Its broad applicability and capacity to separate numerous components in a single chromatographic run led to the initial recognition of RP-HPLC as an analytical technique. The objective of this study was to create a straightforward and reliable method for accurately and precisely measuring the amount of Tapinarof in both the topical formulation and the active pharmaceutical ingredient. Additionally, a robust high performance liquid chromatography (HPLC) assay was developed specifically for analyzing the topical formulation. In this study, chromatographic analysis was conducted using a Kromosil C18 column with dimensions of 250 × 4.6 mm and a particle size of 5 microns. The mobile phase consisted of a phosphate buffer and methanol in a ratio of 100:900 (v/v). The flow rate was set at 1.0 mL/min, with an injection volume of 10 µL and a run time of 6 minutes using isocratic elution. UV detection was performed at a wavelength of 313 nm, and the temperature was maintained at 30 °C. The analysis showed well-separated peaks with a high number of theoretical plates, a low tailing factor, and consistent retention time. Validation of the method was conducted, and all validation parameters were found to be within the acceptable limits. A method that is simple, accurate, and precise has been developed to estimate the amount of Tapinarof in a topical formulation and active pharmaceutical ingredient. The optimized method involved the use of a column temperature set at 30 °C, 90% methanol as the mobile phase, and a flow rate of 1.0 mL/min. The retention time for Tapinarof was determined to be 2.88 minutes. The method exhibited linearity in the concentration range of 5 to 30 µg/mL (with an R2 value greater than 0.999) for Tapinarof. The topical formulated cream and active pharmaceutical ingredient showed more than 90% dissolution within 5 minutes. The method developed in this study utilized PDA for peak integrity and purity confirmation, making it suitable for the quantification of Tapinarof in both topical formulations and active pharmaceutical ingredients. The method was validated and can be recommended for routine analysis in quality control laboratories.

In 2019, the FDA approved a brand-new combination of linagliptin and empagliflozin in a formulation called Glyxambi® tablets for managing type-2 diabetes mellitus. Nowadays, spectrophotometric techniques occupy the first place among their peers in terms of ease of application, friendliness to the environment, and low costs. This research discusses the development of two very simple spectrophotometric protocols based on zero-order spectra for the determination of linagliptin and empagliflozin. The developed protocols were the induced dual-wavelength and absorption correction protocols. Linagliptin could be determined directly at 305 nm, at which the empagliflozin spectrum was zero-crossing. Empagliflozin was determined using the developed two protocols. The induced dual-wavelength technique was developed by calculating the equality factor of linagliptin to cancel its interference. The absorption correction technique was developed by measuring the correction absorption factor. The concentration ranges of linagliptin and empagliflozin were (1-10) µg/mL and (3-30) µg/mL, respectively. Excellent recovery results were found in bulk, dosage form, and synthetic mixtures. Low LOD and LOQ values were obtained, indicating the high sensitivity of the protocols. The statistical student's t-test was performed to compare the results of the applied and reported protocols, indicating no difference between them. The proposed protocols have the advantages of being straightforward, affordable, and requiring no sophisticated manipulations, just simple mathematical calculations. The proposed protocols are acceptable for routine usage in quality control laboratories and in future research applications. Two novel univariate methods were developed for quantitative analysis of linagliptin and empagliflozin in their pharmaceutical and lab mixtures, producing satisfactory results.

Cannabis sativa is known to produce a class of terpenophenolic compounds named cannabinoids. The two main ones are cannabidiol (CBD) and tetrahydrocannabinol (THC), which have therapeutic properties. In the development of cannabis-based preparations it is important to have suitable analytical methods for the analysis of the principal cannabinoids. This study aimed to develop and validate a simple and rapid HPLC method with photodiode array detection for determination of CBD and THC in Cannabis sativa oil extract and infused ice cream including a stability study. Chromatographic separation of CBD and THC was performed with a C18 column, with mobile phase consisting of acetonitrile and water with formic acid (80 + 20 v/v) in isocratic elution mode, with detection at 208 nm for CBD and 280 nm for THC and 1.0 mL/min flow rate. The method was linear over a range of 1-5 µg/mL for CBD, and 20-100 µg/mL for THC, the relative standard deviation was <3.6%, the recovery ranged between 98.8-102.5% for oil and 84.0-94.0% for ice cream, QL was 0.33 µg/mL for CBD and 2.30 µg/mL for THC, and the assay demonstrated adequate selectivity. CBD and THC were stable for at least 28 days under light protection at 22 °C, 4 °C and -20 °C in the oil and for at least 60 days at -20 °C in the ice cream. The results showed that the method was suitable for quantitative determination of CBD and THC in Cannabis sativa oil extract and infused ice cream and is useful for quality control purposes. The method is simple and fast and is useful for the quality control of a new product corresponding to an ice cream based on a Cannabis sativa oil extract.

