Diaryl pyrrolone fluorescent probing strategy for Mirabegron determination through condensation with ninhydrin and phenylacetaldehyde: Application to dosage forms, human urine and plasma

Mirabegron (MRB) is a β3-adrenoceptor agonist used for managing overactive bladder syndrome. A cost-effective, environmentally friendly, and highly sensitive spectrofluorimetric method was suggested to serve the purpose of quantifying MRB in its pure state, pharmaceutical tablets, spiked human plasma and urine, and testing content uniformity. In the present study, ninhydrin and phenylacetaldehyde react with the amino group moiety of MRB in Teorell-Stenhagen buffer (pH 7.5) to generate a strongly fluorescent diaryl pyrrolone compound that emits fluorescence at a wavelength of 477 nm upon excitation at 385 nm. The obtained calibration curve showed a linear relationship with a high correlation coefficient (r = 0.9997) in the concentration range of 0.25 to 5.0 µg mL-1. Limits of detection (LOD) and quantitation (LOQ) were 0.082 and 0.248 µg mL-1 respectively. The procedure was verified in accordance with the ICH guidelines. The suggested approach could be utilized for the selective analysis of MRB in its pharmaceuticals, either containing a single drug or co-formulated with solifenacin succinate. The greenness of the suggested method was confirmed using different green analytical metrics.

Turn-on fluorescence of mirabegron for its sensitive detection in human plasma: Box-Behnken-Design for optimization

Here, a novel fluorescence strategy was established for the detection of mirabegron (MBG) sensitively on the basis of hantzsch dihydropyridine synthesis. The developed method adopts turn-on fluorescence of MBG for the first time, permitting its selective determination in spiked human plasma at 486 nm after excitation at 410 nm. The developed method exhibited a good linear range from 0.5 μgmL-1 to 2.0 μgmL-1 with detection and quantification limits of 0.05 and 0.2 (μgmL-1), respectively. The profitable applicability of the developed method in spiked human plasma samples was demonstrated, achieving limit of detection below the previously levels reported by spectroscopic methods, allowing application of the developed method for selective determination of MBG in its tablets and spiked human plasma samples with good recovery.

Development of Green HPTLC method for simultaneous determination of a promising combination Tamsulosin and Mirabegron: stability-indicating assay was examined

Recently, mirabegron has been added to tamsulosin to treat overactive bladder in men with benign prostatic hypertrophy. A Rapid, selective, sensitive, and green high-performance thin-layer chromatography (HPTLC) approach was developed for the simultaneous determination of tamsulosin (TAM) and mirabegron (MIR) in pure and laboratory-prepared mixture. Complete separation was obtained on silica gel F254 using the solvent system methanol-ethyl acetate-ammonia (3:7:0.1, v/v). Short-wave ultraviolet light at 270 nm was used to view the chromatographic bands. For MIR and TAM, the suggested technique revealed compact spots with retention factor Rf values of 0.42 and 0.63, respectively. Within concentration ranges of 0.15-7.5 µg/band and 0.05-2.5 µg/band, good linearity was observed, with mean percentage recoveries of 100.04 ± 0.56 and 99.98% ± 0.95 for MIR and TAM, respectively. Green assessment of the developed HPTLC technique was estimated using different green analytical chemistry metrics such as Analytical eco-scale Analytical GREEness (AGREE), and Green Analytical Procedure Index (GAPI) metrics. The proposed method was effectively used as a stability-indicating assay to assess the presence of MIR and TAM in the pharmaceutical dosage form in the presence of their degradation product. The statistical analysis showed high precision and accuracy.

