Study of Pharmaceutical Samples using Optical Emission Spectroscopy and Microscopy

Abstract

The growth of the pharmaceutical industry to keep pace with the well-being of humans worldwide has posed many challenges related to quality control. This paper reports on the potential application of a modern optical spectroscopic technique popularly known as laser-induced breakdown spectroscopy (LIBS) to address some quality aspects such as the sample constituents, hardness, and classification of five different pharmaceutical samples. The surface analysis of these samples has been carried out using optical microscopy (OM) and atomic force microscopy (AFM). The LIBS spectra of different pharmaceutical samples of different brands have been recorded in air at atmospheric pressure using a high-energy Nd:YAG laser and an echelle spectrometer coupled with an intensified charge-coupled device camera. The LIBS spectrum provides the spectral signatures of lighter elements like carbon (C), hydrogen (H), nitrogen (N), oxygen (O), and the CN violet band, along with inorganic elements like calcium (Ca), magnesium (Mg), etc. Two different multivariate analysis methods, principal component analysis (PCA) and artificial neural network (ANN), have been employed with the LIBS spectral data matrix to obtain the classification of these samples. OM and AFM were used to investigate the surface quality of the tablets, which helps the pharmaceutical industry in increasing the life of pharmaceutical products. The LIBS-based hardness of the sample matrices is estimated, and a correlation has been established with AFM-based RMS roughness. The results illustrate the strength of the LIBS coupled with multivariate analysis like PCA and ANN for a rapid and reliable analysis of pharmaceutical products. Also, LIBS coupled with OM and AFM might be an effective way to address surface quality aspects of pharmaceutical samples.

Elemental analysis and metabolic profiling of medicinally potent members of Zingiberaceae family using FT-IR and LIBS coupled with PLS-DA

“…For LIBS analysis, the plant materials of all seven samples (G1 to G7), listed in Table 1 , were thoroughly washed using double-distilled water and left for air drying at room temperature in a shady area. The samples were analyzed at the LIBS facilities of Comenius University, Bratislava, Slovakia, using a simple experimental scheme similar to that used in our previous works [ 34 , 35 ]. Briefly, for our experiment, a high energy Q-switched Nd:YAG laser (Brilliant Eazy, Quantel, wavelength 1064 nm) was used as a source, with a pulse duration of 5 ns, a repetition rate of 2 Hz, and an optimized energy of 10 mJ per pulse.…”

Atomic spectrometry update: review of advances in the analysis of metals, chemicals and materials

“…The effects of several polyatomic ions could be alleviated including some that did not originate from the germanium matrix. These interferences included but were not limited to 35 Cl 16 O + , 40 Ar 16 OH + , 38 Ar 18 OH + , 70 GeH + , 40 Ar 35 Cl + , 73 Ge 16 O + and 74 Ge 16 O + which would normally interfere with 51 V + , 57 Fe + . 57 Fe + , 71 Ga + , 75 As + , 89 Y + and 90 Zr + , respectively.…”

“…Dwivedi et al used optical and atomic force microscopy to analyse the surface of tablets and LIBS to analyse the chemical constituents and to quantify the hardness . 70 Using a Nd:YAG laser and a spectrometer equipped with an intensified CCD the analytes C, Ca, H, Mg, N and O as well as CN were determined. The multivariate methods of PCA and ANN were used in an attempt to classify drugs made by five different manufacturers.…”