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Purpose: The purpose of this study was to compare levels of pain and anxiety during percutaneous ultrasound-guided liver biopsy between patients receiving standard of care and those receiving standard of care plus the support of Ericksonian hypnosis., Materials and Methods: This prospective, single-center, single-blind, randomized controlled superiority trial included 70 participants. Participants were randomly assigned to either the standard of care group and received oral anxiolytic medications with reassuring conversational support, or to the experimental group, and received Ericksonian hypnosis (i.e., conversational hypnosis) in addition to standard of care. The primary outcome was the level of pain experienced during the biopsy, measured on a 10-point visual analog scale (0 indicating no pain to 10 indicating excruciating pain). Secondary outcomes included anxiety level during the biopsy, pain level within one hour of the biopsy measured using the same 10-point visual analog scale, amount of analgesic medication taken in the 24 h following the biopsy, and patient willingness to undergo another ultrasound-guided percutaneous liver biopsy in the future., Results: Thirty-six participants were included in the standard of care group, and 34 were included in the experimental group. The mean score of pain experienced during the biopsy was lower in the experimental group (2.4 ± 1.9 [standard deviation (SD)]) compared to the standard of care group (4.4 ± 2.6 [SD]) (P = 0.001). The level of anxiety experienced during the biopsy was lower in the hypnosis group (2.1 ± 1.8 [SD]) compared to the standard of care group (4.8 ± 2.4 [SD]) (P < 0.001). No significant differences in other secondary outcomes were observed between the two groups., Conclusion: The addition of Ericksonian hypnosis to standard of care reduces the pain experienced by patients during percutaneous ultrasound-guided percutaneous liver biopsy by comparison with standard of care alone., Competing Interests: Declaration of competing interest The authors have no competing interests or disclosures to declare in relation with this study., (Copyright © 2024. Published by Elsevier Masson SAS.)

