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Context: Phytomedicines, also known as improved traditional medicines (ITMs), are increasingly used in the management of diseases throughout the world. While quality control widely known to be an essential tool that can ensure the efficacy and safety of health products, most ITMs lack appropriate analytical methods for their control. The aim of this study was to develop a reliable analytical method for the quality control of ITMs commonly used in the Democratic Republic of the Congo (D.R. Congo). For this purpose the method needs to be validated and transferred. Objectives: The objective of this research was to develop, transfer, and validate an affordable, rapid and easily implementable analytical method by HPLC-DAD for the quality control of herbal medicines marketed in the Democratic Republic of the Congo. Also, to determine these drugs fingerprint and their stability under accelerated conditions. Methods: Chromatographic separation was achieved using two chromatographic columns, an XBridge C18 (250 × 4.6 mm i.d.; 5 μm particle size) and an XBridge C18 (100 × 4.6 mm i.d.; 3.5 μm particle size), column maintained at 30 °C. The mobile phase consisted of a gradient mixture of mobile phases A (acetonitrile) and B (aqueous solution of trifluoroacetic acid 0.05%) pumped at 1.0 mL/min. UV detection was performed at 280 nm. The method using the short column was validated using the total extracts as references. The strategy of total error was used to decide on the reliability of the method taking into account the acceptance limits fixed at ± 10%. Results: The validation results show that the developed HPLC-DAD method presented an adequate trueness, linearity, precision and accuracy. Two extra peaks found in the finish products did not interfere with phytomarkers, thus confirming the selectivity of the developed method as appropriate chromatographic profiles. The method was successfully used to determine the content of the phytomarkers in six ITMs. Furthermore, we could notice that the ITMs submitted to the accelerated degradation studies remained chemically stable over six months of harsh treatments. Conclusion: A generic method of analysis of herbal medicines was developed using HPLC-DAD, and subsequently validated before being applied in a stability study of these drugs. The proposed method holds the promise of providing a new tool for quality product development in the field of traditional herbal medicines.

Since 3D printing technology is an emerging field in pharmaceutical technology, the present study aimed at the development of a mixed-mode liquid chromatographic method for the separation and determination of hydrochlorothiazide, diltiazem, and propranolol to investigate their in-vitro release performance from 3D printed tablets. Due to the unique properties of the mixed-mode stationary phase, the three drugs were separated in less than 8 min under isocratic elution. Method development was accomplished following the Analytical Quality by Design principles and was evaluated using risk assessment and multivariate analysis. The influences of critical method parameters on critical method attributes (were screened using a 2-level fractional factorial design and subsequently optimized through a central composite design. The method operable design region was approved by the establishment of a robust zone using Monte Carlo simulation and capability analysis. The validation of the HPLC method was performed based on the total error concept. The relative bias was varied between ─ 11.6 % and 10.5 % and the RSD values for repeatability and intermediate precision were below 4.4 % in all cases. The limits of detection (LOD) ranged between 0.17 – 0.90 μg/mL and were adequate for the specific application. The developed method was successfully applied to the analysis of the studied drugs in in-vitro drug release samples obtained from 3D-printed tablets combining the above-mentioned active pharmaceutical ingredients (APIs). [Display omitted] • Utilization of mixed mode stationary phase for the separation of drugs. • Application of analytical quality by design (AQbD) principles in method development. • Method validation using "total-error" concept. [ABSTRACT FROM AUTHOR]

A salting‐out homogeneous liquid‐liquid microextraction was proposed for the quantification of four azole drugs in human urine prior to high‐performance liquid chromatography analysis. The procedure involved the mixing of the sample with acetonitrile in appropriate volumes followed by the addition of sodium sulfate solution in order to facilitate phase separation. The parameters influencing the extraction performance were studied and optimized using a two‐step experimental design. The analytical procedure was thoroughly validated using the accuracy profiles as a graphical decision‐making tool. The β‐expectation tolerance intervals did not exceed the acceptance criteria of ±15% meaning that 95% of future results will be included in the defined bias limits. The limits of detection of the procedure were satisfactory, ranging between 0.01 and 0.03 μg/mL. The mean analytical bias in the spiking levels was satisfactory and ranged between –10.3 and 4.2% while the relative standard deviation was lower than 5.6%. Monte‐Carlo simulations followed by capability analysis were employed to investigate the ruggedness of the sample preparation protocol. The developed method offers advantages compared to previously reported approaches for the same type of analysis including extraction efficiency and scaling down of the sample volume and extraction time. [ABSTRACT FROM AUTHOR]