The LactoSens®R method was previously shown to have acceptable accuracy and repeatability precision as required by AOAC Standard Method Performance Requirements (SMPR®) 2018.009 for determination of lactose in low-lactose or lactose-free milk, milk products, and products containing dairy ingredients and was awarded Official Method of AnalysisSM (OMA) First Action status in 2020. The method was subjected to a multilaboratory validation (MLV) study to evaluate the reproducibility precision of the method. Fourteen validation materials were provided to 15 laboratories in 7 countries as blind duplicates. The materials ranged from 0 to 173 mg/100g lactose. Each laboratory analyzed the blind duplicates according to OMA 2020.01. The data were analyzed for repeatability and reproducibility precision. RSDr values varied from 2.81 to 8.76% and RSDR values varied from 4.25 to 12.5%. When sorted by category and concentration range, these results met the repeatability and reproducibility criteria required by SMPR 2018.009. The data generated in the MLV support the adoption of OMA 2020.01 as Final Action status. The LactoSensR method, as described by OMA 2020.01, provides an accurate and precise determination of lactose in a variety of low-lactose and lactose-free milk, milk products, and products containing dairy ingredients in minutes.

Maple syrup is a sought-after commodity and an active target of economically motivated adulteration (EMA), similar to other foods such as lemon juice and honey. It is used as a condiment and a sweetener. This study is aimed to detect adulteration in maple syrup via an internal standard method using malic acid through solid phase extraction (SPE) and liquid chromatography with isotope ratio mass spectrometric detection (LC-IRMS). In this work, an optimized SPE sample preparation procedure was used for the isolation of organic acids from maple syrup. Using LC-IRMS, malic acid was separated from other organic acids and the δ13C value of malic acid was determined. Eleven maple syrup samples, domestic or imported from Canada, were evaluated for 13C/12C ratios (δ13C values) using combustion module-cavity ring down spectrometry (CM-CRDS) and compared to the δ13C values obtained from well-established elemental analyzer-isotope ratio mass spectrometry (EA-IRMS) methods. The δ13C values of isolated malic acid analyzed by SPE-LC-IRMS were used as an internal standard and compared to the δ13C values of bulk maple syrup; differences (δ13Csugars - δ13Cmalic acid) values greater than 3.6‰ are indicative of low-cost sugar adulteration. Overall, the results obtained from SPE-LC-IRMS provided a faster, novel analysis approach for determining low-cost sugar adulteration in maple syrup for regulatory purposes. It also provided lower detectable limits of adulteration versus current literature reports using bulk analysis and comparable detection limits to Tremblay and co-workers who utilized an internal standard method. SPE-LC-IRMS is a robust method that can be used for detecting adulteration in maple syrup samples for regulatory purposes. Faster, novel analysis approach for determining C4 adulteration in maple syrup with lower detection limits.

An LC-MS/MS method was developed for determination and confirmation of tilmicosin in bovine, swine, chicken, and Turkey tissues (liver, kidney, muscle, and skin/fat) and bovine milk. The method was subjected to single laboratory validation to establish method performance parameters. Animal tissues and bovine milk were fortified at 4 concentrations ranging from 0.5 times the lowest maximum residue limit (MRL) or tolerance to 2 times the highest MRL or tolerance considering the Codex and EU MRLs and the US tolerances in the various tissues and milk studied. Incurred tissues were analyzed to verify the precision of the method. The data demonstrated linearity of matrix-matched calibration curves using a weighted (1/x) regression. Recoveries varied from 83.3% to 107.1%. Repeatability precision (RSDr) ranged from 0.465% to 13.4% and intermediate precision (RSDi) ranged from 2.24% to 14.7% in fortified tissue. Repeatability of the method was verified in incurred tissues, ranging from 3.41% to 16.0%. The limits of detection and quantitation of the method are presented and vary by matrix. One confirmatory transition ion was examined across all matrixes and met US and EU criteria for mass spectrometry confirmation. The method was shown to be robust when small changes in method parameters were made and stability of the analyte in fortified tissues, extracts, standard solutions, and matrix matched standards were estimated. The data satisfy the requirements of the AOAC Stakeholder Panel for Veterinary Drug Residue Methods for single laboratory validation studies and the U.S. Food and Drug Administration Center for Veterinary Medicine Guidance for Industry #208 (VICH GL49). The LC-MS/MS method was demonstrated to be suitable for determination and confirmation of tilmicosin residues in in bovine, swine, chicken, and Turkey tissues and bovine milk based on Codex and EU MRLs and US tolerances.

