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A method of combining magnetic solid-phase separation (MSPE) and chiral capillary electrophoresis (CE) is developed for enantioseparation of trace amounts of β-blockers. Polynorepinephrine-functionalized magnetic nanoparticles (polyNE-MNPs) are synthesized and applied to simultaneously extract three β-blockers (carteolol, metoprolol, and betaxolol). The prepared polyNE-MNPs are spherical with a diameter of 198 ± 17 nm and the thickness of the polyNE coating is about 14 nm. PolyNE possesses abundant catechol hydroxyl and secondary amine groups, endowing the MNPs with excellent hydrophilicity. Under the optimum conditions, the extraction efficiencies of polyNE-MNPs for β-blockers are in the range of 89.6 to 100%, with relative standard deviations (RSDs) below 3.5%. The extraction process can be finished in 4 min. Field-enhanced sample injection (FESI) in chiral CE is constructed to further enhance the sensitivities of β-blocker enantiomers. The limits of detection for β-blocker enantiomers by the FESI-CE with polyNE-MNPs are in the range of 0.401 to 1.59 ng mL -1 . The practicability of this method in real samples is evaluated by analysis of human urine samples. The recoveries for each enantiomer of β-blockers in the real samples range from 89.5 to 92.8%, with RSDs ranging from 0.37 to 5.9%. The whole detection process can be finished in less than 0.5 h. The method demonstrates its great potential in the pharmacokinetic and pharmacodynamic studies of chiral drugs in humans. Graphical abstract ᅟ.

Aim: β-blockers are compounds that bind with adrenoreceptors hindering their interaction with adrenalin and noradrenalin. They are clinically relevant and they are also used in some sport as doping agents., Results: A new method based on the combination of dispersive micro-solid phase extraction and LC-MS/MS has been developed to determine propranolol and carvedilol in urine samples. For this purpose a magnetic-polyamide composite is synthesized and used as sorbent. Working under the optimum conditions, the method provides limits of detection and quantification in the range of 0.1-0.15 μg/l and 0.3-0.5 μg/l, for carvedilol and propranolol, respectively. The precision, expressed as RSD, was better than 9.6% and the relative recoveries varied between 73.7 and 81.3%., Conclusion: The methodology is appropriate for the determination of β-blockers in urine samples at the low microgram per liter range for therapeutic purposes.

HPLC is considered the method of choice for the separation of various classes of drugs. However, some analytes are still challenging as HPLC shows limited resolution capabilities for highly polar analytes as they interact insufficiently on conventional reversed-phase (RP) columns. Especially in combination with mass spectrometric detection, limitations apply for alterations of stationary phases. Some highly polar sympathomimetic drugs and their metabolites showed almost no retention on different RP columns. Their retention remains poor even on phenylhexyl phases that show different selectivity due to π-π interactions. Supercritical fluid chromatography (SFC) as an orthogonal separation technique to HPLC may help to overcome these issues. Selected polar drugs and metabolites were analyzed utilizing SFC separation. All compounds showed sharp peaks and good retention even for the very polar analytes, such as sulfoconjugates. Retention times and elution orders in SFC are different to both RP and HILIC separations as a result of the orthogonality. Short cycle times could be realized. As temperature and pressure strongly influence the polarity of supercritical fluids, precise regulation of temperature and backpressure is required for the stability of the retention times. As CO2 is the main constituent of the mobile phase in SFC, solvent consumption and solvent waste are considerably reduced. Graphical Abstract SFC-MS/MS vs. LC-MS/MS.

Seven solid phase sorbent materials with reversed-phase, mixed-mode interactions (ion-exchange and reversed-phase), and molecularly imprinted polymers (MIP), namely Oasis HLB, Oasis MAX, Oasis MCX, Bond Elute Plexa, Bond Elute Plexa PAX, Bond Elute Plexa PCX, and SupelMIP sorbents, were investigated. The present study was focused on the retention and elution of pharmaceutically active substances based on several analyte-sorbent interaction properties. Basic drugs, such as β-blockers (i.e., atenolol, pindolol, acebutolol, metoprolol, labetalol, and propranolol) were selected as the model compounds for this study. These compounds are frequently encountered in anti-doping tests. The extraction efficiencies of the individual sorbents were compared based on the recovery of known amounts of the targeted analytes in a metered elution volume (500 μL) in three separate elution fractions. The elution efficiency of the total amount of the target analytes on various sorbents was not appreciably influenced by the volume of eluent required for complete elution. Based on the small matrix effects and clear baseline, SupelMIP was the most suitable sorbent for urine analysis. The relative analyte recoveries of the SPE-HPLC procedure proved satisfactory for the range from 94% to 105%, with an RSD ranging from 2% to 4%. The regression equations for all of the targeted compounds exhibited excellent linearity (r(2) > 0.9991) over the range of 10 to 1000 ng mL(-1). The limits of detection and quantification for the selected β-blocker compounds in urine were in the ranges of 0.6 to 2.0 ng mL(-1) and 2.0 to 6.7 ng mL(-1), respectively.