Ordinary least squares is widely applied as the standard regression method for analytical calibrations, and it is usually accepted that this regression method can be used for quantification starting at the limit of quantification. However, it requires calibration being homoscedastic and this is not common. Different calibrations have been evaluated to assess whether ordinary least squares is adequate to quantify estimates at low levels. All calibrations evaluated were linear and heteroscedastic. Despite acceptable values for precision at limit of quantification levels were obtained, ordinary least squares fitting resulted in significant and unacceptable bias at low levels. When weighted least squares regression was applied, bias at low levels was solved and accurate estimates were obtained. With heteroscedastic calibrations, limit values determined by conventional methods are only appropriate if weighted least squares are used. A "practical limit of quantification" can be determined with ordinary least squares in heteroscedastic calibrations, which should be fixed at a minimum of 20 times the value calculated with conventional methods. Biases obtained above this "practical limit" were acceptable applying ordinary least squares and no significant differences were obtained between the estimates measured using weighted and ordinary least squares when analyzing real‐world samples. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A UHPLC-DAD method for simultaneous quantification of nicotine and nicotine-related alkaloids in e-liquids was developed. • Fast, robust and very cost-effective quantification method in e-liquids. • The method was successfully validated using accuracy profiles incl. selectivity in presence of e-liquid flavourings. • Method is a suitable alternative to targeted MS/MS-method for routine quality control analyses. Abstract The electronic cigarette (e-cigarette) has emerged as a popular alternative to the traditional hazardous tobacco cigarette. The substantial increase in e-cigarette use also urgently calls for controlling the quality of e-cigarette refill liquid products (e-liquids). Currently, the most important quality indicator of e-liquid products is the quantification of nicotine and its related impurities. Although different methods have been published to measure nicotine and impurity levels, the majority of them use a targeted LC-MS/MS approach. There is, however, a need for more robust quantification methods that are easy to implement in most control (industrial and governmental) laboratories. Therefore, in this study, a simple dilute-and-shoot UHPLC-DAD method has been developed and validated for the simultaneous quantification of nicotine and its alkaloid impurities in electronic cigarette refills. An optimal separation of the alkaloids was achieved in a runtime of 11 min. The method was successfully validated using the "total error" approach in accordance with the validation requirements of ISO-17025. During this validation, interference between the target components and a number of popular flavouring compounds such as vanillin, maltol, ethylacetate, etc. could be excluded. In addition, small changes to the column temperature, pH and molar concentration of the mobile phase buffer were deliberately introduced in order to assess the robustness of the method. Only a slightly different outcome between the newly developed UV-detection method and the targeted MS approach was found, due to the sensitivity of the different detection techniques. However, in the context of quality control of nicotine related impurities, for which the European Pharmacopoeia limits are currently applied, the sensitivity of the UHPLC-DAD method was found to be within the acceptable range. Despite the somewhat lower selectivity of the newly developed UV-detection technique versus a targeted LC-MS/MS approach, it may be concluded that this method is a suitable alternative for quality control purposes. [ABSTRACT FROM AUTHOR]