Desensitization of nicotinic acetylcholine receptors (nAChRs) can be induced by overstimulation with acetylcholine (ACh) caused by an insufficient degradation of ACh after poisoning with organophosphorus compounds (OPCs). Currently, there is no generally applicable treatment for OPC poisoning that directly targets the desensitized nAChR. The bispyridinium compound MB327, an allosteric modulator of nAChR, has been shown to act as a resensitizer of nAChRs, indicating that drugs binding directly to nAChRs can have beneficial effects after OPC poisoning. However, MB327 also acts as an inhibitor of nAChRs at higher concentrations and can thus not be used for OPC poisoning treatment. Consequently, novel, more potent resensitizers are required. To successfully design novel ligands, the knowledge of the binding site is of utmost importance. Recently, we performed in silico studies to identify a new potential binding site of MB327, MB327-PAM-1, for which a more affine ligand, UNC0646, has been described. In this work, we performed ligand-based screening approaches to identify novel analogs of UNC0646 to help further understand the structure-affinity relationship of this compound class. Furthermore, we used structure-based screenings and identified compounds representing four new chemotypes binding to MB327-PAM-1. One of these compounds, cycloguanil, is the active metabolite of the antimalaria drug proguanil and shows a higher affinity towards MB327-PAM-1 than MB327. Furthermore, cycloguanil can reestablish the muscle force in soman-inhibited rat muscles. These results can act as a starting point to develop more potent resensitizers of nAChR and to close the gap in the treatment after OPC poisoning., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Poisoning with organophosphorus compounds, which can lead to a cholinergic crisis due to the inhibition of acetylcholinesterase and the subsequent accumulation of acetylcholine (ACh) in the synaptic cleft, is a serious problem for which treatment options are currently insufficient. Our approach to broadening the therapeutic spectrum is to use agents that interact directly with desensitized nicotinic acetylcholine receptors (nAChRs) in order to induce functional recovery after ACh overstimulation. Although MB327, one of the most prominent compounds investigated in this context, has already shown positive properties in terms of muscle force recovery, this compound is not suitable for use as a therapeutic agent due to its insufficient potency. By means of in silico studies based on our recently presented allosteric binding pocket at the nAChR, i.e. the MB327-PAM-1 binding site, three promising MB327 analogs with a 4-aminopyridinium ion partial structure (PTM0056, PTM0062, and PTM0063) were identified. In this study, we present the synthesis and biological evaluation of a series of new analogs of the aforementioned compounds with a 4-aminopyridinium ion partial structure (PTM0064-PTM0072), as well as hydroxy-substituted analogs of MB327 (PTMD90-0012 and PTMD90-0015) designed to substitute entropically unfavorable water clusters identified during molecular dynamics simulations. The compounds were characterized in terms of their binding affinity towards the aforementioned binding site by applying the UNC0642 MS Binding Assays and in terms of their muscle force reactivation in rat diaphragm myography. More potent compounds were identified compared to MB327, as some of them showed a higher affinity towards MB327-PAM-1 and also a higher recovery of neuromuscular transmission at lower compound concentrations. To improve the treatment of organophosphate poisoning, direct targeting of nAChRs with appropriate compounds is a key step, and this study is an important contribution to this research., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Intoxications with organophosphorus compounds (OPCs) effect a severe impairment of cholinergic neurotransmission that, as a result of overstimulation may lead to desensitization of nicotinic acetylcholine receptors (nAChRs) and finally to death due to respiratory paralysis. So far, therapeutics, that are capable to address and revert desensitized neuromuscular nAChRs into their resting, i.e. functional state are still missing. Still, among a class of compounds termed bispyridinium salts, which are characterized by the presence of two pyridinium subunits, constituents have been identified, that can counteract organophosphate poisoning by resensitizing desensitized nAChRs. According to comprehensive modeling studies this effect is mediated by an allosteric binding site at the nAChR termed MB327-PAM-1 site. For MB327, the most prominent representative of the bispyridinium salts and all other analogues studied so far, the affinity for the aforementioned binding site and the intrinsic activity measured in ex vivo and in in vivo experiments are distinctly too low, to meet the criteria to be fulfilled for therapeutic use. Hence, in order to identify new compounds with higher affinities for the MB327-PAM-1 binding site, as a basic requirement for an enhanced potency, two compound libraries, the ChemDiv library with 60 constituents and the Tocriscreen Plus library with 1280 members have been screened for hit compounds addressing the MB327-PAM-1 binding site, utilizing the [ 2 H 6 ]MB327 MS Binding Assay recently developed by us. This led to the identification of a set of 10 chemically diverse compounds, all of which exhibit an IC 50 value of ≤ 10 µM (in the [ 2 H 6 ]MB327 