Application of physiologically based biopharmaceutics modeling to understand the impact of dissolution differences on in vivo performance of immediate release products: The case of bisoprolol

Merck KGaA observed slight differences in the dissolution of Concor® (bisoprolol) batches over the years. The purpose of this work was to assess the impact of in vitro dissolution on the simulated pharmacokinetics of bisoprolol using in vitro-in vivo relationship established with available in vitro dissolution and corresponding plasma concentrations-time data for several bisoprolol batches. A mechanistic absorption model/physiologically based pharmacokinetics model linked with a biopharmaceutics tool such as dissolution testing, namely, physiologically based biopharmaceutics modeling (PBBM), can be valuable in determining a dissolution "safe space." A PBBM for bisoprolol was built using in vitro, in silico, and clinical data. We evaluated potential influences of variability in dissolution of bisoprolol batches on its clinical performance through PBBM and virtual bioequivalence (BE) trials. We demonstrated that in vitro dissolution was not critical for the clinical performance of bisoprolol over a wide range of tested values. Based on virtual BE trials, safe space expansion was explored using hypothetical dissolution data. A formulation with in vitro dissolution reaching 70% dissolved in 15 min and 79.5% in 30 min was shown to be BE to classical fast dissolution of bisoprolol (>85% within 15 min), as point estimates and 90% confidence intervals of the maximum plasma concentration and area under the concentration-time curve were within the BE limits (0.8-1.25).

Assessment of the ecotoxicity of the pharmaceuticals bisoprolol, sotalol, and ranitidine using standard and behavioral endpoints

The pharmaceuticals bisoprolol (BIS), sotalol (SOT), and ranitidine (RAN) are among the most consumed pharmaceuticals worldwide and are frequently detected in different aquatic ecosystems. However, very few ecotoxicity data are available in the literature for them. To help fill these data gaps, toxicity tests with the algae Raphidocelis subcapitata, the macrophyte Lemna minor, the cnidarian Hydra attenuata, the crustacean Daphnia similis, and the fish Danio rerio were performed for assessing the ecotoxicity of these pharmaceuticals. Standard, as well as non-standard endpoint, was evaluated, including the locomotor behavior of D. rerio larvae. Results obtained for SOT and RAN showed that acute adverse effects are not expected to occur on aquatic organisms at the concentrations at which these pharmaceuticals are usually found in fresh surface waters. On the other hand, BIS was classified as hazardous to the environment in the acute III category. Locomotor behavior of D. rerio larvae was not affected by BIS and RAN. A disturbance on the total swimming distance at the dark cycle was observed only for larvae exposed to the highest test concentration of 500 mg L^-1 of SOT. D. similis reproduction was affected by BIS with an EC₁₀ of 3.6 (0.1-34.0) mg L^-1. A risk quotient (RQ) of 0.04 was calculated for BIS in fresh surface water, considering a worst-case scenario. To the best of our knowledge, this study presents the first chronic toxicity data with BIS on non-target organisms.

EFFECT OF HYDROPHILIC AND HYDROPHOBIC POLYMER ON IN VITRO DISSOLUTION AND PERMEATION OF BISOPROLOL FUMARATE THROUGH TRANSDERMAL PATCH

A matrix transdermal patch of bisoprolol fumarate was formulated with different concentrations of Eudragit RS 100 and Methocel E5 with PEG 400 as plasticizer by solvent evaporation technique. Tween 80 was added to the optimized patch to evaluate the effect of permeation enhancer at different concentration through the excised rabbit's skin. The patches were analyzed for weight variation, drug content, swelling index, erosion studies, moisture content, moisture uptake, water vapor transmission rate (WVTR) and water vapor permeability (WVP). In vitro dissolution test was carried out in USP dissolution apparatus V to select the optimized formulation. In vitr skin permeation studies were done in Franz diffusion cell using rabbit skin as a model membrane. The cumulative drug release and flux were determined to compare the result of test patches with a control patch. The greatest enhancement ratio (ER) was obtained in F03-PE with 30% Tween 80. F03-PE seemed to follow zero order kinetics with super case II mechanism of drug release. Statistical ANOVA suggested that there was a significant difference in formulations, steady flux and cumulative permeation rate at different Tween 80 concentrations.