Abstract Estimations, made by the World Health Organization (WHO), state that 10% of the medical products in low- and middle-income countries are substandard or falsified (SF). Among them, antibiotics and antimalarials are the most commonly reported since 2013. Besides the fact that falsification is a crime, the worldwide use of poor quality antimicrobials could result in treatment failures, stronger antimicrobial resistance and even the promotion of the emergence of superbugs. Therefore, simple and accurate analytical methods are necessary, which are capable to detect and quantify a wide range of antimicrobials in suspected illegal products. In this work, a screening and a quantification method using ultra-high performance liquid chromatography with tandem mass spectrometry (UHPLC-MS2) and diode array detection (UHPLC-DAD), respectively were developed and validated. These methods could be used for routine analysis and enable a more in-depth characterization of SF-antimicrobials. According to their popularity as SF-antimicrobials, 31 antibiotics, 3 antibacterial agents, 1 antifungal agent and 1 beta-lactamase inhibitor, covering eleven different antibacterial classes, were selected. The UHPLC-MS2 screening method with gradient elution is able to selectively detect these 36 compounds within 18 min (including wash and equilibration step). It was validated for sensitivity, selectivity and matrix effects. Within an analysis time of 32 min, the UHPLC-DAD method could quantify 32 compounds (4 showed insufficient UV absorbance) and resulted in sufficient selectivity, necessary since some SF-antimicrobials may include more than one antimicrobial component. This quantification method was validated for the positive hits found during screening tests of suspected illegal samples. This resulted in a validation set of 11 antimicrobials and 1 beta-lactamase inhibitor. The ''total error'' approach in accordance with the validation requirements of ISO-17025 was employed for the validation. 57 real-life illegal samples, seized by inspectors from the Belgium Federal Agency for Medicinal and Health Products (FAMHP), were analyzed using the two described methods. About half of them were not compliant and some samples that contained clavulanic acid showed a serious reduction in the amount of this molecule (in one sample only 14% of the claimed dosage was found). These quality issues might be attributed to either poor manufacturing, storage or transportation conditions. Graphical abstract fx1 Highlights • UHPLC-MS2 screening method for 35 antimicrobials and 1 beta-lactamase inhibitor. • UHPLC-DAD quantification method for 31 antimicrobials and 1 beta-lactamase inhibitor. • Validation of quantification method through accuracy profiles. • 57 illegal antimicrobials were collected from the Belgian market. • Market study showed that half of the collected samples did not comply. [ABSTRACT FROM AUTHOR]

In the present research, a zone fluidics-based automated sensor for the analysis of captopril in in vitro dissolution samples is reported. Captopril is reacted under flow conditions with Ni(II) (10 mmol L−1) in alkaline medium (0.15% v/v NH3) to form a stable derivate, which is monitored spectrophotometrically at 340 nm. The chemical and instrumental parameters were carefully investigated and optimized. The validation of the developed method was performed in the range of 5 to 120% of the expected maximum concentration using the accuracy profiles as a graphical decision-making tool. The β-expectation tolerance intervals did not exceed the acceptance criteria of ±10%, which means that 95% of future results will be encompassed in the defined bias limits. The variation of the relative bias ranged between −2.3% and 3.5% and the RSD values for repeatability and intermediate precision were lower than 2.3% in all cases. The limit of detection (LOD), and the lower and the upper limit of quantification (LLOQ, ULOQ) were satisfactory and found to be 1%, 5% and 120% (corresponding to 0.6, 2.78 and 66.67 μg mL−1 in dissolution medium). The developed method was successfully applied for the analysis of captopril in dissolution tests of two commercially available batches.

This paper aims to present a critical discussion of existing strategies to emphasize possible pitfalls and expected trends that arise from method validation to result assessment. It critically presents some aspects of the three main historical steps, namely terminology, method validation and quality of results. In addition to the formal link between method validation and measurement uncertainty that was recently demonstrated, the abundance of propositions also leads to some problems of consistency. Particular interest is given to the use of tolerance intervals as an appropriate tool to make decisions in method validation, control charts and determination of measurement uncertainty, considering various possibilities regarding adjustments of coverage percentage that can present difficulty for most analytical scientists. [ABSTRACT FROM AUTHOR]

In the research presented we report the development of a simple and robust liquid chromatographic method for the quantification of two genotoxic alkyl sulphonate impurities (namely methyl p -toluenesulfonate and isopropyl p -toluenesulfonate) in Aprepitant API substances using the Analytical Quality by Design (AQbD) approach. Following the steps of AQbD protocol, the selected critical method attributes (CMAs) were the separation criterions between the critical peak pairs, the analysis time and the peak efficiencies of the analytes. The critical method parameters (CMPs) included the flow rate, the gradient slope and the acetonitrile content at the first step of the gradient elution program. Multivariate experimental designs namely Plackett-Burman and Box-Behnken designs were conducted sequentially for factor screening and optimization of the method parameters. The optimal separation conditions were estimated using the desirability function. The method was fully validated in the range of 10–200% of the target concentration limit of the analytes using the “total error” approach. Accuracy profiles − a graphical decision making tool − were constructed using the results of the validation procedures. The β -expectation tolerance intervals did not exceed the acceptance criteria of ± 10%, meaning that 95% of future results will be included in the defined bias limits. The relative bias ranged between − 1.3–3.8% for both analytes, while the RSD values for repeatability and intermediate precision were less than 1.9% in all cases. The achieved limit of detection (LOD) and the limit of quantification (LOQ) were adequate for the specific purpose and found to be 0.02% (corresponding to 48 μg g −1 in sample) for both methyl and isopropyl p -toluenesulfonate. As proof-of-concept, the validated method was successfully applied in the analysis of several Aprepitant batches indicating that this methodology could be used for routine quality control analyses. [ABSTRACT FROM AUTHOR]

