Simultaneous determination of bambuterol and its two major metabolites in human plasma by hydrophilic interaction ultra-performance liquid chromatography–tandem mass spectrometry

Stability indicating eco-friendly quantitation of terbutaline and its pro-drug bambuterol using quantitative proton nuclear magnetic spectroscopy

Quantitative 1H-NMR became an increasingly important issue in pharmaceutical analytical chemistry. This study used NMR spectroscopy to assay the bronchodilator drug terbutaline sulfate and its pro-drug bambuterol hydrochloride in pure form and pharmaceutical preparations. The technique proceeded using deuterium oxide (D2O) as an 1H-NMR solvent and phloroglucinol anhydrous as an internal standard (IS). Comparatively, to the phloroglucinol signal at 5.9 ppm, the resulting quantitative signals of the studied drugs were corrected. The terbutaline singlet signal at 6.3 ppm was chosen for quantification, while the bambuterol quantitative singlet signal was at 2.9 ppm. The two drugs were rectilinear over the concentration range of 1.0-16.0 mg/mL. LOD values were 0.19 and 0.21 mg/mL while LOQ values were 0.58 and 0.64 mg/mL for terbutaline and bambuterol respectively. The developed method has been validated according to the International Conference of Harmonization (ICH) regarding linearity, accuracy, precision, specificity, and robustness. A greenness profile assessment was applied, and the method proved to be green. The method enables the assay of the two drugs in pure drug and pharmaceutical preparations. The method also enables the assay of the two drugs in the presence of each other; thus, it is considered a stability-indicating method where terbutaline is an acid degradation product of bambuterol.

Micelle-enhanced spectrofluorimetric method for the rapid determination of bronchodilator terbutaline and its prodrug bambuterol: Application for content uniformity test

A novel, simple and sensitive spectrofluorimetric approach for determination of terbutaline sulphate (TER) and its prodrug bambuterol (BAM) in their pure and pharmaceutical dosage forms was developed. The suggested approach depends on enhancing the native fluorescence of either TER or BAM at 315 and 297.2 nm after excitation at 277 and 259 nm, respectively, using sodium dodecyl sulphate (SDS) as a micellar media. In the presence of 0.7% w/v SDS, about 1.38-fold and 1.18-fold enhancement is achieved in the relative fluorescence intensity (RFI) of TER and BAM, respectively. The fluorescence-concentration curves were rectilinear over the concentration range of 0.8-16 μg mL^-1 , with detection limits (LOD) of 0.252 and 0.26 (μg mL-1), quantitation limits (LOQ) of 0.76 and 0.79 (μg mL-1), determination coefficients (r2) of 0.9981, and slopes of 45.92 and 10.44 for TER and BAM, respectively. The suggested approach was validated in accordance with ICH criteria and was effectively applied in the analysis of the studied drugs in their commercial tablets. The high sensitivity of the proposed approach allows its application in evaluating the content uniformity testing of the studied drugs in their tablets through using the official United States Pharmacopeia criteria (USP). Statistical analogies of the findings with that of the reported methods showed really good harmony and indicated no major differences in precision and accuracy.

Hydrophilic Interaction Liquid Chromatography (HILIC): Latest Applications in the Pharmaceutical Researches

Background:

Significant advances have been occurred in analytical research since the 1970s by Liquid Chromatography (LC) as the separation method. Reverse Phase Liquid Chromatography (RPLC) method, using hydrophobic stationary phases and polar mobile phases, is the most commonly used chromatographic method. However, it is difficult to analyze some polar compounds with this method. Another separation method is the Normal Phase Liquid Chromatography (NPLC), which involves polar stationary phases with organic eluents. NPLC presents low-efficiency separations and asymmetric chromatographic peak shapes when analyzing polar compounds. Hydrophilic Interaction Liquid Chromatography (HILIC) is an interesting and promising alternative method for the analysis of polar compounds. HILIC is defined as a separation method that combines stationary phases used in the NPLC method and mobile phases used in the RPLC method. HILIC can be successfully applied to all types of liquid chromatographic separations such as pharmaceutical compounds, small molecules, metabolites, drugs of abuse, carbohydrates, toxins, oligosaccharides, peptides, amino acids and proteins.

Objective:

This paper provides a general overview of the recent application of HILIC in the pharmaceutical research in the different sample matrices such as pharmaceutical dosage form, plasma, serum, environmental samples, animal origin samples, plant origin samples, etc. Also, this review focuses on the most recent and selected papers in the drug research from 2009 to the submission date in 2020, dealing with the analysis of different components using HILIC.

Results and Conclusion:

The literature survey showed that HILIC applications are increasing every year in pharmaceutical research. It was found that HILIC allows simultaneous analysis of many compounds using different detectors.

Differential effects of inhaled R- and S-terbutaline in ovalbumin-induced asthmatic mice

Inhaled terbutaline is commercially available β₂-agonist which consists of equivalent amount of R- and S-enantiomer. In this study, we aimed to investigate the effects of single enantiomers of terbutaline and its racemate in an ovalbumin (OVA)-induced mouse model of asthma via. seven days inhalation and the potential mechanisms involved. In a standard experimental asthma model, BALB/c mice were sensitized and challenged with OVA. R-terbutaline (R-ter), S-terbutaline (S-ter) or racemic terbutaline (rac-ter) was given via. nose-only inhalation for one week. Airway responsiveness to methacholine was measured by the plethysmography in conscious mice. Eosinophils counts in blood and bronchoalveolar (BAL) fluid were determined. The OVA-sIgE in plasma and inflammatory cytokines and mediators in BAL fluid or lung tissue were analyzed by ELISA, qRT-PCR or western blotting. Airway inflammation and remodeling were evaluated with hematoxylin and eosin (HE), periodic acid-Schiff (PAS), and Masson staining. Drug distribution and deposition after inhalation were determined by LC-MS/MS. Our data showed that R-ter efficiently ameliorated asthma responses, including airway hyperresponsiveness, eosinophils influx and IL-5 in BALF, plasma OVA-sIgE and significantly reduced pulmonary inflammation, peribronchial smooth muscle layer thickness, goblet cell hyperplasia, and deposition of collagen fibers, as well as downregulation of p38 MAPK phosphorylation and NF-κB expression. Racemic mixture exhibited diminished effects while S-ter enhanced airway responsiveness to methacholine and exerted pro-asthmatic effects.

In vivo metabolism study of (R)-bambuterol in humans using ultra high performance liquid chromatography with tandem mass spectrometry

(R)-Bambuterol, a selective β2-adrenoceptor agonist, has been approved as a new drug for the treatment of asthma and chronic obstructive pulmonary disease by the China Food and Drug Administration and is currently under phase I clinical trials. In this study, a combined method based on ultra high performance liquid chromatography with triple quadrupole mass spectrometry and ultra high performance liquid chromatography with quadrupole time-of-flight mass spectrometry was employed for the identification of the major metabolites of (R)-bambuterol in human plasma and urine after an oral dose of 10 mg. The metabolites were separated by gradient elution program and different sample preparation methods were compared. Totally, 12 metabolites of (R)-bambuterol were identified, including four metabolites in plasma and all 12 metabolites in urine. Among these, four metabolites are reported for the first time. The possible metabolic pathways of (R)-bambuterol were subsequently proposed. The results indicated that (R)-bambuterol was metabolized via hydrolysis, demethylation, oxygenation, glucuronidation, and sulfation pathways in vivo. This study revealed that this combined method was accurate and sensitive to identify the possible metabolites and to better understand the metabolism of (R)-bambuterol in vivo.