Preparation of bisoprolol fumarate nasal spray and its nasal delivery in rats

The aim of the present work was to prepare a nasal spray of bisoprolol fumarate (BF). The Pharmacokinetics and relative bioavailability of the BF nasal formulation were evaluated in Wistar rats. The BF nasal spray after administration exhibited very fast absorption and higher plasma drug concentration. The maximum plasma concentration (C(max)) and the time to reach it (T(max)) were 409.5 ng/ml and 3.6 min for the BF nasal spray, 39.4 ng/ml and 26.7 min for the drug solution, respectively. The bioavailability of the BF nasal spray was greater than 1500.0%. Meantime, the effect of the BF nasal spray on nasal mucociliary movement was also studied with a toad palate model. The BF nasal preparation showed minor ciliotoxicity, but the adverse effect was temporary and reversible.

IN VITRO TESTING OF XANTHAN/LIGNIN HYDROGELS AS CARRIERS FOR CONTROLLED DELIVERY OF BISOPROLOL FUMARATE

AIM

To develop sustained release matrix tablets based on xanthan as highly water-soluble, cost-effective, non-toxic, easily available, and suitable hydrophilic systems.

MATERIAL AND METHODS

Xanthan and lignin epoxy-modified resin (LER) mixture were crosslinked using epichlorohydrin as crosslinking agent leading to superabsorbent hydrogels with high swelling rate in aqueous mediums.

RESULTS AND CONCLUSIONS

These hydrogels were tested as carries by the loading/delivery behaviour of bisoprolol fumarate in physiological conditions and based on the obtained results these hydrogels may show interest for application in medical and pharmaceutical areas. The amount of drug loaded in polymer networks was found to be ranging between 14.4% and 19.2%. Drug release was retarded and the release mechanism of the active principle was found to depend on matrix composition.

Spectrophotometric method for estimation of bisoprolol fumarate in tablets

Bisoprolol fumarate is prescribed for the treatment of hypertension and angina pectoris.

AIM

The purpose of this study was to develop a simple, sensitive, accurate, and reproducible method for estimation of bisoprolol fumarate in tablets.

MATERIAL AND METHODS

The proposed method was based on a yellow colored complex formed with tropaeolin 00, extractable in dichloromethane with maximum absorbance at 412 nm. The method was validated statistically.

RESULTS

The linearity domain was observed in the concentration of 5-30 microg/ml. The recovery studies confirmed the accuracy of the proposed method.

CONCLUSIONS

The proposed method can be applied for the routine analysis of bisoprolol from formulations.

Validation of a spectrophotometric assay method for bisoprolol using picric acid

Bisoprolol is a drug belonging to beta blockers drugs used primarily for the treatment of cardiovascular diseases.

AIM

A spectrophotometric method for quantitative determination of bisoprolol was developed based on the formation of a complex combination between bisoprolol and picric acid.

MATERIAL AND METHODS

The complex combination of bisoprolol and picric acid has a maximum absorbance peak at 420 nm. Optimum working conditions were established and the method was validated.

RESULTS

The method presented a good linearity in the concentration range 5-120 microg/ml (regression coefficient r2 = 0.9992). The RSD for the precision of the method was 1.74 and for the intermediate precision 1.43, and recovery values ranged between 98.25-101.48%.

CONCLUSIONS

The proposed and validated spectrophotometric method for the determination of bisoprolol is simple and cost effective.