Herein, the development of a HILIC method for the determination of imidazole (Imp E) in sildenafil citrate API and its final formulations is reported. The main goal of this study was to develop a robust, application-specific HPLC method according to the Analytical Quality by Design principles for the analysis of the above impurity. After the risk assessment study, the high-risk method parameters were sequentially screened and optimized by using 2-level fractional factorial and Box-Behnken designs. The mathematical models were combined with the Monte-Carlo simulations to identify the Method Operable Design Region. The method was thoroughly validated between 25 % and 150 % of the target concentration limit of the imidazole using the total-error concept. The relative bias varied between 1.6 % and 5.6 % and the RSD values were lower than 5.8 % for repeatability and intermediate precision. The limit of detection and the lower limit of quantification were satisfactory and found to be 0.025 and 0.125 μg mL−1 imidazole, respectively. The applicability of the proposed approach has been demonstrated in the analysis of several sildenafil citrate API batches and final products. [Display omitted] • The first HILIC method for the analysis of imidazole in sildenafil citrate API. • AQbD principles were followed in method development. • Method validation using "total-error" concept. [ABSTRACT FROM AUTHOR]

The simultaneous determination of the monoamines dopamine (DA), noradrenaline (NA) and serotonin (5-HT) in in vivo microdialysis samples remains challenging because of the low extracellular neurotransmitter levels in different brain regions, specific sample characteristics, and the quest for high temporal resolution and a multi-target strategy in neuropharmacological research. A fast and sensitive microbore (1.0 mm i.d. column) UHPLC method coupled to electrochemical detection (ECD) is developed by means of design of experiments with the emphasis on sufficient retention of NA within an acceptable total analysis time. Indeed, NA is the earliest eluting compound and often interferes with the broad solvent front originating from the sample matrix. The sensitive UHPLC-ECD assay (LLOQ of 100 pM for NA and 150 pM for DA and 5-HT) with an analysis time of 8 min for standard solutions and 20 min for in vivo microdialysis samples originating from rat hippocampus, prefrontal cortex and striatum, is validated applying accuracy profiles. The combination of in vivo microdialysis and microbore UHPLC-ECD has shown to be particularly suitable for future contributions to neuropharmacological research on the monoaminergic system. [ABSTRACT FROM AUTHOR]

Poor quality antimalarial drugs are one of the public's major health problems in Africa. The depth of this problem may be explained in part by the lack of effective enforcement and the lack of efficient local drug analysis laboratories. To tackle part of this issue, two spectroscopic methods with the ability to detect and to quantify quinine dihydrochloride in children's oral drops formulations were developed and validated. Raman and near infrared (NIR) spectroscopy were selected for the drug analysis due to their low cost, non-destructive and rapid characteristics. Both of the methods developed were successfully validated using the total error approach in the range of 50–150% of the target concentration (20% W/V) within the 10% acceptance limits. Samples collected on the Congolese pharmaceutical market were analyzed by both techniques to detect potentially substandard drugs. After a comparison of the analytical performance of both methods, it has been decided to implement the method based on NIR spectroscopy to perform the routine analysis of quinine oral drop samples in the Quality Control Laboratory of Drugs at the University of Kinshasa (DRC). [ABSTRACT FROM AUTHOR]

