A nonsteroidal drug called flurbiprofen (FBN) has analgesic, anti-inflammatory and antipyretic activity. Currently the determination of FBN in cataplasm does not have any pharmacopeial method. However, the drug substance, tablet and ophthalmic solution formulations do have pharmacopeial methods. The development and validation of an accurate, precise and stability-indicating analytical method for the determination of FBN in cataplasm formulations is reported. The gradient method was employed for the quantification of FBN in the presence of internal standards such as biphenyl. A nonpolar separation phase (C18 , 250 × 4.6 mm, 5 μm Inertsil column; GL Sciences) was used. The optimal flow rate, column oven temperature, injection volume and detector wavelengths were 1.0 ml/min, 40°C, 20 μl and 245 nm, respectively. Mobile phase A was a mixture of water and glacial acetic acid (30:1 v/v) pH adjusted to 2.20 with glacial acetic acid or 1m NaOH; mobile phase B was methanol (100%). The gradient elution program was [time (min)/% B]: 5/60, 20/70, 25/70, 30/60 and 40/60. The obtained RSDs for the precision and intermediate precision were 0.7 and 0.5%. The percentage recovery ranged from 99.2 to 100.4%. The linear regression coefficient >0.9996 indicates that all peak responses were linear with the concentration. The sample and standard solutions were stable for up to 24 h on the benchtop and in the refrigerator. The critical peaks were well separated from the generated peaks owing to forced degradation, including diluent and placebo peaks. The method validation data and quality by design-based robustness study results indicate that the developed method is robust and fit for routine use in the quality control laboratory. The proposed method is specific, accurate and precise, and the quality by design utilized the first method for the determination of FBN in cataplasm formulations. Transdermal patches and gels have low extraction capacity and this method is applicable for quantification.

Valproic acid (VPA) is a classic medication for several types of epilepsy and mood disorders, and some of its effectiveness and toxicity is associated with metabolites. Although many reports have reported the drug-drug interactions of VPA, no study has focused on the influence of carbapenems (CBPMs) on VPA's active metabolites. An LC-MS/MS method for determining VPA and its six metabolites (3-hydroxy valproic acid, 4-hydroxy valproic acid, 2-propyl-2-pentenoic acid, 2-propyl-4-pentenoic acid, 3-keto valproic acid, and 2-propylglutaric acid) in human serum was established and applied to evaluate the drug-drug interaction with CBPMs in epileptic patients. The stable isotope valproic acid-d6 was used as an internal standard. Analytes in serum samples (50 μl) were isolated using a Kinetex C18 column (3× 100 mm, 2.6μm) and detected via negative electrospray ionization after protein precipitation. It was linear (r> 0.99) over the calibration range for different analytes. The accuracy was 91.44-110.92%, and the precision was less than 9.98%. The matrix effect, recovery, and stability met the acceptance criteria. According to the data collected from 150 epileptic patients, the concentration-dose ratio for VPA and its metabolites decreased with CBPM polytherapy. This method is simple and rapid with great accuracy and precision. It is suitable for routine clinical analysis of VPA and its metabolites in human serum.

A novel LC-MS method was developed and validated to determine three potential genotoxic impurities, namely 2-(2-aminophenylthio)benzoic acid hydrochloride, 2-aminothiophenol, and 2-(2-aminophenylthio)benzonitrile, at trace level (~1.6ppm) in quetiapine fumarate drug substance, an antipsychotic drug. These impurities are potentially genotoxic and therefore should be controlled at or below specific acceptance limits. An InertSustain AQ-C18 column (250 × 4.6 mm, 5 μm) in reversed-phase mode with the column temperature at 45°C was used. The mobile phase was 0.1% trifluoroacetic acid in water and acetonitrile with gradient elution mode, and the run time was 45 min. The flow rate was 0.8 ml/min. A mass spectrometer was used to quantify the amount of impurities using electrospray ionization mode at specific m/z 245.9, 126.0, and 226.9 for 2-(2-aminophenylthio)benzoic acid hydrochloride, 2-aminothiophenol, and 2-(2-aminophenylthio) benzonitrile, respectively. The method was found to be sensitive and possessed excellent linearity in the concentration ranges from the limit of quantification to 150% of the permitted level (0.47-2.36 μg/ml) with correlation coefficients above 0.999. The results showed that the method was specific, precise, linear, and accurate for the estimation of these three impurities in quetiapine fumarate.