Microbial transformation of pharmaceuticals naproxen, bisoprolol, and diclofenac in aerobic and anaerobic environments

Although biotransformation is generally considered to be the main process by which to remove pharmaceuticals, both in sewage treatment plants and in aquatic environments, quantitative information on specific compounds is scarce. In this study, the transformations of diclofenac (DCF), naproxen (NPX), and bisoprolol (BSP) were studied under aerobic and anaerobic conditions using inocula taken from activated and digested sludge processes, respectively. Whereas concentration decays were monitored by LC-tandem mass spectrometry, oxygen consumption and methane production were used for the evaluation of the performance of overall conditions. DCF was recalcitrant against both aerobic and anaerobic biotransformation. More than one third of the BSP disappeared under aerobic conditions, whereas only 14% was anaerobically biotransformed in 161 days. Under aerobic conditions, complete removal of NPX was evident within 14 days, but anaerobic transformation was also efficient. Formation of 6-O-desmethylnaproxen, a previously reported aerobic metabolite, was also detected under anaerobic conditions and persisted for 161 days.

[Chiral separation of bisoprolol using high performance liquid chromatography with amylose chiral stationary phase]

A high performance liquid chromatographic (HPLC) method using amylase chiral stationary phase for the separation of bisoprolol enantiomers has been developed. Tris (3,5-dimethylphenyl carbamate) amylase chiral stationary phase was used in the normal-phase mode. The effects of the concentration of organic solvents (iso-propanol and ethanol), flow rate and column temperature on the enantiomer separation were studied systematically. The best separation was obtained with hexane-ethanol-diethyl amine (88 : 12 : 0.1, v/v/v) as mobile phase at 20 degrees C. The optimal flow rate was 0.6 mL/min. The detection wavelength was set at 270 nm. By using this method, the enantiomers of bisoprolol can be separated quickly and easily.

Membrane electrodes for determination of some beta-blocker drugs

Five poly(vinyl chloride) (PVC) matrix membrane electrodes responsive to the beta-blockers atenolol (AT), bisoprolol fumarate (BI), timolol maleate (TI), and levobunolol HCl (LV) were developed and characterized. A precipitation-based technique with ammonium reineckate anion as an electroactive material in PVC matrix with AT, BI, TI, and LV cations was used for fabrication of Electrodes 1-4, respectively. Electrode 5 fabrication was based on precipitation of LV cation with tungstophosphate anion as an electroactive material. Fast and stable Nernstian responses at 1 x 10(-2)-1 x 10(-7) M for different beta-blockers over the pH range of 2-8 were found for these electrodes, which were evaluated according to International Union of Pure and Applied Chemistry recommendations. The method was successively applied for the determination of beta-blockers in their pharmaceutical formulations. Validation of the method according to quality assurance standards showed the suitability of the proposed electrodes for use in the quality control assessment of these drugs. The recoveries for the determination of the beta-blocker drugs by the 5 proposed selective electrodes were 100.1 +/- 0.7, 99.9 +/- 0.8, 100.0 +/-1.1, 100.5 +/- 1.1, and 100.6 +/- 0.7% for Sensors 1-5, respectively. Statistical comparison between the results obtained by this method and the official method of the drugs was performed and no significant difference was found.

Simultaneous determination of ten antiarrhythic drugs and a metabolite in human plasma by liquid chromatography—tandem mass spectrometry

A simple, accurate and selective LC-MS/MS method was developed and validated for simultaneous quantification of ten antiarrhythic drugs (diltiazem, amiodarone, mexiletine, propranolol, sotalol, verapamil, bisoprolol, metoprolol, atenolol, carvedilol) and a metabolite (norverapamil) in human plasma. Plasma samples were simply pretreated with acetonitrile for deproteinization. Chromatographic separation was performed on a Capcell C(18) column (50mmx2.0mm, 5microm) using a gradient mixture of acetonitrile and water (both containing 0.02% formic acid) as a mobile phase at flow rate of 0.3ml/min. The analytes were protonated in the positive electrospray ionization (ESI) interface and detected in multiple reaction monitoring (MRM) mode. Calibration curves were linear over wide ranges from sub- to over-therapeutic concentration in plasma for all analytes. Intra- and inter-batch precision of analysis was <12.0%, accuracy ranged from 90% to 110%, average recovery from 85.0% to 99.7%. The validated method was successfully applied to therapeutic drug monitoring (TDM) of antiarrhythic drugs in routine clinical practice.