MS Binding Assay), which had been defined as selection criteria. The three most affine ligands, which besides a quinazoline scaffold share similarities with regard to the substitution pattern and the nature of the substituents, are UNC0638, UNC0642 and UNC0646. With binding affinities expressed as pK i values of 6.01 ± 0.10, 5.97 ± 0.05 and 6.23 ± 0.02, respectively, these compounds exceed the binding affinity of MB327 by more than one log unit. This renders them promising starting points for the development of drugs for the treatment of organophosphorus poisoning by addressing the MB327-PAM-1 binding site of the nAChR., Competing Interests: Declaration of Competing Interest Authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Intoxications with organophosphorus compounds (OPCs) based chemical warfare agents and insecticides may result in a detrimental overstimulation of muscarinic and nicotinic acetylcholine receptors evolving into a cholinergic crisis leading to death due to respiratory failure. In the case of the nicotinic acetylcholine receptor (nAChR), overstimulation leads to a desensitization of the receptor, which cannot be pharmacologically treated so far. Still, compounds interacting with the MB327 binding site of the nAChR like the bispyridinium salt MB327 have been found to re-establish the functional activity of the desensitized receptor. Only recently, a series of quinazoline derivatives with UNC0642 as one of the most prominent representatives has been identified to address the MB327 binding site of the nAChR, as well. In this study, UNC0642 has been utilized as a reporter ligand to establish new Binding Assays for this target. These assays follow the concept of MS Binding Assays for which by assessing the amount of bound reporter ligand by mass spectrometry no radiolabeled material is required. According to the results of the performed MS Binding Assays comprising saturation and competition experiments it can be concluded, that UNC0642 used as a reporter ligand addresses the MB327 binding site of the Torpedo-nAChR. This is further supported by the outcome of ex vivo studies carried out with poisoned rat diaphragm muscles as well as by in silico studies predicting the binding mode of UNC0646, an analog of UNC0642 with the highest binding affinity, in the recently proposed binding site of MB327 (MB327-PAM-1). With UNC0642 addressing the MB327 binding site of the Torpedo-nAChR, this and related quinazoline derivatives represent a promising starting point for the development of novel ligands of the nAChR as antidotes for the treatment of intoxications with organophosphorus compounds. Further, the new MS Binding Assays are a potent alternative to established assays and of particular value, as they do not require the use of radiolabeled material and are based on a commercially available compound as reporter ligand, UNC0642, exhibiting one of the highest binding affinities for the MB327 binding site known so far., Competing Interests: Declaration of Competing Interest Authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Renal cell carcinomas (RCCs) display broad resistance against conventional radio- and chemotherapies, which is due at least in part to impairments in both extrinsic and intrinsic apoptotic pathways. One important anti-apoptotic factor that is strongly overexpressed in RCCs and known to inhibit both apoptotic pathways is ARC (apoptosis repressor with a CARD domain)., Methods: Expression and subcellular distribution of ARC in RCC tissue samples and RCC cell lines were determined by immunohistochemistry and fluorescent immunohistochemistry, respectively. Extrinsic and intrinsic apoptosis signalling were induced by TRAIL (TNF-related apoptosis-inducing ligand), ABT-263 or topotecan. ARC knock-down was performed in clearCa-12 cells using lentiviral transduction of pGIPZ. shRNAmir constructs. Extrinsic respectively intrinsic apoptosis were induced by TRAIL (TNF-related apoptosis-inducing ligand), ABT263 or topotecan. Potential synergistic effects were tested by pre-treatment with topotecan and subsequent treatment with ABT263. Activation of different caspases and mitochondrial depolarisation (JC-1 staining) were analysed by flow cytometry. Protein expression of Bcl-2 family members and ARC in RCC cell lines was measured by Western blotting. Statistical analysis was performed by Student's t-test., Results: Regarding the extrinsic pathway, ARC knockdown strongly enhanced TRAIL-induced apoptosis by increasing the activation level of caspase-8. Regarding the intrinsic pathway, ARC, which was only weakly expressed in the nuclei of RCCs in vivo, exerted its anti-apoptotic effect by impairing mitochondrial activation rather than inhibiting p53. Topotecan- and ABT-263-induced apoptosis was strongly enhanced following ARC knockdown in RCC cell lines. In addition, topotecan pre-treatment enhanced ABT-263-induced apoptosis and this effect was amplified in ARC-knockdown cells., Conclusion: Taken together, our results are the first to demonstrate the importance of ARC protein in the inhibition of both the extrinsic and intrinsic pathways of apoptosis in RCCs. In this context, ARC cooperates with anti-apoptotic Bcl-2 family members to exert its strong anti-apoptotic effects and is therefore an important factor not only in the therapeutic resistance but also in future therapy strategies (i.e., Bcl-2 inhibitors) in RCC. In sum, targeting of ARC may enhance the therapeutic response in combination therapy protocols.