Background: A simple and sensitive CE method was developed and validated for the analysis of some beta blockers in human urine., Methods: In this study, salting-out assisted LLE combined with field-amplified sample stacking method was employed for biological sample clean-up and sensitivity enhancement in CE., Results: Under the optimal conditions good linearity (r(2) ≥0.998) was obtained, within 0.025-1 µg/ml for propranolol and metoprolol, and within 0.05-1 µg/ml for carvedilol in urine samples. LODs and LLOQs ranged from 0.005 to 0.015 µg/ml, and from 0.025 to 0.05 µg/ml, respectively. The RSDs of intra- and inter-day analysis of examined compounds were less than 4.0%. The recoveries were in the range of 98-119%., Conclusion: The validated method is successfully applied to determine propranolol, metoprolol and carvedilol in human urine samples obtained from the patients who received these drugs.

A method has been developed for the determination of 23 beta2-agonists and 5 beta-blockers in urine samples using high performance liquid chromatography-ion trap mass spectrometry (HPLC-IT-MS). Urine samples were first deproteinized by high-speed frozen centrifugation, and the supernatants were loaded on an Extrelut diatomite column for clean-up. The analytes were eluted by ethyl acetate and concentrated for further analysis. The analytical separation was performed on an AtlantisT3-150 mm chromatographic column with the gradient elution using methanol and water (containing 0.1% formic acid). The detection was carried on a linear ion trap mass spectrometer under multiple reaction monitoring (MRM) mode with the source operated in positive mode of electrospray ionization (ESI+). Nine deuterium labeled beta2-agonists were used as internal standards for quantitative analysis. The results showed that the linear ranges for 23 beta2-agonists and 5 beta-blockers were 0.005-0.16 mg/L, and the limits of detection were all around 0.2 microg/L. The mixed standard solution was added into the blank urine samples, and the recoveries of 23 beta2-agonists and 5 beta-blockers were ranged from 57.1% to 127.7% with the relative standard deviations of 1.1%-31.1%. The results demonstrate that the method is easy, fast, sensitive, and suitable for the confirmation and quantification of 23 beta2-agonists and 5 beta-blockers in urine samples.

A method was developed to perform the screening, quantification and confirmation of the five beta-blockers, propranolol, carteolol, bisoprolol, esmolol, and sotalol, in human urine using gas chromatography-mass spectrometry (GC-MS). In sample preparation, conjugated and unconjugated beta-blockers in urine were extracted separately, and the extracts were combined. The extracts were derivatized with N-methyl-N-trimethylsilyl-trifluoroacetamide (MSTFA) and N-methyl-bis(trifluoroacetamide) (MBTFA). The optimal conditions of GC-MS were established, and the progresses of screening by selected ion monitoring (SIM) mode and confirmation by full scan (SCAN) mode were completed. At last, the quantification curves of the five beta-blockers in spiked urine were established by SIM mode. The limits of detection were 0.2 -1.0 ng/mL. Overall recoveries were 70.5% - 103.4%, and the relative standard deviations were lower than 15%. In addition, the method was successfully applied to the analysis of the positive urine of propranolol, and the urinary excretion curve was also established accordingly. It is significant to prohibit the abuse of beta-blockers in doping control.

The hepatic extraction of metoprolol is reduced in rats with bilateral ureter ligation (BUL)-induced renal failure. The aim of the present study was to evaluate the effect of uremic substances on the hepatic metabolism of metoprolol in rats with BUL. The metabolic rate in the liver microsomes of BUL rats was similar to that in sham rats, and there was no significant difference between sham and BUL rats in the effect of the supernatant of liver homogenates on the metabolism. The rate of metabolism in the liver microsomes in the presence of the plasma of BUL rats was also similar to that in the presence of the plasma of sham rats. These findings indicated that uremic substances which accumulate in BUL rats do not directly inhibit the activity of CYP2D2, which is responsible for the metabolism of metoprolol in the rat liver.

