Detection of Lipitor® counterfeits: A comparison of NIR and Raman spectroscopy in combination with chemometrics

DoE Screening and Optimization of Liquid Chromatographic Determination of Nicotinic Acid and Six Statins: Application to Pharmaceutical Preparations and Counterfeit Detection

An isocratic reversed-phase high performance liquid chromatographic method has been developed and validated to simultaneously determine nicotinic acid, pravastatin sodium, rosuvastatin calcium, atorvastatin calcium, pitavastatin calcium, lovastatin sodium and simvastatin sodium in focus on counterfeit drug detection. Thin-layer chromatography, nuclear magnetic resonance and mass spectrometry have been additionally performed to verify the identification of adulterants of counterfeit herbal medicines. Chromatographic separation was carried out on Inertsil® ODS-3 C18 (4.6 × 150 mm, 5 μm) with isocratic mobile phase elution containing a mixture of acetonitrile: methanol: 25 mM potassium dihydrogen phosphate buffer, pH 2.86 adjusted with 0.1 M o-phosphoric acid (48: 30: 22, v/v/v), at a flow rate of 1 mL/min and with UV detection at 238 nm. The design of experiment methodology, Plackett-Burman and Box-Behnken designs, was used to screen and optimize the mobile phase composition. The validation of the method was also carried out under the International Conference on Harmonization guidelines. The developed method was sensitive, accurate, simple, economical and highly robust, in addition to the comprehensiveness and novelty of this method for separating the seven drugs. The results were statistically compared with the reference methods used Student's t-test and variance ratio F-test at P < 0.05.

A Review of Pharmaceutical Robot based on Hyperspectral Technology

The quality and safety of medicinal products are related to patients’ lives and health. Therefore, quality inspection takes a key role in the pharmaceutical industry. Most of the previous solutions are based on machine vision, however, their performance is limited by the RGB sensor. The pharmaceutical visual inspection robot combined with hyperspectral imaging technology is becoming a new trend in the high-end medical quality inspection process since the hyperspectral data can provide spectral information with spatial knowledge. Yet, there is no comprehensive review about hyperspectral imaging-based medicinal products inspection. This paper focuses on the pivotal pharmaceutical applications, including counterfeit drugs detection, active component analysis of tables, and quality testing of herbal medicines and other medical materials. We discuss the technology and hardware of Raman spectroscopy and hyperspectral imaging, firstly. Furthermore, we review these technologies in pharmaceutical scenarios. Finally, the development tendency and prospect of hyperspectral imaging technology-based robots in the field of pharmaceutical quality inspection is summarized.

A NIR, 1H-NMR, LC-MS and chemometrics pilot study on the origin of carvedilol drug substances: a tool for discovering falsified active pharmaceutical ingredients

Falsification of drugs, entailing the use of drug substances from unknown unapproved suppliers, is one of the main concerns for the quality of medicines. Therefore, traceability of active ingredients represents an effective tool to fight the illegal trade of medicinal products. In this view, the present pilot study explores the profile of carvedilol active ingredients and possible differences related to the origin. Sixteen samples were examined by near-infrared spectroscopy (NIR), proton nuclear magnetic resonance (¹H-NMR spectrometry) and liquid chromatography mass spectrometry (LC-MS) Q-TOF and the data were analysed by principal component analysis (PCA), cluster analysis and PLSDA discriminant analysis. The results evidenced that the combined information from the three techniques gave good classification of the samples neatly distinguishing the APIs from European countries from the APIs manufactured out of Europe. In particular, NIR spectroscopy provided effective separation between European and non-European manufacturers and ¹H-NMR or LC-MS added specific information related to the separation. Concerning LC-MS Q-TOF, the analysis of multiple isobaric peaks proved to be highly predictive of the drug substance origin and emerged as a promising tool in the field of medicine traceability.