This study focuses on the thorough validation of an in-line NIR based moisture quantification method in the six-segmented fluid bed dryer of a continuous from-powder-to-tablet manufacturing line (ConsiGma™ 25, GEA Pharma Systems nv, Wommelgem, Belgium). The moisture assessment ability of an FT-NIR spectrometer (Matrix™-F Duplex, Bruker Optics Ltd, UK) equipped with a fiber-optic Lighthouse Probe™ (LHP, GEA Pharma Systems nv, Wommelgem, Belgium) was investigated. Although NIR spectroscopy is a widely used technique for in-process moisture determination, a minority of NIR spectroscopy methods is thoroughly validated. A moisture quantification PLS model was developed. Twenty calibration experiments were conducted, during which spectra were collected at-line and then regressed versus the corresponding residual moisture values obtained via Karl Fischer measurements. The developed NIR moisture quantification model was then validated by calculating the accuracy profiles on the basis of the analysis results of independent in-line validation experiments. Furthermore, as the aim of the NIR method is to replace the destructive, time-consuming Karl Fischer titration, it was statistically demonstrated that the new NIR method performs at least as good as the Karl Fischer reference method. [ABSTRACT FROM AUTHOR]

Pentamidine isethionate (PTMD) is an antiprotozoal agent used in different parasitic diseases as Human African Trypanosomiasis or Pneumocystis pneumonia. Given its side effects, numerous analogs are still under development worldwide. PTMD has been recently described having a potential activity in myotonic dystrophy (type 1). Here we present an UPLC method coupled to fluo or PDA detection for PTMD and one analog determination in rat plasma or urine. The chromatographic separation was achieved on a Acquity UPLC® HSS T3 analytical column using a mobile phase combining formic acid 0.1% (v/v) and acetonitrile (ACN) at a constant flow rate of 0.4mL/min. Preliminary, an innovative μSPE (solid phase extraction) procedure using Oasis® WCX sorbent was processed and gave satisfying and reproducible results in terms of extraction yields. Additionally, the methods were successfully validated using the accuracy profiles approach (β =95% and acceptance limits=15%) over the ranges 2.88–287.52ng/mL and from 143.76ng/mL to 1.72μg/mL in rat plasma and urine for PTMD and for EBAB, from 4.23 to 423.39ng/mL and from 211.69ng/mL to 2.54μg/mL for plasma and urine, respectively. The validated protocols were applied to a pharmacokinetic (PK) study on rats and permitted to point out some relevant PK parameters on PTMD and its studied analog. [ABSTRACT FROM AUTHOR]

It is widely accepted that ORAC is a useful method for assessing food extracts that contain various antioxidants. The principal aim of this study was to validate the ORAC assay. We first identified parameters that can interfere with the ORAC assay and we optimized it. Then, experiments were conducted to determine the limits of linearity and response function, to determine the accuracy profiles to circumvent some of the drawbacks of traditional validation procedures. Trueness, selectivity and limits of quantification of the method were also determined. Our objective of ORAC method validation is thus to give guarantees that most of the results generated during use of this method will be close enough to unknown true value of antioxidant capacity of food matrices. The validation results indicate that the described method will give accurate and reliable results for Trolox equivalent values ranging from 50 to 200 μmol/L. [ABSTRACT FROM AUTHOR]

In this article, a UHPLC-PDA method has been developed using the quality-by-design (QbD) principles for the determination of the therapeutic peptide – octreotide – in its in vitro released samples. Due to the complexity of the peptide-based hydrogel matrix a reliable separation of the analyte from the matrix has to be performed. Risk assessment and multivariate analysis were employed for the method evaluation. Following method scouting towards the selection of appropriate and rapid UHPLC operative mode, quality risk assessment tools were applied to set the critical method parameters (CMPs) to be considered in screening phase. The effects of CMPs on critical method attributes (CMAs) were assessed further by means of a screening design. A response surface methodology was utilized to model CMAs as a function of the selected CMPs and the optimum separation conditions were additionally evaluated using desirability function. The method operable design region was complimented by establishment of a robust zone using Monte Carlo simulation and capability analysis. The method was validated in the range of 1 – 20 μg /mL using the accuracy profiles as a graphical decision-making tool. The β -expectation tolerance intervals was within the pre-set acceptance criteria of ± 10% meaning that 95% of future results will be included in the defined bias limits. The relative bias was varied between ─ 0.8% and 1.4% and the RSD values for repeatability and intermediate precision were below to 2.8% in all cases. The achieved limit of detection (LOD) and the lower limit of quantification (LLOQ) were adequate for the specific purpose and found to be 0.3 and 1 μg /mL, respectively. The developed method was successfully applied to the analysis of octreotide in in-vitro drug release samples obtained from peptide-based hydrogels. [Display omitted] • UHPLC determination of octreotide in its in-vitro release samples. • Application of analytical quality by design (AQbD) principles in method development. • Method validation using "total-error" concept. [ABSTRACT FROM AUTHOR]

