Rapid at-line analysis of coating thickness and uniformity on tablets using laser induced breakdown spectroscopy

Mowery, Mark D.; Sing, Robert; Kirsch, John D.; Razaghi, Amir; Béchard, Simon; Reed, Robert A.

doi:10.1016/s0731-7085(01)00705-1

Cited by 116 publications

(63 citation statements)

References 21 publications

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“…Mowery et al 283 have utilized the LIBS technique as a rapid means of simultaneously determining the thickness and uniformity of an enteric coating on compressed tablets. The emission spectra of all 4 elements (Ti, Si, Mg and Ca) were simultaneously monitored as a function of the number of laser pulses in the same spatial location.…”

Section: Application To Pharmaceutical Productsmentioning

confidence: 99%

Laser Induced Breakdown Spectroscopy

Pasquini¹,

Cortez²,

Silva³

et al. 2007

J. Braz. Chem. Soc.

342

195

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Esta revisão descreve os aspectos fundamentais, a instrumentação, as aplicações e tendências futuras de uma técnica analítica que se encontra em seu estágio de consolidação e que está em vias de estabelecer o seu nicho entre as técnicas espectrofotométricas modernas. A técnica é denominada Espectroscopia de Emissão em Plasma Induzido por Laser (em inglês, Laser Induced Breakdown Spectroscopy, LIBS) e sua principal característica está no uso de pulsos de laser como fonte de energia para vaporizar a amostra e excitar a emissão de radiação eletromagnética, a partir de seus elementos e/ou fragmentos moleculares. A radiação emitida é analisada por meio de instrumentos ópticos de alta resolução e as suas intensidades são medidas, usualmente com detectores rápidos de estado sólido. Em conjunto, esses dispositivos permitem a geração e a medida de um espectro de emissão de faixa ampla do fenômeno induzido pelo pulso de laser. O espectro registrado contém informação qualitativa e quantitativa que pode ser correlacionada com a identidade da amostra ou empregada na determinação da quantidade de seus constituintes. Essa revisão é dividida em quatro partes. A primeira aborda aspectos históricos da técnica e os conceitos teóricos relevantes associados com LIBS; então, os aspectos práticos de diversas abordagens experimentais e instrumentais empregadas na implementação da técnica são revistos de forma crítica; as aplicações encontradas na literatura, incluindo aquelas que empregam quimiometria, são classificadas e exemplificadas por meio de trabalhos relevantes recentemente publicados. Finalmente, uma tentativa de estabelecer uma avaliação global e as perspectivas futuras para a técnica é apresentada.This review describes the fundamentals, instrumentation, applications and future trends of an analytical technique that is in its early stages of consolidation and is establishing its definitive niches among modern spectrometric techniques. The technique has been named Laser Induced Breakdown Spectroscopy (LIBS) and its main characteristic stands in the use of short laser pulses as the energy source to vaporize samples and excite the emission of electromagnetic radiation from its elements and/or molecular fragments. The emitted radiation is analyzed by high resolution optics and the intensities are recorded, usually by fast triggered solid state detectors. Together, these devices allow producing and registering a wide ranging emission spectrum of the short-lived phenomenon induced by the laser pulse. The spectrum contains qualitative and quantitative information which can be correlated with sample identity or can be used to determine the amount of its constituents. This review is divided in four parts. First, the relevant historical and theoretical concepts associated with LIBS are presented; then the main practical aspects of the several experimental and instrumental approaches employed for implementation of the technique are critically described; the applications related in the literature, including those making use of chemometri...

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Section: Application To Pharmaceutical Productsmentioning

confidence: 99%

Laser Induced Breakdown Spectroscopy

Pasquini¹,

Cortez²,

Silva³

et al. 2007

J. Braz. Chem. Soc.

342

195

View full text Add to dashboard Cite

show abstract

“…Several pharmaceutical applications using LIBS include examples such as the determination of pharmaceutical excipients used in the formulations [10][11][12] quantitative analysis of the drug substance (active pharmaceutical ingredient [API]) in solid dosage forms, 13 determination of magnesium stearate distribution in powder blends, 14,15 tablet coating thickness and uniformity determination of enteric-coated tablets for atline measurements, 16 and effects of physical attributes in LIBS measurement. 17 Mowery et al 16 have illustrated the potential use of LIBS for rapid characterization of film coatings in pharmaceutical products. Film coating is often used in the pharmaceutical solid dosage form for several reasons including protection of the drug from air, moisture and/or light, masking of unpleasant taste, and improvement of product elegance and ease of swallowing.…”

Section: Introductionmentioning

confidence: 99%

Characterization of tablet film coatings using a laser-induced breakdown spectroscopic technique

et al. 2007

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Laser-induced breakdown spectroscopy (LIBS) was evaluated as an early phase process analytical technology (PAT) tool for the rapid characterization of pharmaceutical tablet coatings. Measurement of coating thickness, uniformity, and photodegradation-predictive potential of the technique were evaluated. Model formulation tablets were coated with varying amounts (2%-4% wt/wt) of red and yellow Opadry II, and a pulsed laser was used to sample at multiple sites across the tablet face. LIBS was able to successfully detect the emissions of Fe and Ti in the coated samples, and a proportional increase in signal with coating thickness was observed. Batch-to-batch variability in the coating procedure was also easily monitored by LIBS. The coating thickness was non-uniform across the tablet surface with higher thickness at the edges, likely due to the concave shape of the tablet. Film coating levels and color of the film had been subjected to photostability studies according to the International Conference on Harmonisation (ICH) guideline to determine effectiveness of the film coats. LIBS measurements of coating thickness provided a good correlation (R 2 9 0.99) to photodegradation as measured by high-performance liquid chromatography (HPLC). Last, the concentration of Fe in the coating was varied and monitored by LIBS. Increasing photostability was observed with increasing levels of ferric oxide, providing a new understanding of the photoprotection mechanism in the coated formulation. Determination of levels of ferric oxide and coating thickness by LIBS demonstrated its utility as a good PAT tool for the determination of photoprotection of the drug, thereby enabling facile optimization of the coating process.

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“…The capabilities of LIBS for quantitative elemental analysis have been demonstrated in metallurgy, mining, environmental analysis and numerous other fields [1][2][3][4]. In the pharmaceutical sector, the interest in LIBS has appeared only recently [5][6][7][8][9].…”

Section: Introductionmentioning

confidence: 99%