Discrimination of Falsified Erectile Dysfunction Medicines by Use of an Ultra-Compact Raman Scattering Spectrometer

Substandard and falsified medicines are often reported worldwide. An accurate and rapid detection method for falsified medicines is needed to prevent human health hazards. Raman scattering spectroscopy has emerged as a non-destructive analysis method for the detection of falsified medicines. In this laboratory study, Raman spectroscopy was performed to evaluate the applicability of the ultra-compact Raman scattering spectrometer (C13560). Principal component analysis (PCA) was also performed on the Raman spectra. This study analyzed tadalafil (Cialis), vardenafil (Levitra), and sildenafil (Viagra) tablets. We tested the standard product and products purchased from the internet (genuine or falsified). For Cialis and Levitra, all falsified tablets were identified by the Raman spectra and PCA score plot. For Viagra, the Raman spectra of some falsified tablets were almost comparable to the standard tablet. The PCA score plots of falsified tablets were dispersed, and some plots of falsified tablets were close to the standard tablet. In conclusion, C13560 was useful for the discrimination of falsified Cialis and Levitra tablets, whereas some falsified Viagra tablets had Raman spectra similar to that of the standard tablet. The development of detection methods that can be introduced in various settings may help prevent the spread of falsified products.

Super-capacity information-carrying systems encoded with spontaneous Raman scattering

Optical multiplex barcode systems have been significantly boosting the throughput of scientific discovery. A high volume of barcodes can be made from combinations of distinct spectral bands and intensity levels. However, the practical capacity often reaches a ceiling due to the overlaps of signal frequencies or intensities when massive information is written on individual carriers. In this paper, we built super-capacity information-carrying systems by tuning vibrational signals into octal numeral intensities in multiple bands of Raman-silent regions. This novel approach experimentally yielded the largest capacity of distinct optical barcodes to date. The experiments of encoding ASCII and Unicode systems to write and read languages indicate that the Raman coding method provides a new strategy for super-capacity data storage. In addition, multiplex screening of a cell-binding ligand was implemented to demonstrate the feasibility of this technology for fast and in situ high-throughput bio-discovery. These information-carrying systems may open new scenarios for the development of high-throughput screening, diagnostics and data storage.

Super-capacity information-carrying systems are fabricated by tuning vibrational signals into octal numeral intensities in multiple bands of Raman-silent regions.

Chemometric Methods for Spectroscopy-Based Pharmaceutical Analysis

Spectroscopy is widely used to characterize pharmaceutical products or processes, especially due to its desirable characteristics of being rapid, cheap, non-invasive/non-destructive and applicable both off-line and in-/at-/on-line. Spectroscopic techniques produce profiles containing a high amount of information, which can profitably be exploited through the use of multivariate mathematic and statistic (chemometric) techniques. The present paper aims at providing a brief overview of the different chemometric approaches applicable in the context of spectroscopy-based pharmaceutical analysis, discussing both the unsupervised exploration of the collected data and the possibility of building predictive models for both quantitative (calibration) and qualitative (classification) responses.

Survey to Identify Substandard and Falsified Tablets in Several Asian Countries with Pharmacopeial Quality Control Tests and Principal Component Analysis of Handheld Raman Spectroscopy

The World Health Organization has warned that substandard and falsified medical products (SFs) can harm patients and fail to treat the diseases for which they were intended, and they affect every region of the world, leading to loss of confidence in medicines, health-care providers, and health systems. Therefore, development of analytical procedures to detect SFs is extremely important. In this study, we investigated the quality of pharmaceutical tablets containing the antihypertensive candesartan cilexetil, collected in China, Indonesia, Japan, and Myanmar, using the Japanese pharmacopeial analytical procedures for quality control, together with principal component analysis (PCA) of Raman spectrum obtained with handheld Raman spectrometer. Some samples showed delayed dissolution and failed to meet the pharmacopeial specification, whereas others failed the assay test. These products appeared to be substandard. Principal component analysis showed that all Raman spectra could be explained in terms of two components: the amount of the active pharmaceutical ingredient and the kinds of excipients. Principal component analysis score plot indicated one substandard, and the falsified tablets have similar principal components in Raman spectra, in contrast to authentic products. The locations of samples within the PCA score plot varied according to the source country, suggesting that manufacturers in different countries use different excipients. Our results indicate that the handheld Raman device will be useful for detection of SFs in the field. Principal component analysis of that Raman data clarify the difference in chemical properties between good quality products and SFs that circulate in the Asian market.