Aims: We aimed to investigate effects of grapefruit juice on acebutolol pharmacokinetics., Methods: In a randomized cross-over study, 10 healthy subjects ingested 200 mL grapefruit juice or water three times daily for 3 days and twice on day 4. On day 3, each subject ingested 400 mg acebutolol with grapefruit juice or water. The concentrations of acebutolol and its metabolite diacetolol were measured in plasma and urine up to 33 h., Results: Grapefruit juice decreased the peak plasma concentration (Cmax) of acebutolol by 19% from 872 +/- 207 ng mL(-1) to 706 +/- 140 ng mL(-1) (95% CI on the difference -306, -26.4; P < 0.05), and the area under the concentration time curve (AUC(0-33 h)) by 7%, from 4498 +/- 939 ng mL(-1) h to 4182 +/- 915 ng mL(-1) h (95% CI -609, -23.0; P < 0.05). The half-life (t1/2) of acebutolol prolonged from 4.0 to 5.1 h (P < 0.05). The time to peak concentration and the amount of acebutolol excreted into urine (Ae) were unchanged. The Cmax, AUC(0-33 h), and Ae of diacetolol were decreased by 24% (P < 0.05), 18% (P < 0.05), and 20% (P < 0.01), respectively, by grapefruit juice., Conclusion: Grapefruit juice caused a small decrease in the plasma concentrations of acebutolol and diacetolol by interfering with gastrointestinal absorption. The interaction between the grapefruit juice and acebutolol is unlikely to be of clinical significance in most of the patients.

Over a 10-year period, 1993-2002, Federal Aviation Administration identified 50 pilot fatalities involving atenolol, metoprolol, and propranolol, which is consistent with the fact that these drugs have been in the lists of the top 200 drugs prescribed in the U.S. In a few of the 50 pilot fatality cases, initial analysis suggested the presence of atenolol and metoprolol. However, there was no medical history with these cases supporting the use of both drugs. Therefore, atenolol, metoprolol, and/or propranolol, with their possible metabolite(s), were re-extracted from the selected case specimens, derivatized with pentafluoropropionic anhydride (PFPA), and analyzed by gas chromatography-mass spectrometry (GC-MS). The MS spectra of these three antihypertensives and a metoprolol metabolite are nearly identical. All of the PFPA derivatives had baseline GC separation, with the exception of a metoprolol metabolite product, which co-eluted with atenolol. There were four primary mass fragments (m/z 408, 366, 202, and 176) found with all of the PFPA-beta-blockers and with the interfering metabolite product. However, atenolol has three unique fragments (m/z 244, 172, and 132), metoprolol has two unique fragments (m/z 559 and 107), propranolol has four unique fragments (m/z 551, 183, 144, and 127), and the metoprolol metabolite product has two unique fragments (m/z 557 and 149). These distinctive fragments were further validated by using a computer program that predicts logical mass fragments and performing GC-MS of deuterated PFPA-atenolol and PFPA-propranolol and of the PFPA-alpha-hydroxy metabolite of metoprolol. By using the unique mass fragments, none of the pilot fatality cases were found to contain more than one beta-blocker. Therefore, these mass ions can be used for differentiating and simultaneously analyzing these structurally similar beta-blockers in biological samples.

A sensitive and selective method for the simultaneous determination of carvedilol and ampicillin sodium (AS) in the presence of human serum albumin (HSA) is described. The maximum emission wavelengths of carvedilol and AS are at 357 nm and 426 nm with excitation at 254 nm, respectively. The first-derivative peaks of carvedilol and AS were at 337 nm and 398 nm, respectively. The linear-regression equations of the calibration graphs of carvedilol and AS were C = 0.0001H - 0.0063 and C = 1.530H - 43.84; the correlation coefficients were 0.9990 and 0.9986, respectively. The detection limits were 1 ng ml(-1) for carvedilol and 23 microg ml(-1) for AS, respectively. The effects of the pH, the stability of carvedilol and AS and foreign ions on the determination of carvedilol and AS were examined. The recoveries of carvedilol and AS were measured. This method is simple and can be used for the determination of carvedilol and AS in human serum and urine samples with satisfactory results.

