Screening of unapproved drugs using portable Raman spectroscopy.

We present a four-step screening approach for unapproved drugs. The screening approach is both qualitative and quantitative in design in order to determine if the sample under study contains the correct and acceptable amount of the declared active pharmaceutical ingredient. Four commercially-available unapproved antibiotic and antiviral drugs were used in this study.

Quantitative determinations using portable Raman spectroscopy.

A portable Raman spectrometer was used to develop chemometric models to determine percent (%) drug release and potency for 500mg ciprofloxacin HCl tablets. Parallel dissolution and chromatographic experiments were conducted alongside Raman experiments to assess and compare the performance and capabilities of portable Raman instruments in determining critical drug attributes. All batches tested passed the 30min dissolution specification and the Raman model for drug release was able to essentially reproduce the dissolution profiles obtained by ultraviolet spectroscopy at 276nm for all five batches of the 500mg ciprofloxacin tablets.

Raman Barcode for Counterfeit Drug Product Detection.

Potential infiltration of counterfeit drug products-containing the wrong or no active pharmaceutical ingredient (API)-into the bona fide drug supply poses a significant threat to consumers worldwide. Raman spectroscopy offers a rapid, nondestructive avenue to screen a high throughput of samples. Traditional qualitative Raman identification is typically done with spectral correlation methods that compare the spectrum of a reference sample to an unknown.

A highly sensitive nanoscale pH-sensor using Au nanoparticles linked by a multifunctional Raman-active reporter molecule.

Chemical sensing on the nanoscale has been breaking new ground since the discovery of surface enhanced Raman scattering (SERS). For nanoparticles, controlled particle aggregation is necessary to achieve the largest SERS enhancements. Therefore, aggregating agents such as salts or linker molecules are used in conjunction with chemically sensitive reporters in order to develop robust environmentally sensitive SERS probes.

Precise monitoring of chemical changes through localization analysis of dynamic spectra (LADS).

We present a method for monitoring subtle (sub-wavenumber) dynamics within time-varying spectra. Peak fitting is performed for large numbers of spectra in a series, allowing for monitoring time evolutions of peak positions with high precision and confidence. Sub-wavenumber peak shifts due to physical or chemical changes in the sample can be monitored and their temporal evolution characterized.