Reduction of interferences in the analysis of Children's Dimetapp using ultraviolet spectroscopy data and target factor analysis

A calibration matrix has been developed and successfully applied to quantify actives in Children's Dimetapp®, a cough mixture whose active components suffer from heavy spectral interference. High-performance liquid chromatography/photodiode array instrument was used to identify the actives and any other UV-detectable excipients that might contribute to interferences. The instrument was also used to obtain reference data on the actives, instead of relying on the manufacturer's claims. Principal component analysis was used during the developmental stages of the calibration matrix to highlight any mismatch between the calibration and sample spectra, making certain that "apples" were not compared with "oranges". The prediction model was finally calculated using target factor analysis and partial least squares regression. In addition to the actives in Children's Dimetapp® (brompheniramine maleate, phenylephrine hydrogen chloride, and dextromethorphan hydrogen bromide), sodium benzoate was identified as the major and FD&C Blue #1, FD&C Red #40, and methyl anthranilate as minor spectral interferences. Model predictions were compared before and after the interferences were included into the calibration matrix. Before including interferences, the following results were obtained: brompheniramine maleate=481.3mgL^-1±134% RE; phenylephrine hydrogen chloride=1041mgL^-1±107% RE; dextromethorphan hydrogen bromide=1571mgL^-1±107% RE, where % RE=percent relative error based on the reference HPLC data. After including interferences, the results were as follows: brompheniramine maleate=196.3mgL^-1±4.4% RE; phenylephrine hydrogen chloride=501.3mgL^-1±0.10% RE; dextromethorphan hydrogen bromide=998.7mgL^-1±1.6% RE as detailed in Table 6.

Infrared spectroscopy and spectroscopic imaging in forensic science

Infrared spectroscopy and spectroscopic imaging, are robust, label free and inherently non-destructive methods with a high chemical specificity and sensitivity that are frequently employed in forensic science research and practices. This review aims to discuss the applications and recent developments of these methodologies in this field. Furthermore, the use of recently emerged Fourier transform infrared (FT-IR) spectroscopic imaging in transmission, external reflection and Attenuated Total Reflection (ATR) modes are summarised with relevance and potential for forensic science applications. This spectroscopic imaging approach provides the opportunity to obtain the chemical composition of fingermarks and information about possible contaminants deposited at a crime scene. Research that demonstrates the great potential of these techniques for analysis of fingerprint residues, explosive materials and counterfeit drugs will be reviewed. The implications of this research for the examination of different materials are considered, along with an outlook of possible future research avenues for the application of vibrational spectroscopic methods to the analysis of forensic samples.

Classification and Visualization of Physical and Chemical Properties of Falsified Medicines with Handheld Raman Spectroscopy and X-Ray Computed Tomography

Analytical methods for the detection of substandard and falsified medical products (SFs) are important for public health and patient safety. Research to understand how the physical and chemical properties of SFs can be most effectively applied to distinguish the SFs from authentic products has not yet been investigated enough. Here, we investigated the usefulness of two analytical methods, handheld Raman spectroscopy (handheld Raman) and X-ray computed tomography (X-ray CT), for detecting SFs among oral solid antihypertensive pharmaceutical products containing candesartan cilexetil as an active pharmaceutical ingredient (API). X-ray CT visualized at least two different types of falsified tablets, one containing many cracks and voids and the other containing aggregates with high electron density, such as from the presence of the heavy elements. Generic products that purported to contain equivalent amounts of API to the authentic products were discriminated from the authentic products by the handheld Raman and the different physical structure on X-ray CT. Approach to investigate both the chemical and physical properties with handheld Raman and X-ray CT, respectively, promise the accurate discrimination of the SFs, even if their visual appearance is similar with authentic products. We present a decision tree for investigating the authenticity of samples purporting to be authentic commercial tablets. Our results indicate that the combination approach of visual observation, handheld Raman and X-ray CT is a powerful strategy for nondestructive discrimination of suspect samples.

Chemometrics and the identification of counterfeit medicines-A review

This review article provides readers with a number of actual case studies dealing with verifying the authenticity of selected medicines supported by different chemometric approaches. In particular, a general data processing workflow is discussed with the major emphasis on the most frequently selected instrumental techniques to characterize drug samples and the chemometric methods being used to explore and/or model the analytical data. However, further discussion is limited to a situation in which the collected data describes two groups of drug samples - authentic ones and counterfeits.