Aim: To study the stereoselectivity of phase II glucuronidation metabolism of side-chain propranolol in Chinese Han population., Methods: Sixteen adult Chinese Han volunteers with an average age of 20 years were given a single oral dose of 20 mg racemic propranolol. Human urine at indicated time after administration was collected and S-(-)-propranolol glucuronide and R-(+)-propranolol glucuronide were determined simultaneously by using RP-HPLC., Results: The mean values of k were 0.19+/-0.04 h(-1) and 0.28+/-0.06 h(-1), of t(1/2) 3.56+/-0.73 h and 2.45+/-0.50 h, of T(max) 2.21+/-0.45 and 1.75+/-0.33 h, and of Xu(0-24) 5.65+/-0.98 and 2.95+/-0.62 micromoL for S-(-)- and R-(+)-propranolol glucuronide, respectively. The cumulative excretion percentages in urine of doses were 14.7+/-2.46% and 7.68+/-1.60% for S-(-)- and R-(+)-propranolol glucuronide, respectively. The results showed the elimination rate constant k of S-(-)-propranolol glucuronide was less than that of R-(+)-propranolol glucuronide; and the elimination half-life (t(1/2)), T(max) and the cumulative excretion amount(Xu(0-24)) of R-(+)-propranolol glucuronide were significantly less than that of S-(-)-propranolol glucuronide., Conclusion: The propranolol glucuronidation of the side-chain undergoes stereoselective excretion in Chinese Han population after an oral administration of racemic propranolol.

Separation and determination of bisoprolol, clonidine, disopyramide and tolazoline in control serum and in human urine was investigated by capillary isotachophoresis. The drugs were separated by using the cationic electrolyte system. viz., sodium acetate buffer (pH 4.64) (c1 = 10 mM)-beta-alanine. The compounds were almost totally isolated from serum by solid-phase extraction using a Sep-Pak C18 cartridge. The recovery of compounds varied from 87 to 99%. The linear calibration range was studied to apply the method to real human fluids. The limit of determination of the drugs was 40.0 micrograms/ml serum. The limit of determination by direct sampling for bisoprolol is 3 micrograms/ml urine.

Urine specimens containing 11 common beta blockers were processed using solid-phase extraction technology to extract the drugs from the urine matrix, then converted to their cyclic methaneboronates by treatment with methaneboronic acid in ethyl acetate. The compounds tested included acebutolol, atenolol, alprenolol, bisoprolol, betaxolol, carteolol, penbutolol, propranolol, pindolol, timolol, nadolol, sotalol, labetolol, metoprolol, and oxprenolol. The extraction efficiencies were greater than 90% for all drugs tested. The cyclic methaneboronates formed by this procedure generally possessed good chromatographic properties. The mass spectral behavior of the methaneboronates was excellent, with all compounds containing several high mass fragments and every tested compound possessing a unique mass spectrum.

A systematic study of the cross-reactivities of beta-adrenergic agonists and antagonists and their metabolites with an ELISA test designed to detect terbutaline and other beta 2-agonists has been performed in order to evaluate the applicability of this immunological test as screening method in routine human sports drug testing. Concentration response curves were calculated. IC50 values from 1.7 to 21.5 ng/mL were obtained for beta 2-agonists, and values from 3.1 to 520.8 ng/mL were obtained for most of the beta-blockers. The highest cross-reactivity was mainly depending on the amino substituent of the molecules although the structure of the aromatic ring was also important. Minor changes in the aromatic ring, such as 4-hydroxylation for propranolol, did not largely influence the IC50 value. Distribution of control activities (percentage of optical density as compared with a blank sample) of urines obtained in controlled excretion studies (70 samples) and urines collected after competition in sports in which beta-blockers are recommended to be tested (147 samples) showed a very small overlapping between the subpopulations of positive and negative samples. Cutoff values of 45 or 60% control activity were proposed for routine analysis. Sensitivity and specificity values of 92.8 and 98.8%, respectively (cutoff 45%), or 98.2 and 95.0%, respectively (cutoff 60%), were obtained. Because the known prevalence of positive results of beta-blockers and beta 2-agonists in the target population was very low, the predicted percentage of presumptive positive cases that would need further confirmation by gas chromatography-mass spectrometry was also low, accounting for a 1.48 and 5.28% (for the cutoffs of 45 and 60%, respectively) of the total number of samples to be screened by the presented ELISA test. Thus, in terms of time and cost savings, the ELISA test is a powerful tool for the purpose of screening for beta-adrenergic drugs in human urine.

