A Multivariate Control Chart Approach for Calibration Transfer between NIR Spectrometers for Simultaneous Determination of Rifampicin and Isoniazid in Pharmaceutical Formulation

Standardization of near infrared spectroscopies via sample spectral correlation equalization

A novel method for near-infrared (NIR) spectroscopy spectra standardization is presented. NIR spectroscopies have been widely used in analytical chemistry, and many methods have been developed for NIR spectra standardization. To establish a robust standardization transformation, most existing methods require spectral data sets from both primal and secondary instruments for 1-1 correspondence validation. However, this limits the usage of standardization methods. This paper investigates an interesting issue, "Can spectra data in sets be arbitrarily order?" and further develops a completely different approach from existing methods in view of statistical signal processing. The key idea is to first compensate for the distortion along the wavelength and intensity of the spectra, and then transfer the second order statistic (2OS) from the primal spectra to the secondary spectra via data sphering and an inverse sphering transform so that the 2OS can be estimated regardless of the sample statistic order. To further demonstrate how the developed method can extend the usage of the NIR spectra standardization, several application-driven experiments on classification and regression are conducted for demonstration, and a comparison to the piecewise direct standardization (PDS) is also studied.

Analytical Methods Practiced to Quantitation of Rifampicin: A Captious Survey

Background:

Rifampicin (RIF), also known as rifampin, a bactericidal antibiotic having broad antibacterial activity against various gram-positive and gram-negative bacteria acts by inhibiting DNA dependent RNA polymerase. RIF has been administered in different dosage forms like tablets, capsules, injections, oral suspension, powder, etc. for the treatment of several types of bacterial infections, including tuberculosis, Mycobacterium avium complex, leprosy and Legionnaires’ disease.

Introduction:

To ensure the quality, efficacy, safety and effectiveness of RIF drug product, effective and reliable analytical methods are of utmost importance. To quantify RIF for quality control or pharmacokinetic purposes, alternative analytical methods have been developed along with the official compendial methods.

Methods:

In this review paper, an extensive literature survey was conducted to gather information on various analytical instrumental methods used so far for RIF.

Results:

These methods were high-performance liquid chromatography (42%), hyphenated techniques (18%), spectroscopy (15%), high-performance thin-layer chromatography or thin-layer chromatography (7%) and miscellaneous (18%).

Conclusion:

All these methods were selective and specific for the RIF analysis.

Standardization of complex biologically derived spectrochemical datasets

Spectroscopic techniques such as Fourier-transform infrared (FTIR) spectroscopy are used to study interactions of light with biological materials. This interaction forms the basis of many analytical assays used in disease screening/diagnosis, microbiological studies, and forensic/environmental investigations. Advantages of spectrochemical analysis are its low cost, minimal sample preparation, non-destructive nature and substantially accurate results. However, an urgent need exists for repetition and validation of these methods in large-scale studies and across different research groups, which would bring the method closer to clinical and/or industrial implementation. For this to succeed, it is important to understand and reduce the effect of random spectral alterations caused by inter-individual, inter-instrument and/or inter-laboratory variations, such as variations in air humidity and CO₂ levels, and aging of instrument parts. Thus, it is evident that spectral standardization is critical to the widespread adoption of these spectrochemical technologies. By using calibration transfer procedures, in which the spectral response of a secondary instrument is standardized to resemble the spectral response of a primary instrument, different sources of variation can be normalized into a single model using computational-based methods, such as direct standardization (DS) and piecewise direct standardization (PDS); therefore, measurements performed under different conditions can generate the same result, eliminating the need for a full recalibration. Here, we have constructed a protocol for model standardization using different transfer technologies described for FTIR spectrochemical applications. This is a critical step toward the construction of a practical spectrochemical analysis model for daily routine analysis, where uncertain and random variations are present.