Abstract: Pharmaceutical counterfeiting is a permanently growing problem. Control laboratories are constantly analysing counterfeit medicines. In industrialised countries, one of the main counterfeited class of medicines are erectile dysfunction drugs. This paper describes the development and validation of a fast method to detect and quantify the three authorised phosphodiesterase type 5 inhibitors and five analogues. The method is based on the use of a sub-2 microns polar-embedded column with a gradient using acetonitrile as organic modifier and 10mM ammonium formate buffer (pH 3.5) as aqueous component of the mobile phase. The separation was achieved in less than 4.5min. The method has also been compared to the registered HPLC method for the assay of Viagra® which was considered as the reference method. The method is also compatible with on-line coupling mass spectrometry and will significantly reduce analysis times and solvent consumption. [Copyright &y& Elsevier]

Abstract: Three novel LC-UV methods for the determination of pentamidine (PTMD) and two of its new analogs in rat plasma are described. The chromatographic conditions (wavelength, acetonitrile percentage in the mobile phase, internal standard) were optimized to have an efficient selectivity. A pre-step of extraction was simultaneously developed for each compound. For PTMD, a solid phase extraction (SPE) with Oasis® HLB cartridges was selected, while for the analogs we used protein precipitation with acetonitrile. SPE for PTMD gave excellent results in terms of extraction yield (99.7±2.8) whereas the recoveries for the analogs were not so high but were reproducible as well (64.6±2.6 and 36.8±1.6 for analog 1 and 2, respectively). By means of a recent strategy based on accuracy profiles (β-expectation tolerance interval), the methods were successfully validated. β was fixed at 95% and the acceptability limits at ±15% as recommended by the FDA. The method was successfully validated for PTMD (29.6–586.54ng/mL), analog 1 (74.23–742.3ng/mL) and analog 2 (178.12–890.6ng/mL). The first concentration level tested was considered as the LLOQ (lower limit of quantification) for PTMD and analog 1 whereas for analog 2, the LLOQ was not the first level tested and was raised to 178.12ng/mL. [ABSTRACT FROM AUTHOR]

[Display omitted] • The proposed HLPME scheme can be easily used in routine bioanalysis. • Sensitive determination of fluoroquinolones in human urine. • Accuracy profiles were implemented for method validation. Miniaturization of liquid-phase extraction is an increasingly emerging field of sample preparation aiming to reduce the solvent consumption and to protect the environment. In this paper, a homogeneous liquid phase microextraction using a hydrophilic extraction media in combination with a salt as phase-forming agent was developed for the determination of four fluoroquinolones (ciprofloxacin, norfloxacin, moxifloxacin and prulifloxacin) in human urine. Important parameters affecting the extraction performance including sample volume, organic solvent volume, salt concentration etc were systematically investigated and optimized. Multivariate experimental designs namely Plackett-Burman and Box-Behnken designs were sequentially applied for factor screening and optimization of the method parameters. The method was fully validated using the "total error" approach. Accuracy profiles – a graphical decision-making tool – were constructed using the results of the validation procedures. The β -expectation tolerance intervals did not exceed the acceptance criteria of ± 15%, meaning that 95% of future results will be included in the defined bias limits. The relative bias ranged between ─ 2.8 to 7.7 % for all analytes, while the RSD values for repeatability and intermediate precision were less 6.6%. The achieved limits of detection (LOD) were ranged between 3 and 11 ng mL−1 while the lower limits of quantitation (LLOQ) were established as 10 ng mL−1 for ciprofloxacin and norfloxacin and 100 ng mL−1 for moxifloxacin and prulifloxacin, respectively. The ruggedness of the microextraction procedure was assessed through Monte-Carlo simulations and capability analysis. The proposed approach improves the procedures proposed to date for the bioanalysis of fluoroquinolones in terms of efficiency, reduction of the sample volume and extraction time. [ABSTRACT FROM AUTHOR]