We investigated the role of the vasoconstrictors endothelin-1 (ET-1) and thromboxane in renal protection by the beta 1-selective adrenoceptor antagonist, bisoprolol, in Dahl salt-sensitive rats (Dahl S) and salt-resistant rats (Dahl R). Six-week bisoprolol treatment (20 mg/kg chow) reduced systolic blood pressure (SBP) by 14% in Dahl S rats fed a high-salt (4% NaCl) diet. This BP reduction was accompanied by a decrease in aortic wall thickness. ET-1 and thromboxane released from renal cortex was significantly decreased by 17 and 30% with bisoprolol, respectively. Other prostaglandin synthesis was unaffected. Renal function such as proteinuria, N-acetyl-beta-D-glucosaminidase (NAG) excretion, and glomerular filtration rate (GFR) was not influenced by bisoprolol. Morphologic investigation showed that bisoprolol significantly improved glomerular sclerosis by 29% and attenuated arterial damage by 71%, although tubular injury was not affected. The more severe the glomerulosclerotic lesions, the greater the generation of thromboxane and ET. The arterial lesions were positively correlated to thromboxane generation. These data indicate that long-term bisoprolol treatment reduces vasoconstrictive ET-1 and thromboxane generation and that these alterations may be partly responsible for the amelioration of glomerular and arterial injury in Dahl S rats.

The pharmacokinetic handling of the beta 1 selective adrenoceptor blocking drug, bevantolol, was studied in 12 healthy volunteers. After intravenous (i.v.) administration of 50 mg of the drug, there was a biexponential decline in plasma levels with a terminal elimination half life (t1/2) of 1.9 h (range 1.4-2.3 h) and a total apparent volume of distribution at equilibrium of 62 L. After oral administration of the same dose, the bioavailability averaged 57% (range 26-98%) and peak plasma levels varied over a threefold range. On average, less than 1% of the dose was eliminated unchanged in the urine, indicating that the clearance of the drug was accounted for almost entirely by metabolism. Plasma levels after oral dosing with food showed an average 75-min delay in achievement of peak plasma levels and an average 14% increase in the extent of bioavailability of the drug. A positive correlation (r = 0.79) existed between the logarithm of the plasma bevantolol level and the percentage of reduction in postexercise heart rate. A plasma drug level of approximately 200 ng/ml produced a 10% reduction in postexercise heart rate. Pharmacological studies using guinea pig atrial and tracheal tissue demonstrated that the beta-blocking potency and beta-selectivity of bevantolol were intermediate between those of metoprolol and atenolol.

1 Nadolol excretion was studied in 24 patients with chronic renal failure. 2 The amount of nadolol excreted during the 120-h period after receiving the drug ranged from less than 1% in functionally anephric, patients up to 11.5% in patients with average creatinine clearance of 57.9 +/- 3.6 ml/min/1.73 m2. 3 Renal clearance of nadolol was found to correlate with creatinine clearance; nadolol elimination is retarded in patients with renal failure. 4 Nadolol serum half-life is prolonged in proportion to the remaining renal function. Therefore, dosage intervals in renal patients receiving nadolol should be adjusted to creatinine clearance. 5 Haemodialysis effectively reduced serum concentration of the drug; it may therefore be a useful therapy for drug intoxication.

The pharmacokinetic properties of bisoprolol-14C were studied in Wistar rats, beagle dogs, and Cynomolgus monkeys. Bisoprolol is well absorbed in these species; independent of the route of administration (i.v. or p.o.), 70-90% of the 14C-dose was recovered in urine. Faecal excretion was approximately 20% in rats and less than 10% in dogs and monkeys. Rats excreted approximately 10% of the dose in bile after i.v. as well as after oral administration. The plasma half-life of the unchanged drug was approximately 1 h in rats, 3 h in monkeys, and 5 h in dogs. The bioavailability was 40-50% in monkeys, approximately 80% in dogs, and 10% in rats. Studies in rats have shown that the drug is rapidly taken up by the tissues. After i.v. administration, high levels of radioactivity were found in lung, kidneys, liver, adrenals, spleen, pancreas, and salivary glands. After oral administration, the highest concentration occurred in the liver and kidneys. With the exception of plasma and liver, unchanged bisoprolol was the major radioactive constituent in all tissues studied. Both the blood-brain and placental barriers were penetrated, but only to a small degree. No accumulation of radioactivity in tissues was observed after repeated dosing (1 mg/kg/day). The metabolism of bisoprolol was studied in the same three animal species and in humans. The major metabolites are the products of O-dealkylation and subsequent oxidation to the corresponding carboxylic acids. The amount of bisoprolol excreted unchanged in the urine is 50-60% of the dose in humans, 30-40% in dogs, and approximately 10% in rats and monkeys.