The bioequivalence of 2 formulations containing spironolactone and furosemide was determined. The test preparation was Spironolacton 50 plus Heumann tablets, a new generic spironolactone preparation, developed by Heumann Pharma GmbH, the reference preparation was Osyrol 50-Lasix capsules, Hoechst AG. The study was designed as a randomized 2-period, 2-sequence, crossover study. A daily dose of 50 mg spironolactone and 20 mg furosemide was administered over 5 days to 24 healthy volunteers in the fasting state. Plasma samples were assayed for spironolactone, its 2 active metabolites canrenone and 7alpha-thiomethylspirolactone, and furosemide by HPLC. Statistical analysis was performed by ANOVA and by nonparametric methods. Because spironolactone was rapidly eliminated from plasma, its pharmacokinetics could only be evaluated with regard to maximum plasma levels. This parameter did slightly miss the criteria for bioequivalence. For canrenone and 7alpha-thiomethylspirolactone bioequivalence was given. For furosemide the test formulation was found to be equivalent concerning the extent of bioavailability. Bioequivalence with regard to maximum concentrations could not be shown. However, from the point of view of pharmacodynamics, this finding may not necessarily be of clinical relevance.

The aldosterone antagonist spironolactone undergoes extensive and complex biotransformation. For investigation of bioequivalence of 2 oral spironolactone formulations, Spironolacton 50 Heumann and Aldactone 50, the pharmacokinetics and bioequivalence of the parent drug and 2 predominant active metabolites, canrenone and 7 alpha-thiomethylspirolactone, were determined in a 2-way crossover study in 24 young healthy male volunteers after multiple oral dosing of 100 mg once daily. Plasma samples were measured by a newly developed HPLC assay and individual pharmacokinetic parameters of the 3 compounds were calculated by use of noncompartmental techniques. Statistical analysis was performed by ANOVA and nonparametric methods. Spironolactone was rapidly cleared from plasma. Therefore, only Css,max and tss,max were determined. Concerning Css,max bioequivalence was found with 90% classical shortest confidence interval ranging from 80.7-112.4%. The intrasubject variability for Css,max was determined to be 28.1%. Higher and persisting concentrations were observed for the metabolites. For canrenone 90% classical shortest confidence intervals were calculated as 95.4-105.0% for AUCss,tau, as 92.9-105.8% for Css,max, and as 89.1-106.3% for peak trough fluctuation (PTF). In the case of 7 alpha-thiomethylspirolactone the values were 84.2-103.0% for AUCss,tau, 77.0-98.6% for Css,max, and 85.0-100.4% for PTF. For tss,max nonparametric 90% confidence intervals were determined as 0.00 to 1.50 h for spironolactone and canrenone and as -0.50 to 1.00 h for 7 alpha-thiomethylspirolactone. The intraindividual variability was below 30% for all pharmacokinetic parameters in the case of the metabolites. Thus, bioequivalence of the test and the reference formulation can be concluded. The study suggests the inclusion of parent compound and metabolites for bioequivalence testing of spironolactone formulations. Intraindividual subject variability was clearly diminished by investigating bioequivalence under steady-state conditions.

Eighteen volunteers have been treated with different oral formulations of butamirate citrate according to 2 randomized 2-way crossover designs. In the first study (study I) the test preparation was a syrup (Demotussol Hustensirup, Demopharm), and the reference preparation was a syrup already marketed (Sinecod Sirup, Zyma SA). A test preparation (Demotussol Tabletten) was compared to a solution (Demotussol Hustentropfen) in the second study (study II). Within the 2 study periods the volunteers received single 45 mg doses of the test and the reference formulation, respectively. Blood samples have been drawn immediately prior to each administration and at 17 sampling points within 96 h after dosing. A wash-out period of 1 week was maintained between successive drug doses. The plasma concentration of one of the main metabolites, 2-phenylbutyric acid, was determined by a validated reversed-phase HPLC method with UV detection, with a lower limit of quantification of 50 ng/ml. The following mean values have been obtained in study I (syrup preparations) for the test: AUC0-infinity 46.9 micrograms x h/ml, Cmax of 1.77 micrograms/ml at 1.1 h, t1/2 28 h and after administration of the reference: AUC0-infinity 50.4 micrograms x h/ml, Cmax 1.86 micrograms/ml, tmax 1.5 h, t1/2 26 h. In study II the following mean values have been obtained for the test preparation (tablet): AUC0-infinity 54.7 micrograms x h/ml, Cmax of 1.88 micrograms/ml at 1.1 h, t1/2 27 h and for the reference (solution): AUC0-infinity 54.5 micrograms x h/ml, Cmax 1.94 micrograms/ml, tmax 1.1 h, t1/2 26 h. Both preparations have been proven to be bioequivalent to their corresponding references regarding extent and rate of absorption.