The purpose of this review study was to sum up the main recent advances reported in the scientific literature about the detection of common drugs of abuse in biological samples upon their collection by dried blood spot devices. The most recent, innovative and fully validated methods for the qualitative and/or quantitative detection of common drugs of abuse are reported, including alprazolam, clonazepam, diazepam, 3,4-methylenedioxymethamphetamine, 3,4-methylenedioxyamphetamine, 3,4-methyl-enedioxyethylamphetamine, amphetamine, methamphetamine, cocaine, tetrahydrocannabinol, 6-monoacetylmorphine, morphine, codeine, hydromorphone, hydrocodone, oxycodone, noroxycodone, tramadol, methadone, buprenorphine, fentanyl, ketamine and their respective metabolites and γ-hydroxybutyric acid. Dried blood spot proved to be extremely promising for routine analysis of forensic cases, although large-scale experiments on real samples need to be performed to confirm the emerging advantages of the technique and remove the potential limitations still affecting its widespread application.

The present study describes forced degradation of benidipine (BEN) as per Q1A (R2) and Q1B guidelines of the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use. BEN degraded under hydrolysis (neutral, acidic, and alkaline), hydrogen peroxide induced oxidation, and UV light mediated photolytic degradation. A total of 14 degradation products (DPs) were found in all degradation studies, comprising 4 hydrolytic DPs, 8 oxidative DPs, and 4 photolytic DPs. A selective stability-indicating method was developed using an XBridge BEH C18 column with gradient elution program consisting of ammonium acetate (10mM, 4.8 pH, acetic acid) and acetonitrile. The flow rate was maintained at 1ml min-1 . All DPs were separated well using the developed HPLC method and were characterized using LC-MS/MS data. As this method is effective in identifying and separating BEN and its DPs with sufficient resolution, it can be used in laboratories for quality control of drugs in daily routine analysis and stability studies.

Preterm birth and enteral feeding are two main factors leading to necrotizing enterocolitis (NEC). The metabolomics of preterm infants before and after feeding can provide a basis for the prediction of NEC. Using the method of cross‐sectional study, the mode was established with the serum samples of 19 premature infants at birth and after feeding as the control group. The serum was analyzed using GC–MS. Chemometric analysis includes principal component analysis, partial least squares‐discriminant analysis, and orthogonal partial least squares‐discriminant analysis. Spectral separation of serum metabolites occurred in premature infants before and after feeding. The levels of xylose, d‐talose, phosphoglycolic acid, maleimide, l‐gulonolactone, maleic acid, β‐hydroxypyruvate, itaconic acid, and pantothenic acid in the serum of premature infants after feeding were significant in both multidimensional and single‐dimensional modes (variable importance in projection >2, P < 0.01). There was a moderate correlation between total bilirubin and l‐gulonolactone and β‐hydroxypyruvate (0.8 > r > 0.5). Maleimide, maleic acid, and itaconic acid have diagnostic value (area under the curve >0.9). The results indicated that serum metabolism of preterm infants changes significantly after feeding. Some metabolites have potential value in predicting NEC.

Exercise training is the cornerstone component of pulmonary rehabilitation, which results in symptom-reducing, psychosocial, and health economic benefits for chronic obstructive pulmonary disease (COPD) patients. However, the potential mechanisms of its action are poorly understood. This study conducted serum metabolomics using ultra-high performance liquid chromatography-Q-Exactive tandem mass spectrometry to determine the metabolic changes in COPD rats, and the effects of exercise training on improvement in COPD were further investigated. Twelve differential metabolites-which are primarily related to tryptophan metabolism, sphingolipid metabolism, glycerophospholipid metabolism, riboflavin metabolism, pantothenate and CoA biosynthesis, and lysine degradation-were identified in relation to COPD. After the intervention of exercise training, the levels of most metabolites were restored, and the changes in five metabolites were statistically significant, which suggested that exercise training provided effective protection against COPD and might play its role by rebalancing disordered metabolism pathways. This work enhanced our comprehension of the protective mechanism of exercise training on COPD.