Abstract: Liquid chromatography (LC) and capillary electrophoresis (CE) methods were developed to perform the determination of residual sodium in mother liquors and successive washes of an active pharmaceutical ingredient (API). The addition of sodium chloride to the product solution results in rapid and complete crystallization of the API. The LC method was coupled to evaporative light scattering detection (ELSD) while the CE approach was based on indirect UV detection. Both methods were fully validated. Selectivity, response function, trueness, precision, accuracy, linearity and limits of detection (LOD) and quantification (LOQ) were the criteria investigated. The LC–ELSD method was found to be more sensitive than the CE/indirect UV approach. The methods were found to be valid over concentration ranges of 62–500 and 235–1500ppm for the LC and the CE methods, respectively. Both methods were compared and used for the determination of actual samples coming from different batches of the same API chemical synthesis. [Copyright &y& Elsevier]

Abstract: Accuracy profiles of chemical assays are introduced and derived from the uncertainty of the analytical result. The calculation of accuracy profiles is based on the estimation of the measurement uncertainty of the analytical assay from validation data. For the sake of illustration, a case study dealing with the spectrofluorimetric determination of quinine in tonic water is explained in detail. [Copyright &y& Elsevier]

In the present research, a zone fluidics-based automated sensor for the analysis of captopril in in vitro dissolution samples is reported. Captopril is reacted under flow conditions with Ni(II) (10 mmol L−1) in alkaline medium (0.15% v/v NH3) to form a stable derivate, which is monitored spectrophotometrically at 340 nm. The chemical and instrumental parameters were carefully investigated and optimized. The validation of the developed method was performed in the range of 5 to 120% of the expected maximum concentration using the accuracy profiles as a graphical decision-making tool. The β-expectation tolerance intervals did not exceed the acceptance criteria of ±10%, which means that 95% of future results will be encompassed in the defined bias limits. The variation of the relative bias ranged between −2.3% and 3.5% and the RSD values for repeatability and intermediate precision were lower than 2.3% in all cases. The limit of detection (LOD), and the lower and the upper limit of quantification (LLOQ, ULOQ) were satisfactory and found to be 1%, 5% and 120% (corresponding to 0.6, 2.78 and 66.67 μg mL−1 in dissolution medium). The developed method was successfully applied for the analysis of captopril in dissolution tests of two commercially available batches. [ABSTRACT FROM AUTHOR]

• Sensitive and fast determination of doxorubicin in human urine. • Toxic solvents free extraction protocol. • Facile applicability for routine analysis. • Accuracy profiles were implemented for method validation. • Satisfactory figures of merit for pharmacokinetic studies. In the present report, a homogeneous liquid liquid extraction using salt as mass separating agent was developed for the determination of the anticancer drug doxorubicin in human urine. Sample preparation is based on the usage of hydrophilic acetonitrile as extraction solvent and its phase separation under high salinity conditions. The analysis of doxorubicin and its epimer, epirubicin, (used as internal standard) was carried out by Ultra High Pressure Liquid Chromatography coupled to fluorimetric detection (λ ex / λ em = 430/580 nm). Total sample analysis was accomplished in less than 15 min including the sample preparation and LC separation steps. The parameters affecting the extraction efficiency and method sensitivity were systematically investigated and optimized using experimental design. The method was validated in-house using the accuracy profiles as a graphical decision-making tool. The β -expectation tolerance intervals did not exceed the acceptance criteria of ± 15% meaning that 95% of future results will be included in the defined bias limits. The limit of detection (LOD) of the method was adequate corresponding to 10 ng mL−1. The mean analytical bias (expressed as relative recoveries) in the spiking levels was acceptable being in the range of 94.7 – 106.3% while the relative standard deviation (RSD) was lower than 5.1%. Experimental designs were built to examine the robustness of the UHPLC method. The proposed method has been satisfactorily applied to the analysis of the selected drug in human urine samples. [ABSTRACT FROM AUTHOR]