Eighteen male volunteers have been treated with 3 different oral formulations of chlormezanone according to a randomized 3-way change-over design. The test preparation was a tablet (Krewel), reference preparation 1 was a suspension (Krewel), and reference preparation 2 was a tablet (Muskel Trancopal, Sanofi Winthrop GmbH). All preparations contained 200 mg of chlormezanone. Divided in 3 periods the volunteers received single doses of the test and the 2 reference formulations, respectively. Blood samples have been drawn immediately prior to each administration and at 21 sampling points within 144 h after dosing. A wash-out period of 2 weeks was maintained between successive drug doses. Plasma concentrations of chlormezanone were determined by a validated reversed-phase HPLC method with UV detection, with a lower limit of quantification of 0.1 microgram/ml. The following mean values have been obtained for the test preparation: AUC0-infinity 121 micrograms x h/ml, Cmax of 2.9 micrograms/ml at 1.5 h, t1/2 38 h, after administration of the suspension: AUC0-infinity 111 micrograms x h/ml, Cmax 2.6 micrograms/ml, tmax 1.5 h, t1/2 40 h, and after administration of the reference tablet: AUC0-infinity 121 micrograms x h/ml, Cmax 3.0 micrograms/ml, tmax 1.6 h, t1/2 38 h. The test preparation shows a relative bioavailability of 109% compared to the suspension and has been proven to be bioequivalent to the reference tablet with regard to extent and rate of absorption.

Twenty healthy male volunteers were treated with 2 different oral preparations of fenofibrate according to a randomized 2-way crossover design. The test preparation was Fenofibrate 250 mg retard capsules, batch No. YXF 001, provided by MTT Medical and Technological Transfer GmbH, Unterhaching, Germany. The reference preparation was Lipanthyl 250 mg retard capsules, batch No. R9110071, manufactured by Fournier Pharma, Sulzbach, Germany. On 12 consecutive days divided in 2 periods the volunteers received 6 doses of the test and reference formulation, respectively. The daily dose of 1 capsule contained 250 mg of fenofibrate and was administered together with a standardized high calory breakfast. Blood samples were taken immediately prior to each administration and at 14 points after the last administration of each period. The concentration of the pharmacologically active compound, fenofibric acid, was determined by means of HPLC with UV detection. The calibration curve was linear in the range 0.1-20.0 micrograms/ml (r = 0.99997). A lower limit of quantification of 0.1 microgram/ml was established. The following mean values were obtained after administration of the test preparation: AUC tau 184.68 microgramsh/ml; Cmax 13.11 micrograms/ml; PTF: 125.0%. After administration of the reference formulation the following values were observed: AUC tau 175.91 microgramsh/ml, Cmax 12.27 micrograms/ml, PTF: 120.0%. AUC tau, Cmax and PTF were tested for bioequivalence parametrically after logarithmic transformation. The preparations were found to be bioequivalent.

Twenty-four healthy male volunteers were treated with two different oral formulations of loperamide according to a randomized two-way cross-over design. The test preparation was Diarex Lactab (Mepha), the reference preparation Imodium 2 mg capsules. Divided in two periods the volunteers received single 8 x 2 mg (= 16mg) doses of the test and reference formulation, respectively. Blood samples were taken immediately prior to each administration and at 14 points within 60 h after the dose. A wash-out period of 1 week was interpaused between successive drug doses. The plasma concentration of the pharmacologically active compound, loperamide, was determined by HPLC with electrochemical detection. The calibration function was linear in the range 0-10.0 ng/ml. A lower limit of quantification of 0.2 ng/ml was established. The pharmacokinetic parameters Cmax and tmax were obtained directly from plasma data. The elimination constant was estimated by log-linear regression of the measured concentrations in the terminal phase. AUC was calculated by the trapezoidal rule and extrapolated to infinity. The following mean values were obtained after intake of 16 mg loperamide as film coated tablets: AUC0 infinity 62.04 ngh/ml, Cmax 3.35 ng/ml, tmax 4.08 h, t1/2 19.66 h and after administration of the capsules: AUC0 infinity 66.56 ngh/ml, Cmax 3.98 ng/ml, tmax 4.38 h, t1/2 18.43 h. The pharmacokinetic parameters AUC0 infinity and Cmax were tested for bioequivalence parametrically (two one-sided t-tests) after logarithmic transformation of data. Differences of tmax were evaluated non-parametrically. The preparations were found to be bioequivalent and, therefore, interchangeable.