Comprehensive stability-indicating method development of Avanafil Phosphodiesterase type 5 inhibitor using advanced Quality-by-Design approach

Avanafil (AV) is the phosphodiesterase (PDE) type 5 inhibitor drug used in erectile dysfunction, having pyrrolidine, pyrimidine, carboxamide, and chlorine as functional groups which can easily break by environmental changes and cause toxicity. Henceforth, in detail, HPLC stability study with the Quality-by-Design (QbD) approach is presented which leads to recommended storage conditions. The stability of AV was analyzed in hydrolysis, photolysis, and thermal and oxidative conditions. The application of the QbD approach during the stability method development comprises steps as screening and optimization. Quality target product profile (QTPP) was defined, and critical quality attributes (CQAs) were assigned to meet the QTPP requirements. Primary parameters obtained from the Ishikawa diagram were studied via Placket–Burman, and four critical factors were optimized through the central composite design (CCD). The finalized method includes mobile phase [10 mM ammonium acetate, pH 4.5 adjusted by acetic acid:ACN (60:40, v/v)] at 0.9-mL/min flow rate and 239-nm wavelength. A control strategy was set up to ensure that the method repeatedly meets the acceptance criteria. Overall, 16 degradation product peaks of AV in all conditions (solid and solution state) were identified with optimized method and evaluated by HPLC-PDA study. A comprehensive systemic optimization of AV stability study is stated for the first time, which reveals that AV is prone to degrade in sunlight, moisture, and temperature. Global regulators and manufacturers should take care of the packaging, handling, and labeling of AV. A fully validated LC–MS compatible stability method can be successfully applied to monitor AV stability from its formulation which can be wisely extrapolated to assess the AV from biological samples.

Design and virtual screening of novel fluoroquinolone analogs as effective mutant DNA GyrA inhibitors against urinary tract infection-causing fluoroquinolone resistant Escherichia coli

Fluoroquinolones (FQs) belong to the class of quinolone drugs that are used to treat Urinary tract infections (UTIs) through inhibition of E. coli DNA gyrase. Resistance to FQs poses a serious problem in the treatment against resistant strains of E. coli which are associated with Ser83 to Leu and Asp87 to Asn mutations at the quinolone resistance determining region (QRDR) of the GyrA subunit of DNA gyrase. Mutant DNA GyrA (mtDNA GyrA) is deemed to be a significant target for the development of novel FQ drugs. Due to resistance to FQ drugs, discovery or development of novel FQs is crucial to inhibit the mtDNA GyrA. Hence, the present study attempts to design and develop novel FQs that are efficient against resistant E. coli strains. A three-dimensional structure of the mtDNA GyrA protein was developed by homology modeling, following which 204 novel FQ analogs were designed using target based SAR. The designed ligands were then screened using molecular docking studies, through which the pattern of interaction between the ligands and the target protein was studied. As expected, the results of the docking study revealed that the molecules FQ-147, FQ-151 and FQ-37 formed hydrogen bonding and Van der Waals interactions with Leu83 and Asn87 (mutated residues), respectively. Further, the wild-type (WT), mtDNA GyrA and docking complex were studied by molecular dynamics (MD) simulations. Subsequently, all the screened compounds were subjected to a structure and ligand based pharmacophore study followed by ADMET and toxicity (TOPKAT) prediction. Finally, eighteen hit FQ analogs which showed good results for the following properties, viz., best binding score, estimated activity (MIC value) and calculated drug-like properties, and least toxicity, were shortlisted and identified as potential leads to treat UTI caused by FQ resistant E. coli. Apart from development of novel drug candidates for inhibition of mtDNA GyrA, the present study also contributes towards a superior comprehension of the interaction pattern of ligands in the target protein. To a more extensive degree, the present work will be useful for the rational design of novel and potent drugs for UTIs.

Design and development of novel fluoroquinolones analogs using target (mutant DNA GyrA), ligand-based SAR and virtual screening techniques.

Development of a stability-indicating UPLC method for terconazole and characterization of the acidic and oxidative degradation products by UPLC-Q-TOF/MS/MS and NMR

Terconazole, a triazole antifungal drug, is used to treat infections in the form of a cream or suppositories.

Identification of stress degradation products of iloperidone using liquid chromatography coupled with an Orbitrap mass spectrometer

RATIONALE

Iloperidone (ILOP) is an atypical antipsychotic drug used for the treatment of schizophrenia and related psychotic disorders. Comprehensive stress testing of the ILOP drug was carried out as per ICH guidelines to understand its degradation profile. The presence of degradation products in a drug affects not only the quality, but also the safety and efficacy of drug formulation. Thus, it is essential to develop an efficient analytical method which can be useful for the separation, identification and characterization of all possible degradation products of ILOP.