In recent years, due to the global shortage of helium gas, the development of gas chromatography analytical methods using alternative to helium carrier gases is necessary. The objective of this study was to examine the applicability of hydrogen and nitrogen as alternative carrier gases using the test method for azo compounds in the Act on Control of Household Products Containing Harmful Substances of Japan. The gas chromatograph mass spectrometer (GC-MS) analytical method using hydrogen and nitrogen as alternative carrier gases was compared with a method using helium for 26 primary aromatic amines originated from azo dyes. When hydrogen and nitrogen were used as carrier gases under the same conditions used during analysis using helium (same column, gas flow rate, oven temperature conditions, etc.), sufficient peak separation of 26 primary aromatic amines was obtained. The sensitivities of the methods using helium and hydrogen were comparable, whereas the sensitivity was lower when nitrogen was used, with the detection limits ranging from 1/220 to 1/25. However, all carrier gases achieved quantification at concentrations below the standard value (30 μg/g) of the Act on Control of Household Products Containing Harmful Substances, and the results were in agreement with the standard value for the target product. Our results indicated that hydrogen or nitrogen can be used as alternative carrier gases to helium for GC-MS analysis of azo compounds producing specific aromatic amines. Using hydrogen or nitrogen as an alternative carrier gas to helium, azo compounds could be quantified with excellent accuracy.

Sulfite is the oldest and most widely used additive in our food supply with antioxidant and preservative properties. Due to its allergenic-like reactions and other adverse health effects, it`s use is regulated by international regulatory bodies. Therefore, food industries as well as regulatory laboratories must ensure that the maximum concentration of sulfite permitted is not exceeded. The AOAC approved official method for the quantification of sulfites is the Optimized Monier-Williams Method (AOAC Official Method 990.28), which consists of a time consuming titration. The present study aims to demonstrate the reliability of the BIOFISH 300 SUL, a simple, fast, and accurate method, as an alternative, for the quantification of total sulfites in shrimp, with a lower limit of quantification than that of the OMA 990.28, which is 10 ppm. The BIOFISH 300 SUL method is a highly specific biosensor based on its proprietary enzyme-based electrode, for the rapid quantification of total sulfite. The test kit consists of an electrochemical reader (biosensor BIOFISH 300) and disposable electrodes (Biotest) that are capable of providing an electrical signal proportional to the amount of sulfite in the sample analyzed. The method mainly consists of the extraction of sulfite from the solid matrix in an aqueous solution, and its subsequent quantification by the device in less than 3 min. Comparative studies between BIOFISH 300 SUL and OMA 990.28 were conducted for naturally contaminated and spiked samples of raw and boiled shrimp with sulfite levels covering 7-150 mg/kg range in order to determine linearity, recovery, repeatability, intermediate reproducibility, and accuracy. The BIOFISH 300 SUL method demonstrated high accuracy and precision for the whole range of quantification (7-150 mg/kg). Its ease of use and fast response make it the ideal technology to be implemented by the industry. It was adopted as First Action Official MethodSM by the AOAC Expert Review Panel for Sulfites in Seafood Methods in February 2021 after rigorous review.

The estimation of drugs (contain Drospirenone (DRSP) and Ethinyl Estradiol (EE)) and their related impurities in low-dose oral contraceptive drug products is an extremely challenging target. The proposed research sought to develop and validate a stability-indicating method for quantifying drug substances and its related impurities in tablet formulation. To develop and validate a simple, specific, accurate, precise, and stability-indicating RP-HPLC method for quantification of DRSP, EE, and their impurities in accordance with ICH guidelines. The separation was achieved using the Agilent Zorbax SB C18 column (4.6 mm × 250 mm, 5 µm) with a detection wavelength of 215 nm and mobile phases A (100% Acetonitrile) and B (Acetonitrile: Water 1:3 v/v) at a flow rate of 1.3 mL/min and a column temperature of 40 °C. The recovery study of each impurity was conducted in the range of 24 µg/mL to 72 µg/mL for DRSP-related impurities and 0.2 µg/mL to 0.6 µg/mL for EE-related impurities with respect to the specification limit. A linearity study was conducted in a range of 1.5 µg/mL to 90 µg/mL for DRSP and DRSP-related impurities, 0.125 µg/mL to 0.75 µg/mL for EE-related impurities. The QbD study demonstrates the method's robustness. As per current guidelines, a stability-indicating method has been developed for the determination of impurities in DRSP/EE film-coated tablets. A QbD-based robustness test was performed and the method was found to be robust. A gradient, accurate, precise, and stability-indicating reverse phase HPLC method has been developed and validated to determine drospirenone, ethinyl estradiol, and its nine related impurities in tablet formulation. A Quality by Design technique is used to establish a robustness study.