Noninvasive liver diseases detection based on serum surface enhanced Raman spectroscopy and statistical analysis

In this paper, we investigated the feasibility of using surface enhanced Raman spectroscopy (SERS) of blood serum to discriminate liver cancer and liver cirrhosis patients from normal people. Serum taken from 44 healthy people, 45 liver cancer patients, 42 post-treatment liver cancer patients and 45 liver cirrhosis patients was measured. SERS peaks from these groups were compared and the assignments and biomedical meanings were analyzed and explained. In addition, support vector machine (SVM), partial least square-discriminant analysis (PLS-DA) and artificial neural networks (ANN) was used on the obtained SERS spectra to identify its diagnostic potential for liver diseases. PLS-SVM, PLS-DA and PLS-ANN indicated 91.5%, 89.2% and 90.3% accuracy, respectively. This preliminary study demonstrates that serum SERS can be used for liver cancer screening.

Determination of counterfeit medicines by Raman spectroscopy: Systematic study based on a large set of model tablets

In the last decade, counterfeit pharmaceutical products have become a widespread issue for public health. Raman spectroscopy which is easy, non-destructive and information-rich is particularly suitable as screening method for fast characterization of chemicals and pharmaceuticals. Combined with chemometric techniques, it provides a powerful tool for the analysis and determination of counterfeit medicines. Here, for the first time, a systematic study of the benefits and limitations of Raman spectroscopy for the analysis of pharmaceutical samples on a large set of model tablets, varying with respect to chemical and physical properties, was performed. To discriminate between the different mixtures, a combination of dispersive Raman spectroscopy performing in backscattering mode and principal component analysis was used. The discrimination between samples with different coatings, a varying amount of active pharmaceutical ingredients and a diversity of excipients were possible. However, it was not possible to distinguish between variations of the press power, mixing quality and granulation. As a showcase, the change in Raman signals of commercial acetylsalicylic acid effervescent tablets due to five different storage conditions was monitored. It was possible to detect early small chemical changes caused by inappropriate storage conditions. These results demonstrate that Raman spectroscopy combined with multivariate data analysis provides a powerful methodology for the fast and easy characterization of genuine and counterfeit medicines.

Batch-specific discrimination using nuclear quadrupole resonance spectroscopy

In this paper, we report on the identification of batches of analgesic paracetamol (acetaminophen) tablets using nitrogen-14 nuclear quadrupole resonance spectroscopy ((14)N NQR). The high sensitivity of NQR to the electron charge distribution surrounding the quadrupolar nucleus enables the unique characterization of the crystal structure of the material. Two hypothesis were tested on batches of the same brand: the within the same batch variability and the difference between batches that varied in terms of their batch number and expiry date. The multivariate analysis of variance (MANOVA) did not provide any within-batches variations, indicating the natural deviation of a medicine manufactured under the same conditions. Alternatively, the statistical analysis revealed a significant discrimination between the different batches of paracetamol tablets. Therefore, the NQR signal is an indicator of factors that influence the physical and chemical integrity of the material. Those factors might be the aging of the medicine, the manufacturing, or storage conditions. The results of this study illustrate the potential of NQR as promising technique in applications such as detection and authentication of counterfeit medicines.

Evaluation of vibrational spectroscopic methods to identify and quantify multiple adulterants in herbal medicines

To counter the growth of herbal medicines adulterated with pharmaceuticals crossing borders, rapid, inexpensive and non-destructive analytical techniques, that can handle complex matrices, are required. Since mid-infrared (MIR), near infrared (NIR) and Raman spectroscopic techniques meet these criteria, their performance in identifying adulterants in seized weightloss herbal medicines is definitively determined. Initially a validated high pressure liquid chromatography methodology was used for reference identification and quantification of the adulterants sibutramine H2O·HCl, fenfluramine HCl and phenolphthalein. Of 38 products, only sibutramine and phenolphthalein were detected by HPLC. The spectroscopic measurements showed Raman was ill-suited due to sample burning and emission while NIR lacked adulterant selectivity. Conversely, MIR demonstrated apt identification performance, which manifested as spectrally meaningful separation based on the presence and type of adulterant during principal component analysis (test set validated). Partial least squares regression models were constructed from the MIR training sets for sibutramine and phenolphthalein - both models fitted the training set data well. Average test set prediction errors were 0.8% for sibutramine and 2.2% for phenolphthalein over the respective concentration ranges of 1.7-11.7% and 0.9-34.4%. MIR is apposite for the screening of anorectic and laxative adulterants and is the most viable technique for wider adulterant screening in herbal medicines.

Rapid screening of anti-infective drug products for counterfeits using Raman spectral library-based correlation methods

A new spectral library-based approach that is capable of screening a diverse set of finished drug products using only an active pharmaceutical ingredient spectral library is described in this paper.