Bats of the species Rhinolophus rouxi, Hipposideros lankadiva and Eptesicus fuscus were trained to discriminate between two simultaneously presented artificial insect wingbeat targets moving at different wingbeat rates. During the discrimination trials, R. rouxi, H. lankadiva and E. fuscus emitted long-CF/FM, short-CF/FM and FM echolocation sounds respectively. R. rouxi, H. lankadiva and E. fuscus were able to discriminate a difference in wingbeat rate of 2.7 Hz, 9.2 Hz and 15.8 Hz, respectively, between two simultaneously presented targets at an absolute wingbeat rate of 60 Hz, using a criterion of 75% correct responses. The performance of the different bat species is correlated with the echolocation signal design used by each species, particularly with the presence and relative duration of a narrowband component preceding a broadband FM component. These results provide behavioral evidence supporting the hypothesis that bats that use CF/FM echolocation sounds have adaptations for the perception of insect wingbeat motion and that long-CF/FM species are more specialized for this task than short CF/FM species.

A method for the determination of unconjugated terbutaline and orciprenaline in human plasma is described. The assay is based on stable isotope dilution gas chromatography/negative ion chemical ionization/mass spectrometry. An inexpensive and rapid method for preparation of stable isotope labelled analogues as well as their use in quantitative gas chromatography/mass spectrometry is shown. A highly efficient sample work-up procedure with product recoveries of more than 95% is presented. The method developed permits quantitative measurement of terbutaline and orciprenaline in human plasma down to 100 pg ml-1, using 1 ml of sample. Plasma levels of terbutaline after oral administration of 5 mg of terbutaline sulphate were estimated.

The absolute and relative bioavailability of metoclopramide following the administration of a single suppository--test (Gastrosil) and reference preparations--containing 20 mg of the pure drug or after i.v. injection of 17.8 mg was compared in 12 sex matched healthy volunteers according to an open, three-way cross-over, intra-individual design. The metoclopramide plasma levels were determined up to 32 h following rectal administration and 24 h following intravenous application using a modified and specific HPLC-assay. The areas under the concentration-time curves were either calculated to the last time-interval measured (AUC-1) by using the trapezoidal rule or by extrapolating to infinity (AUC(0-infinity] in a model-dependent manner. Pair-differences and ratios were taken for the individual AUC-values and for the maximum plasma levels (cmax-values) at the corresponding time values (tmax-values) for test and reference formulations and tested for statistical significance. The results showed the mean AUC-1 and AUC (0-infinity)-values respectively to be 10.7% and 9.5% lower for the test suppository. The mean tmax-values were found to be 21% and 11.6% lower and the mean cmax-values were found to be about 4.3% larger than the corresponding parameters for the reference formulation. The 95% Wilcoxon confidence limits for both test and reference preparation were found to range from 80.2-108.9% for all AUC-values and to lie in the region 83.5-120.3% and 57.8-100% for the cmax- and tmax-values, respectively. Thus, with respect to the pharmacokinetic target parameters, little difference can be found between the two suppository forms each containing 20 mg metoclopramide-base and under trial in this study.(ABSTRACT TRUNCATED AT 250 WORDS)

A stable isotope dilution gas chromatography/negative ion chemical ionization/mass spectrometry assay for diclofenac in human plasma is described. The preparation of (18O2)diclofenac and its use as an internal standard for quantitative gas chromatography/mass spectrometry is shown. A sample processing and derivatization sequence with product recovery of 84.7% was found. The method presented permits quantitative measurement of diclofenac in human plasma at the lower femtomole level. Plasma levels of diclofenac after administration of diclofenac gel were estimated.