Enantioanalysis of Bisoprolol in Human Plasma with a Macrocyclic Antibiotic HPLC Chiral Column Using Fluorescence Detection and Solid Phase Extraction

A sensitive, enantioselective, high-performance liquid chromatographic (HPLC) method was developed and validated to determine S-(-)- and R-(+)-bisoprolol in human plasma. Baseline resolution was achieved using the teicoplanin macrocyclic antibiotic chiral stationary phase (CSP) known as Chirobiotic T with a polar ionic mobile phase (PIM) consisting of methanol-glacial acetic acid-triethylamine (100 : 0.02 : 0.025, v/v/v) at a flow rate of 1.5 ml/min and fluorescence detection set at 275 nm for excitation and 305 nm for emission. All analyses with S-(-)-atenolol as the internal standard were conducted at ambient temperature. The assay involved the use of a solid-phase extraction procedure for human plasma samples prior to HPLC analysis. The C18 cartridge gave good recovery rates for both enantiomers without any interference. The method was validated over the range of 20-200 ng/ml for each enantiomer concentration. Recovery rates for S-(-)- and R-(+)-bisoprolol enantiomers were in the range of 95-102%. The method proved to be precise (within-run precision expressed as % RSD ranged from 1.0-6.2% and between-run precision ranged from 0.9-6.7%) and accurate (within-run accuracies expressed as percentage error ranged from 0.2-4.8% and between-run accuracies ranged from 0.3-1.7%). The limit of quantitation and limit of detection for each enantiomer in human plasma were 20 and 5 ng/ml, respectively.

A novel transdermal patch incorporating isosorbide dinitrate with bisoprolol: in vitro and in vivo characterization

The combination therapy of nitrate and selective beta-adrenoceptor antagonist has shown benefits for treatment of hypertension and heart disease than either drug alone. The objectives of the present study were to define effects on the anti-hypertension activity and pharmacokinetics of a novel transdermal patch incorporating isosorbide dinitrate (ISDN) with bisoprolol (BP). The 3:2 ratio of ISDN to BP (mg/mg) in the transdermal patches exhibited better anti-hypertension effect synergistically with a similar inhibiting heart rates effect to that of BP alone in renovascular hypertensive rats, and was therefore selected as a final formulation. The in vitro transdermal penetration of both ISDN and BP from the patches displayed a zero-order process, and the penetration rate constants were 7.4 microg/(cm(2)h) for ISDN, and 5.9 microg/(cm(2)h) for BP, respectively. After transdermal administration at single dose or multiple doses, the synergistic anti-hypertension effect was confirmed in spontaneously hypertensive rats also. The effect of each patch lasts for 3 days, and increased with the total dose of two drugs (2mg/cm(2), ISDN:BP=3:2, mg/mg), showing a dose dependant manner. After transdermal administration to rabbits, the absolute bioavailabilities were 33.6% for ISDN, and 31.3% for BP, respectively. The maximal concentrations (C(max)) of both drugs were significantly reduced while the areas under the plasma concentration-time curve (AUC), and mean residence times (MRT) were evidently increased and extended, respectively. As a patient-friendly, convenient, and multi-day dosing therapeutic system, the transdermal patches incorporating ISDN and BP could be promising for prevention and treatment of hypertension.