Identification of anisodamine tablets by Raman and near-infrared spectroscopy with chemometrics

Vibrational spectroscopy including Raman and near-infrared (NIR) spectroscopy has become an attractive tool for pharmaceutical analysis. In this study, effective calibration models for the identification of anisodamine tablet and its counterfeit and the distinguishment of manufacturing plants, based on Raman and NIR spectroscopy, were built, respectively. Anisodamine counterfeit tablets were identified by Raman spectroscopy with correlation coefficient method, and the results showed that the predictive accuracy was 100%. The genuine anisodamine tablets from 5 different manufacturing plants were distinguished by NIR spectroscopy using partial least squares discriminant analysis (PLS-DA) models based on interval principal component analysis (iPCA) method. And the results showed the recognition rate and rejection rate were 100% respectively. In conclusion, Raman spectroscopy and NIR spectroscopy combined with chemometrics are feasible and potential tools for rapid pharmaceutical tablet discrimination.

Understanding and fighting the medicine counterfeit market

Medicine counterfeiting is a serious worldwide issue, involving networks of manufacture and distribution that are an integral part of industrialized organized crime. Despite the potentially devastating health repercussions involved, legal sanctions are often inappropriate or simply not applied. The difficulty in agreeing on a definition of counterfeiting, the huge profits made by the counterfeiters and the complexity of the market are the other main reasons for the extent of the phenomenon. Above all, international cooperation is needed to thwart the spread of counterfeiting. Moreover effort is urgently required on the legal, enforcement and scientific levels. Pharmaceutical companies and agencies have developed measures to protect the medicines and allow fast and reliable analysis of the suspect products. Several means, essentially based on chromatography and spectroscopy, are now at the disposal of the analysts to enable the distinction between genuine and counterfeit products. However the determination of the components and the use of analytical data for forensic purposes still constitute a challenge. The aim of this review article is therefore to point out the intricacy of medicine counterfeiting so that a better understanding can provide solutions to fight more efficiently against it.

Assessment of the performance of a handheld Raman device for potential use as a screening tool in evaluating medicines quality

The TruScan(®) handheld Raman device is used for testing finished pharmaceutical products in the field to detect counterfeit and substandard medicines. Present work reports on the device's ability to discriminate between a specific product and similar products from different manufacturers, unrelated medicines, and medicines with different strengths. This investigation evaluated its ability to differentiate between similar drug products of similar or different strengths, focusing on the specificity and precision of the testing. First, several units of the same medicine's dosage form were compared; then comparisons were made between unrelated products, similar products, and products with different strengths. The six pharmaceutical products used in testing were from commonly used analgesic, antimalarial, and antidiarrheal medicines. The results showed that the performance of the TruScan(®) device depends on the nature and the strength of the dosage form tested; while the device could be suitable for authentication of some finished pharmaceutical products and, hence, could be used to detect some counterfeit medicines, it could not be used to detect substandard medicines. Careful consideration should be given when using the device as a screening tool for counterfeit medicines.

Detection and chemical profiling of medicine counterfeits by Raman spectroscopy and chemometrics

Raman spectroscopy combined with chemometrics has recently become a widespread technique for the analysis of pharmaceutical solid forms. The application presented in this paper is the investigation of counterfeit medicines. This increasingly serious issue involves networks that are an integral part of industrialized organized crime. Efficient analytical tools are consequently required to fight against it. Quick and reliable authentication means are needed to allow the deployment of measures from the company and the authorities. For this purpose a method in two steps has been implemented here. The first step enables the identification of pharmaceutical tablets and capsules and the detection of their counterfeits. A nonlinear classification method, the Support Vector Machines (SVM), is computed together with a correlation with the database and the detection of Active Pharmaceutical Ingredient (API) peaks in the suspect product. If a counterfeit is detected, the second step allows its chemical profiling among former counterfeits in a forensic intelligence perspective. For this second step a classification based on Principal Component Analysis (PCA) and correlation distance measurements is applied to the Raman spectra of the counterfeits.

Comparison of UHPLC and HPLC methods for the assay of prostanoids: "are the methods equivalent in terms of accuracy and precision?"