An intraindividual comparative single-dose study was carried out under carefully controlled conditions on 12 healthy volunteers in order to establish the bioavailability of 5,11-dihydro-11-[(4-methyl-piperazin-1- -yl)acetyl]-6H-pyrido[2,3b][1,4]benzodiazepin-6-one dihydrochloride (pirenzepine), the active principle of newly developed tablets (Gastricur) and suspension containing 10 mg. In an additional multiple dose, cross-over study on 12 healthy volunteers, the bioequivalence of pirenzepine was investigated after administration of the newly developed vs. commercial dose-equivalent tablets. Pirenzepine was assayed from plasma by a new, highly sensitive high-performance liquid chromatography method. A 3-compartment model was taken as a basis for the calculation of the plasma concentration curves and the pharmacokinetic parameters. Following i.v. administration, the terminal elimination half-life, t 1/2, the volume of distribution, V1, and the total plasma clearance Cl were determined to be 7.7 +/- 1.4 h, 0.255 +/- 0.057 l/kg and 263.4 +/- 56.8 ml/min, respectively. From the tablet and suspension formulation the systemic availabilities were calculated to be 33.5% and 20.3%, respectively. In the multiple dose study, both tablet forms investigated were bioequivalent.

A reversed-phase high-performance liquid chromatographic (HPLC) method for the determination of four separate 1,4-benzodiazepine glucuronides in urine, plasma and bile is presented. We succeeded not only in determining the single glucuronides but also in separating the enantiomers (optical isomers) of the 1,4-benzodiazepine glucuronides. The optical isomers of the glucuronides of oxazepam and cinolazepam and of two other glucuronides of benzodiazepine metabolites could be well separated. The ratio of the isomers could be evaluated. An octadecyl reversed phase was used with a mobile phase of acetonitrile and 0.01 M orthophosphoric acid. After the initial separation, the isomers were fractionated by HPLC. After treatment with beta-glucuronidase to yield the aglycone, the separated fractions were hydrolysed to the corresponding benzophenones whose identity was confirmed by HPLC. Gas chromatography and gas chromatography-mass spectrometry demonstrated that the separated glucuronides corresponded to the enantiomeric benzodiazepines. Human urine and plasma as well as rabbit urine, plasma and bile were examined.

A stable isotope dilution gas chromatographic/negative ion chemical ionization mass spectrometric assay for diclofenac in human plasma is described. The preparation of (18O2)diclofenac and its use as an internal standard for quantitative gas chromatography/mass spectrometry is shown. A sample processing and derivatization sequence with product recovery of 84.7% was found. The method presented permits quantitative measurement of diclofenac in human plasma at the lower femtomole level. Plasma levels of diclofenac after administration of diclofenac gel were estimated.

An intraindividual comparative single-dose study was carried out under carefully controlled conditions on 12 healthy volunteers in order to establish the bioavailability of trans-4-(2-amino-3,5-dibromobenzyl)-amino-cyclohexanol (ambroxol) the active principle of newly developed tablets and drops, in comparison to a commercial i.v. preparation. In an additional single-dose, cross-over study on 12 healthy volunteers the bioequivalence of ambroxol was investigated after administration of a newly developed vs. a commercial dose-equivalent, sustained-release dosage form. Following off-line derivatisation using formaldehyde to the corresponding tetrahydroquinazoline compound, ambroxol was assayed from plasma by high-performance liquid chromatography. A 2-compartment model was taken as a basis for the calculation of the plasma concentration curves and the pharmacokinetic parameters following intravenous injection of the drug. After i.v. administration, the terminal elimination half-life, the apparent volume of distribution and the total plasma clearance were determined to be 3.72 h, 1.52 l/kg and 565 ml/min, respectively. From the tablet and drop formulations the systemic availabilities were calculated to 73 and 81%, respectively; the mean transit times were determined to be 6.8 and 5.4 h, respectively. Both sustained-release dosage forms investigated are bioequivalent.

The 2-nitroimidazole derivate Ro 07-0582 is known from experimental studies to be a very efficient radiosensitizer of hypoxic cells. Experiences with its clinical use are very limited so far. This study reports the side effects observed in the use of this drug in 12 patients. Nine of these patients were suffering from brain tumors, 3 from extracerebral tumors. In 8 of our 12 patients a sensoric polyneuropathy occurred which was strongly related to the total dose of the drug administered. Polyneuropathy was observed on the average after a total dose of 26 grams, but was already noticed at doses as low as 22 grams. It showed a good tendency for remission after termination of the drug treatment and was reversible in all patients within 4 weeks. In one patient with a brain tumor a severe organic psychosyndrome occurred which is possibly related to the drug. This side effect was also reversible. In this small group of patients the critical dose limit seems to be 29 grams. This dose can be divided into 6 fractions of 60-80 mg/kg. Up to the present knowledge this single dose is likely to give an enhancement ratio of 1,5, which would be extremly valuable for the treatment of hypoxic tumor cells.