METHODS

ILOP was subjected to various stress conditions such as acidic, basic, neutral hydrolysis, oxidation, photolysis and thermal conditions; and the resulting degradation products were investigated using LC-PDA-HRMS and MS/MS. An efficient and simple ultra-high-performance liquid chromatography (UHPLC) method has been developed on Acquity UPLC® BEH C18 column (2.1 × 100mm, 1.7 μm) using a gradient elution of heptafluorobutyric acid (0.1% HFBA) and acetonitrile as mobile phase.

RESULTS

ILOP was found to degrade under acidic and basic hydrolysis and oxidative stress conditions, whereas it was stable under neutral hydrolysis, thermal and photolytic conditions. A total of seven degradation products (DP1 to DP7) were identified and characterized by LC/MS/MS in positive ion mode with accurate mass measurements. The hydrolytic degradation under acidic and basic conditions produced two DPs (DP1 and DP2) and four DPs (DP4 to DP7), respectively, whereas DP3 was formed under oxidative conditions. In silico toxicity predictions showed higher probability values for DP4, DP6 and DP7, which indicates these DPs have the potential to mutate DNA.

CONCLUSIONS

ILOP was found to be labile under hydrolytic and oxidative conditions. The structures of the degradation products were rationalized by appropriate mechanisms. The proposed method can be effectively used for the determination and detection of ILOP and its degradation products.

Principle, Instrumentation, and Applications of UPLC: A Novel Technique of Liquid Chromatography

The key focus of the pharmaceutical or chemical industries is to reduce the cost involved in the development of new drugs and to improve the selectivity, sensitivity, and resolution for their detection. The purpose can now be solved by the separation method called UPLC which is the modified HPLC method comprising high pressure and small sized particles (less than 2 µm) used in the column, so the length of the column decreases leading to time saving and reduction in the consumption of solvent. The underlying principle of UPLC is based on van Deemter statement which describes the connection between linear velocity with plate height. UPLC contributes to the improvement of the three areas: speed, resolution, and sensitivity. This is a new advanced category of the HPLC which has the same basic principle and methodology with improved chromatographic performance. This review is an effort to compile the principle, instrumentation, and applications of UPLC.

Using an innovative quality-by-design approach for the development of a stability-indicating UPLC/Q-TOF-ESI-MS/MS method for stressed degradation products of imatinib mesylate

Chromatography modeling softwares (DryLab®2000 plus and Design Expert®​8.0.6) were used to develop a stability indicating UPLC/Q-TOF-ESI-MS/MS method for the simultaneous determination of stressed degradation products of imatinib mesylate.​

Rapid structural characterization of in vivo and in vitro metabolites of tinoridine using UHPLC-QTOF-MS/MS and in silico toxicological screening of its metabolites

Tinoridine is a nonsteroidal anti-inflammatory drug and also has potent radical scavenger and antiperoxidative activity. However, metabolism of tinoridine has not been thoroughly investigated. To identify in vivo metabolites, the drug was administered to Sprague-Dawley rats (n = 5) at a dose of 20 mg kg(-1), and blood, urine and feces were collected at different time points up to 24 h. In vitro metabolism was delved by incubating the drug with rat liver microsomes and human liver microsomes. The metabolites were enriched by optimized sample preparation involving protein precipitation using acetonitrile, followed by solid-phase extraction. Data processes were carried out using multiple mass defects filters to eliminate false-positive ions. A total of 11 metabolites have been identified in urine samples including hydroxyl, dealkylated, acetylated and glucuronide metabolites; among them, some were also observed in plasma and feces samples. Only two major metabolites were formed using liver microsomal incubations. These metabolites were also observed in vivo. All the 11 metabolites, which are hitherto unknown and novel, were characterized by using ultrahigh-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry in combination with accurate mass measurements. Finally, in silico toxicological screening of all metabolites was evaluated, and two metabolites were proposed to show a certain degree of lung or liver toxicity.