BACKGROUND

As new methods are developed to increase efficiency and higher analytical performance, it is necessary to evaluate their quality in comparison to standard methods. To understand how the analytical performance changes between methods, it is common to compare the validation parameters; sensitivity, linearity, accuracy and precision. Here, we compare an UHPLC-UV method to the HPLC-UV method (reference method) for the simultaneous determination of seven prostanoids. Though the basic chromatography theory is the same for HPLC and UHPLC, the instrumentation has been modified to accommodate higher pressures, lower flow rates and smaller sample size. The differences in analytical instrumentation and procedures can give rise to method inequivalencies. Our approach evaluates the UHPLC and HPLC methods and poses the question: are the methods equivalent? To answer this question a statistical comparison of the analytical performance and method parameters is necessary.

RESULTS

Statistical comparisons were performed using the t-test, F-test, regression analyses (ordinary linear regression and Deming regression) and Bland-Altman analyses. Statistical comparison of the results, suggested that the precision (amount of variability) is different (p < 0.05) for the HPLC and UHPLC methods. Whereas, the accuracy (method bias and the means) is similar (p > 0.05) for 8-isoprostane, 11-dehydro TXB₂, PGE₂ PGF(2α), PGD₂ and 15-deoxy Δ¹²,¹⁴ PGJ₂.

DISCUSSION

Ordinary linear regression shows that the methods are well correlated for all compounds. The Deming regression, which assumes error in both the methods, suggests the existence of a proportional and constant bias for 11-dehydro TXB₂ and only proportional bias for 8-isoprostane, PGF(2α), PGD₂ and 15-deoxy Δ(12,14) PGJ₂ between the two methods. According to Deming regression, the two methods are statistically similar for 6-keto PGF(1α) and PGE₂. The Bland-Altman analyses indicate the two methods are commutable.

Reliable low-cost capillary electrophoresis device for drug quality control and counterfeit medicines

The proportion of counterfeit medicines is dramatically increasing these last few years. According to numerous official sources, in some pharmaceutical wholesalers in African countries, the proportion has reached 80%. Unfortunately, this situation is far to be improved due to lack of suitable analytical equipment allowing rapid actions of the Regulatory Agencies based on scientific consideration, at affordable cost and all over the drug supply chain. For that purpose, a network group considered that mater by building a low-cost original capillary electrophoresis (CE) equipment equipped with a new deep UV detector based on LED technology. The generic conditions for analysis were investigated: capillary zone electrophoresis (CZE) performed at acidic pH for basic drug molecules (i.e., quinine, highly used as the last antimalarial rampart), basic pH for compounds such as furosemide (a common diuretic drug) and at neutral pH for a well known antibiotic combination, trimethoprim/sulfamethoxazol. To evaluate the ability of the CE equipment for quantification, a full validation and a method comparison study were carried out for the CZE method dedicated to quinine determination. The validation involved the use of accuracy profile and total error concept to monitor the adequacy of the results obtained by the new prototype. The method comparison was based on the Bland and Altman approach by comparing results obtained by the low-cost CE and a conventional set-up. Subsequent validation studies were realized with neutral and acidic drug molecules, each focusing on a single concentration level calibration curve in order to maintain as low as possible the expenses due to reagents and thus the cost of analysis, as important advantages of CE for drug quality control.

Discerning some Tylenol brands using attenuated total reflection Fourier transform infrared data and multivariate analysis techniques

Principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were used to classify acetaminophen-containing medicines using their attenuated total reflection Fourier transform infrared (ATR-FT-IR) spectra. Four formulations of Tylenol (Arthritis Pain Relief, Extra Strength Pain Relief, 8 Hour Pain Relief, and Extra Strength Pain Relief Rapid Release) along with 98% pure acetaminophen were selected for this study because of the similarity of their spectral features, with correlation coefficients ranging from 0.9857 to 0.9988. Before acquiring spectra for the predictor matrix, the effects on spectral precision with respect to sample particle size (determined by sieve size opening), force gauge of the ATR accessory, sample reloading, and between-tablet variation were examined. Spectra were baseline corrected and normalized to unity before multivariate analysis. Analysis of variance (ANOVA) was used to study spectral precision. The large particles (35 mesh) showed large variance between spectra, while fine particles (120 mesh) indicated good spectral precision based on the F-test. Force gauge setting did not significantly affect precision. Sample reloading using the fine particle size and a constant force gauge setting of 50 units also did not compromise precision. Based on these observations, data acquisition for the predictor matrix was carried out with the fine particles (sieve size opening of 120 mesh) at a constant force gauge setting of 50 units. After removing outliers, PCA successfully classified the five samples in the first and second components, accounting for 45.0% and 24.5% of the variances, respectively. The four-component PLS-DA model (R(2)=0.925 and Q(2)=0.906) gave good test spectra predictions with an overall average of 0.961 +/- 7.1% RSD versus the expected 1.0 prediction for the 20 test spectra used.

