.5 ± 0.5) x BI1482, (r = 0.997) gave the best fit. Relative differences between the FT-Raman and the reference method were in the range of  (-5.4) - (2.0) %.
  • The proposed solid-state FT-Raman method has the advantage of being fast, simple and can be used for the precise and accurate analysis of commercial pharmaceutical solid dosage forms without opening their PVC-blister packages.

Solid pharmaceutical dosage forms are analysed through their PVC-blister package

Raman spectra acquired during calibration

Standards of
(a) 0, (b) 5, (c) 10, (d) 30, (e) 50, (f) 70, (g) 90 and (h) 100 % w/w

FT-Raman spectra acquired from

The PVC-blister (a) and packaged tablets of the Zovirax 200mg (b) and Herzkur 400 mg (c) formulations.
The scale of spectrum (a) is 10 times the scale of spectra (b) and (c).

Questions and comments to author: Dr C.A. Georgiou, cag@aua.gr
Phone: +301-5294248, fax: +301-5294265
Chemistry Laboratory, Agricultural University of Athens, Greece