Midostaurin (MTN), designated as an orphan medicinal product, is emerging as an important drug for treating acute myeloid leukemia and advanced systematic mastocytosis. The proposed method was developed and validated to evaluate the related impurities of MTN. The impurities were separated using a YMC Trait C18 ExRS column (150 × 4.6mm, 3μm). Mobile phase A consisted of a 10-mM concentration of phosphate buffer adjusted to pH3.0 with diluted orthophosphoric acid, and mobile phase B consisted of 90% acetonitrile and 10% water. The optimized chromatographic conditions were as follows: flow rate, 0.5mL min-1 ; injection volume, 10μL; UV detection, 290 nm; and linear gradient program, up to 65 min. The method was developed using an analytical quality by design approach. A systematic flow chart shows the evaluation, control, and life cycle management method. As part of method evaluation, risk assessment was conducted. The method has been validated per current guidelines of the International Conference on Harmonization. The recovery study and linearity ranges were established from the limit of quantification to 150% optimal concentrations. The recovery was found to be between 95.5 and 102.5%, and linearity (r2 ) was 0.9998-0.9999 for all the identified impurities. The method precision results were achieved below 10% of relative standard deviation. Forced degradation studies were performed under chemical and physical stress conditions. The compound was sensitive to chemical stress conditions. During the study, the analyte degraded and was converted into the identified degradation impurities, and its molecular mass was found using the LC-MS technique.

Huangqi Jianzhong Tang (HQJZ) is a famous traditional Chinese medicine formula widely used in the treatment of gastrointestinal diseases in China. In this study, an ultra-performance liquid chromatography-mass spectrometry (UHPLC-MS/MS) was used to study the pharmacokinetics of 12 prototypical components and one metabolite in HQJZ in normal and chronic atrophic gastritis rats. The results showed that the area under the concentration-time curve and peak concentration of most flavonoids and flavonoid glycosides were decreased, and the half-life and mean residence time were significantly increased, which indicated that the absorption of drugs in disease was decreased less and for longer in vivo. Then, an integrated pharmacokinetic study was carried out using the pharmacokinetic parameter model integration of each component. The results showed that the absorption of drugs in vivo with disease was reduced, and the absorption speed of flavonoids and flavonoid glycosides was accelerated. This study will provide the basis for the clinical medication safety of HQJZ.

The study objective was to analyse the phytochemical constituents in aerial extracts of these plants using an HPTLC method and optimization by quality by design. Qualitative analysis of ephedrine in hydro-alcoholic extract was done via HPTLC, using a mobile phase of toluene-ethyl acetate-chloroform-formic acid in the ratio of 1:0.5:0.5:01 and the peaks were monitored at 366 nm. In the hydro-alcoholic aerial part extract, ephedrine was identified using the HPTLC method and the retardation factor (Rf) value was found to be 0.69 ± 0.01 and 0.69 ± 0.01, as compared with the standard sample. The extraction of plant materials was done using different concentration of water and alcohol solvents and quality by design was applied to optimize the extraction process and to find out the best extraction in an 80:20 ratio of hydro-alcoholic extract. In the hydro-alcoholic extract, the ephedrine was characterized using the HPTLC method and compared with the standard solution, and this method was used in herbal as well as academic research for the identification of ephedrine in poly herbal formulations as well as the ephedrine present in different plant extracts. Response surface methodology software was utilized to predict the path or choose the best extraction method. Sida rhombifolia and Sida cordifolia can be used as substitutes for Ephedra gerardiana based on the HPTLC profile.