Counterfeit drugs detection by measurement of tablets and secondary packaging colour

The growth of pharmaceutical counterfeiting is a major public health problem. This growth is resulting in a proportional increase in the number of samples that medicines control laboratories have to test. Thus the need for simple and affordable preliminary screening methods to be used by inspectors to decide in the field whether to collect a sample for further laboratory analysis or not. This paper intends to evaluate the possibility to employ for preliminary examinations of suspicious samples an optical spectrophotometer (colorimeter) used in the graphic industry, capable of measuring the reflectance visible spectrum of solid materials. The colorimeter was tested on original and counterfeited Viagra, Cialis and Levitra by measuring the colour of tablets' surface and of a specific spot of the packages. Various batches of the original drugs were employed both to investigate precision and robustness of the technique and to build spectral libraries. These libraries were used to compare suspicious samples to the corresponding original by means of a wavelength distance pattern recognition method. The method was eventually tested on suspicious samples sized by police authorities in order to evaluate its effectiveness. The device resulted precise and robust toward ambient conditions changes, although some limits emerged: the libraries of original samples need a frequent update and a lower precision is to be expected for tablets which surface is extremely convex.

Ibuprofen-loaded calcium phosphate granules: combination of innovative characterization methods to relate mechanical strength to drug location

This paper studies the impact of the location of a drug substance on the physicochemical and mechanical properties of two types of calcium phosphate granules loaded with seven different contents of ibuprofen, ranging from 1.75% to 46%. These implantable agglomerates were produced by either low or high shear granulation. Unloaded Mi-Pro pellets presented higher sphericity and mechanical properties, but were slightly less porous than Kenwood granules (57.7% vs 61.2%). Nevertheless, the whole expected quantity of ibuprofen could be integrated into both types of granules. A combination of surface analysis, using near-infrared (NIR) spectroscopy coupling chemical imaging, and pellet porosity, by mercury intrusion measurements, allowed ibuprofen to be located. It was shown that, from 0% to 22% drug content, ibuprofen deposited simultaneously on the granule surface, as evidenced by the increase in surface NIR signal, and inside the pores, as highlighted by the decrease in pore volume. From 22%, porosity was almost filled, and additional drug substance coated the granule surfaces, leading to a large increase in the surface NIR signal. This coating was more regular for Mi-Pro pellets owing to their higher sphericity and greater surface deposition of drug substance. Unit crush tests using a microindenter revealed that ibuprofen loading enhanced the mechanical strength of granules, especially above 22% drug content, which was favorable to further application of the granules as a bone defect filler.

Near-infrared chemical imaging (NIR-CI) for counterfeit drug identification--a four-stage concept with a novel approach of data processing (Linear Image Signature)

A new stage concept was developed to reliably identify counterfeit tablets which are very similar to the genuine drug product. This concept combines single-point near-infrared spectroscopy (NIRS) and near-infrared chemical imaging (NIR-CI) with statistical variance analysis. The advantage of NIR-CI over NIRS is the potential to determine not only the amount, but also the spatial distribution of ingredients within a single tablet. Previously published NIR-CI studies used homogeneity as a key indicator for the identification of counterfeits. The state of the art approach for estimating homogeneity is to record the average and % standard deviation of predicted classification scores (i.e. concentrations) for a given component within a specimen. A disadvantage of this approach is the partial loss of spatial information. In view of this, we developed a new method using much more of the spatial information for the estimation of homogeneity. The method is based on (1) summation and unfolding of multidimensional predicted classification scores, which results in a Linear Image Signature (LIS) and (2) multivariate LIS data analysis (LIS-MVA). It could be demonstrated that this kind of NIR-CI data analysis represents an innovative approach for the identification of counterfeit tablets. Moreover, this procedure is applicable to determine the product variability, i.e. process signature of a given product thus being a valuable tool within the Quality by Design (QbD) approach of the ICH Q8 guideline.