With the aid of v. Zerssen's emotional scores the emotional condition of patients with toxic or cold thyroid adenomas was tested before operation with and without administration of oxazepam (Anxiolit retard). There was a significant improvement of the general condition not only in patients with toxic adenoma but also in patients with cold adenoma. Thus the preoperative application of Oxazepam is indicated before strumectomy to avoid stress symptoms and anxiety fits.

The efficacy of a retard preparation of allopurinol is verified by biochemical, pharmacological and clinical investigations. The action of a 300 mg allopurinol tablet, with normal release and absorption parameters, is based on the specific activity of oxypurinol, a metabolite which is formed from allopurinol according to a biotransformation process. The inhibitory action of oxypurinol on xanthine oxidase amounts to only 1/5th of that of allopurinol. On the other hand allopurinol shows an extremely short half life, so that a slow-release preparation of allopurinol seems the better way of administration to get adequate uricostatic efficacy by a single dose over a 24-hour period.

Following replacement of diphenylhydantoin (DPH) medication by a DPH preparation of different manufacture in a 41 years old woman the patient developed in spite of identical dosage clinical symptoms of overdosage which could be confirmed by EEG and determination of serum levels. In healthy volunteers the serum levels after a single oral dose of 300 mg of Epilan D Gerot and Difhydan respectively were compared. Although both preparations contained the acid of DPH significant differences in serum levels were observed. Therefore it must be concluded that the extent of the resorption differs greatly and that galenics plays a major role with regard to the bio-availability of the drug. From this single dose study no conclusions can be drawn, however, to the serum levels in long term therapy. The early clinical manifestations as well as the value of EEG and plasma level determinations in recognition of an overdosage during DPH therapy are discussed.

A method is described for allopurinol and oxipurinol assay in human serum for concentrations reached after usual therapy. The HPLC-method is based on a quick preparation of the serum samples including protein precipitation, evaporation to dryness, dissolving of the residue in citric acid and injecting the final solution on to the HPLC column. Detection limits for allopurinol are 0.05 microgram/ml serum and for oxipurinol 0.2 microgram/ml serum.

19 patients were treated with valproic acid (VPR) in combination with classical anticonvulsants (phenytoin, phenobarbitone, primidone, carbamazepine). Patients with a mean serum concentration of 340 micron moles/l showed a marked improvement as to the frequency of seizures or were even completely free from seizures, provided that the other anticonvulsants were also given in the therapeutic range. Cases showing only a slight reduction in seizure frequency or no improvement had a mean serum level of 229 micron moles/l. This investigation shows that in severe cases of epilepsy treated by combined therapy all given anticonvulsants must reach therapeutic levels to achieve effective control of seizures in most patients.

The bioavailability of two galenic formulations of 5-methoxypsoralen (5-MOP) is described. A suspension in soft gelatine capsules was tested against a micronized powder in hard gelatine capsules on six volunteers, both in a dosage of 40 mg. The comparison of the AUC shows a significant better availability of the suspension (p less than or equal to 0.05). The detection limit of 5-MOP is 2 ng/ml plasma. The described analytical method is accurate and rapid--recovery near 100%--and is suitable for routine analysis. The pharmacokinetic parameters for 5-MOP are 2.3 h for the elimination half-life and 0.344 h-1 for the elimination rate constant.

A rapid method is described for benzbromarone assay in human serum. Protein precipitation is followed by extraction of the active substance. After centrifugation the clear organic layer is evaporated to dryness, redissolved in methanol and injected on a HPLC-column. Detection limits for this method of assay are 0.1 microgram benzbromarone/ml serum. The blood level for therapeutic concentrations lies between 1 and 2.5 microgram/ml. Some pharmacokinetic data were presented. The half-life of benzbromarone is 2.6 h.

In a multiple, randomized crossover study, plasma concentrations were determined following oral single-dose administration of various phenytoin preparations. With the exception of one formulation tested (p less than or equal to 0.01), no statistically significant difference was found among the remaining preparations.