Nebivolol, bucindolol, metoprolol and carvedilol are devoid of intrinsic sympathomimetic activity in human myocardium

1. The present study investigated whether or not there may be differences in the direct cardiac actions of the novel, highly beta(1)-selective adrenoceptor antagonist nebivolol (NEB) in comparison to metoprolol (MET), bisoprolol (BIS), carvedilol (CAR) and bucindolol (BUC) in human myocardium (n=9). 2. The rank order of beta(1)-selectivity as judged by competition experiments to (3)H-CGP 12.1777 in the presence of CGP 207.12 A (300 nmol l(-1), K(i)beta(2)) or ICI 118.551 (50 nmol l(-1), K(i)beta(1)) were NEB(K(i)beta(2)/K(i)beta(1): 40.7) > BIS(15.6) > MET(4.23) > CAR(0.73) > BUC(0.49). 3. The rank order of the negative inotropic potency of the beta-adrenoceptor antagonists measured in left ventricular trabeculae (dilated cardiomyopathy, DCM) as judged by the concentration needed to induce a 50% decrease in isoprenaline (1 micromol l(-1))-stimulated force (IC(50)) was: MET (0.6 micromol l(-1)) > CAR (4.1 micromol l(-1)) > NEB (7.0 micromol l(-1)). 4. NEB, BUC, MET and CAR did not not exert an intrinsic sympathomimetic activity (ISA) as determined by measurements of force development in forskolin (0.3 micromol l(-1)) pre-treated left ventricular trabeculae, nor by measuring adenylate cyclase activity in forskolin (0.3 micromol l(-1))-stimulated assays (crude membranes). This also holds true for radioligand binding assays with or without guanine nucleotide guanyl-5'-yl imidodiphosphate (Gpp(NH)p). 5. Although all studied beta-adrenoceptor antagonists lack intrinsic sympathomimetic activity (ISA), they differ in the beta(1)-selectivity as well as in their direct negative inotropic action. These differences as well as the mode of extracardiac action may have an impact on outcome of patients treated with beta-adrenoceptor antagonists.

Asymmetric synthesis and preliminary evaluation of (R)- and (S)-[11C]bisoprolol, a putative beta1-selective adrenoceptor radioligand

(+/-)-1-[4-(2-Isopropoxyethoxymethyl)-phenoxy]-3-isopropylamino-2-propanol (bisoprolol) is a potent, clinically used beta(1)-adrenergic agent. (R)-(+) and (S)-(-) enantiomers of bisoprolol were labelled with carbon-11 (t(1/2)=20.4 min) as putative tracers for the non-invasive assessment of the beta(1)-adrenoceptor subtype in the human heart and brain with positron emission tomography (PET). The radiosynthesis consisted of reductive alkylation of des-iso-propyl precursor with [2-11C]acetone in the presence of sodium cyanoborohydride and acetic acid. The stereo-conservative synthesis of (R)-(+) and (S)-(-)-1-[4-(2-isopropoxyethoxymethyl)-phenoxy]-3-amino-2-propanol to be used as the precursors for the radiosynthesis of [11C]bisoprolol enantiomers was readily accomplished by the use of the corresponding chiral epoxide in three steps starting from the commercially available hydroxybenzyl alcohol. The final labelled product (either (+) or (-)-1-[4-(-isopropoxyethoxymethyl)-phenoxy]-3- [11C]isopropylamino-2-propanol) was obtained in 99% radiochemical purity in 30 min with 15+/-5% (EOS, non-decay corrected) radiochemical yield and 3.5+/-1 Ci/micromol specific radioactivity. Preliminary biological evaluation of the tracer in rats showed that about 30% of heart uptake of [11C](S)-bisoprolol is due to specific binding. The high non-specific uptake in lung might mask the heart uptake, thus precluding the use of [11C](S)-bisoprolol for heart and lung studies by PET. The remarkably high uptake of the tracer in rat brain areas rich of beta-adrenergic receptors such as pituitary (1.8+/-0.3% I.D. at 30 min) was blocked by pre-treatment with the beta-adrenergic antagonists propranolol (45%) and bisoprolol (51%, p<0.05). [11C](S)-bisoprolol deserves further evaluation in other animal models as a putative beta(1) selective radioligand for in vivo investigation of central adrenoceptors.