• The proposed method can be easily adopted from QC laboratories. • Sensitive determination of hydrazine in allopurinol drug substances. • Accuracy profiles were implemented for method validation. • UHPLC-FL with OPA pre-column derivatization. The present approach poses an interesting way to quantify residues of the genotoxic impurity hydrazine in allopurinol and its pharmaceutical formulations using ultra high performance liquid chromatography coupled to fluorescence detection. Hydrazine was pre-column derivatized through a unique chemistry with o -phthalaldehyde under acidic conditions. Using highly acidic mobile phase the derivative exhibits a strong fluorescence intensity. Derivatization and chromatographic parameters were thoroughly investigated. The validation of the developed method has been carried out in the range of 10 to 200% of the target concentration limit of the analyte using the accuracy profiles as a graphical decision-making tool. The β -expectation tolerance intervals did not exceed the acceptance criteria of ±20% which means that 95% of future results will be included in the defined bias limits. The variation of the relative bias ranged between −6.0 and 0.5% and the RSD values for repeatability and intermediate precision were lower than 6.9% in all cases. The limit of detection (LOD) and the lower limit of quantification (LLOQ) were satisfactory and found to be 0.3 ng mL−1 (corresponding to 0.03 μg g−1 in solid sample). Experimental designs were constructed to study the robustness of the instrumental method and the derivatization procedure. The developed method has been successfully applied for the analysis of hydrazine in allopurinol API batches and tablets indicating that this methodology could be adopted from QC laboratories. [ABSTRACT FROM AUTHOR]

A calibration model for in-line API quantification based on near infrared (NIR) spectra collection during tableting in the tablet press feed frame was developed and validated. First, the measurement set-up was optimised and the effect of filling degree of the feed frame on the NIR spectra was investigated. Secondly, a predictive API quantification model was developed and validated by calculating the accuracy profile based on the analysis results of validation experiments. Furthermore, based on the data of the accuracy profile, the measurement uncertainty was determined. Finally, the robustness of the API quantification model was evaluated. An NIR probe (SentroPAT FO) was implemented into the feed frame of a rotary tablet press (Modul™ P) to monitor physical mixtures of a model API (sodium saccharine) and excipients with two different API target concentrations: 5 and 20% (w/w). Cutting notches into the paddle wheel fingers did avoid disturbances of the NIR signal caused by the rotating paddle wheel fingers and hence allowed better and more complete feed frame monitoring. The effect of the design of the notched paddle wheel fingers was also investigated and elucidated that straight paddle wheel fingers did cause less variation in NIR signal compared to curved paddle wheel fingers. The filling degree of the feed frame was reflected in the raw NIR spectra. Several different calibration models for the prediction of the API content were developed, based on the use of single spectra or averaged spectra, and using partial least squares (PLS) regression or ratio models. These predictive models were then evaluated and validated by processing physical mixtures with different API concentrations not used in the calibration models (validation set). The β-expectation tolerance intervals were calculated for each model and for each of the validated API concentration levels (β was set at 95%). PLS models showed the best predictive performance. For each examined saccharine concentration range (i.e., between 4.5 and 6.5% and between 15 and 25%), at least 95% of future measurements will not deviate more than 15% from the true value., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Pentamidine isethionate (PTMD) is an antiprotozoal agent used in different parasitic diseases as Human African Trypanosomiasis or Pneumocystis pneumonia. Given its side effects, numerous analogs are still under development worldwide. PTMD has been recently described having a potential activity in myotonic dystrophy (type 1). Here we present an UPLC method coupled to fluo or PDA detection for PTMD and one analog determination in rat plasma or urine. The chromatographic separation was achieved on a Acquity UPLC® HSS T3 analytical column using a mobile phase combining formic acid 0.1% (v/v) and acetonitrile (ACN) at a constant flow rate of 0.4 mL/min. Preliminary, an innovative μSPE (solid phase extraction) procedure using Oasis® WCX sorbent was processed and gave satisfying and reproducible results in terms of extraction yields. Additionally, the methods were successfully validated using the accuracy profiles approach (β=95% and acceptance limits=15%) over the ranges 2.88-287.52 ng/mL and from 143.76 ng/mL to 1.72 μg/mL in rat plasma and urine for PTMD and for EBAB, from 4.23 to 423.39 ng/mL and from 211.69 ng/mL to 2.54 μg/mL for plasma and urine, respectively. The validated protocols were applied to a pharmacokinetic (PK) study on rats and permitted to point out some relevant PK parameters on PTMD and its studied analog., (Copyright © 2014 Elsevier B.V. All rights reserved.)