bluuebunny/crossref_metadata_2025_split huggingface dataset:
The influence of prostaglandin E2 and indomethacin on the renal corticomedullary solute gradient in the rat
Authors: Haylor J , Lote C J 
Published: April 2011

Abstract
The renal corticomedullary solute gradient and the urinary excretion of fluid and solute were determined during a saline infusion in anaesthetized and conscious rats. In the anaesthetized group the influence of PGE2 (100 ng min−1) given by a local renal infusion was investigated. In the conscious group (where prostaglandin synthesis does not contribute to renal blood flow) the effect of indomethacin (i.v. 10 mg kg−1) was determined. Following PGE2 infusion the corticomedullary gradient for sodium was depressed, equalizing the sodium concentration between the papilla tip and the final urine. Sodium output and urine flow were elevated, but both urinary and gradient changes could be dissociated from any increase in renal blood flow, assessed by PAH clearance. Following treatment with the prostaglandin synthetase inhibitor indomethacin in the conscious rat, the corticomedullary osmotic gradient was elevated while the urine flow was reduced. This increase in the gradient produced by indomethacin was, however, found to be independent of the decrease in urine flow. The results of the present experiments are consistent with the hypothesis that prostaglandin synthesis helps to determine the renal corticomedullary osmotic gradient, and does so by a mechanism unlikely to involve changes in renal blood flow or tubular flow rate: a permeability hypothesis is proposed.
Analysis of the permeation and mechanical characteristics of some aqueous-based film coating systems
Authors: Okhamafe Augustine O , York Peter 
Published: April 2011

Abstract
The moisture permeability and mechanical properties of some aqueous-based free films have been evaluated using sorption-desorption and stress-strain techniques, respectively. These properties for blends of two film-formers—hydroxypropyl methylcellulose and polyvinyl alcohol—have been compared with those of hydroxypropyl methylcellulose films plasticized with polyethylene glycols. The polyethylene glycols generally increased the moisture permeability of hydroxypropyl methylcellulose films while polyvinyl alcohol decreased it. Both polyvinyl alcohol and the polyethylene glycols lowered tensile strength at break and Young’s modulus but the effects of the polyethylene glycols were more pronounced. These results are discussed in terms of structural interactions between film components. All film systems evaluated, except that containing hydroxypropyl methylcellulose alone, exhibited a degree of anisotropy, a phenomenon with potentially adverse consequences in tablet film coating.
The deamination of n-pentylamine by monoamine oxidase and a semicarbazide-sensitive amine oxidase of rat heart
Authors: Guffroy Christian , Fowler Christopher J , Benedetti Margherita Strolin 
Published: April 2011

Abstract
n-Pentylamine is deaminated by homogenates of rat heart. Clorgyline inhibition curves at 10 and 100 μM n-pentylamine indicated that this substrate was deaminated by MAO-A, -B and a clorgyline-resistant amine oxidase sensitive to inhibition by semicarbazide. These results have been compared with two other commonly used monoamine substrates, β-phenethylamine and benzylamine.
Dilazep: an inhibitor of adenosine uptake with intrinsic calcium antagonistic properties
Authors: Tonini M , Perucca E , Manzo L , Marcoli M , D'Angelo L , Saltarelli P , Onori L 
Published: April 2011

Abstract
Concentrations of dilazep which were ineffective in altering the muscular tone of the guinea-pig taenia caeci (0·03, 0·3 μM) or the phasic mechanical activity of the rabbit proximal ileum (0·03 μM) markedly potentiated the inhibitory action of adenosine on both these parameters. Dilazep, 0·3 μM or greater, dose-dependently inhibited the mechanical activity of the proximal ileum. This inhibitory action was probably mediated by more than one mechanism, as shown by the fact that theophylline (50,100 μM) antagonized the effect at lower dilazep concentrations (up to 3 μM) leaving essentially unchanged the response to higher concentrations (6, 10 μM). Similarly, the responses to low doses of dilazep were reduced after desensitization of the organ to adenosine, whilst the responses to higher doses were unaffected by this procedure. In a Ca2+-free, high-K+ medium, dilazep (1-10 μM) caused a parallel shift to the right of the Ca2+-induced contractions of the guinea-pig taenia caeci. Adenosine showed only slight Ca2+-antagonistic properties within the mM range of concentrations. These findings suggest that, at the higher concentrations tested, dilazep exhibits Ca2+-antagonistic properties unrelated to its adenosine-mediated mode of action.
The role of disintegrants in hard-gelatin capsules
Authors: Botzolakis J E , Augsburger L L 
Published: April 2011

Abstract
Experiments were designed to investigate the efficacy of various disintegrants on hydrochlorothiazide dissolution from soluble (lactose) and insoluble (dicalcium phosphate) fillers at various lubricant concentrations and compression forces. Capsule fill weights as well as slug hardness appeared to be influenced by the addition of disintegrants. Disintegration times were not always in rank order agreement with dissolution data. Analysis of the dissolution data by 3-way analysis of variance revealed that all the main factors (disintegrant, compression force, lubricant and/or diluent) and their interactions were significant. The presence of interactions limits the conclusions to be drawn; however, an assessment of the averaged effect of each factor separately revealed several important relationships. A compression force effect was evident in most cases at the lower disintegrant concentration, and lower lubricant concentrations or a more soluble filler appeared to require lesser amounts of disintegrant. The magnitude and order of effectiveness of the disintegrants were altered when the filler system was changed from lactose to dicalcium phosphate.
The evaluation of an automatic system for filling liquids into hard gelatin capsules
Authors: McTaggart C , Wood R , Bedford K , Walker S E 
Published: April 2011

Abstract
A system is described in which an intermittent motion powder filling capsule machine is modified to fill liquids into hard gelatin capsules suitable for pilot scale or small production batches. The system is shown to be suitable for filling materials covering a wide range of viscosities and to give excellent fill weight uniformity which is largely independent of operating conditions. The process is clean and trouble-free.
Amorphous spray-dried hydroflumethiazide-polyvinylpyrrolidone systems: Physicochemical properties
Authors: Corrigan O I , Holohan E M 
Published: April 2011

Abstract
Hydroflumethiazide was spray-dried with polyvinylpyrrolidone (PVP) to produce products containing 0–30% PVP. These systems were amorphous and differed from previously prepared coprecipitates of similar composition. Differential scanning calorimetry (DSC) suggested that at low PVP weight fractions both amorphous drug and an amorphous drug-PVP complex can be present in spray-dried systems. The apparent solubility of hydroflumethiazide in spray-dried products increased with increasing PVP content reaching a plateau value approximately four times that of the pure crystalline drug. The estimated free energy and entropy of the spray-dried drug were greater than that of crystalline drug and also increased with increasing PVP content. Dissolution studies with compressed discs supported the apparent solubility data. The results suggest that amorphous phases having different orders of organization are formed in spray-dried systems with increasing PVP content.
Controlled release of radioprotective agents from matrix tablets—effect of preparative conditions on release rates
Authors: Benita S , Shani J , Abdulrazik M , Samuni A 
Published: April 2011

Abstract
Release rates of radioprotective agents from insoluble matrix tablets were measured as a function of ethylcellulose/stearic acid ratio and active ingredient concentration in the matrix. The influence of the compacting pressure applied during tablet formation on the release of these aminothiol compounds was also examined. The kinetic data conformed with the Higuchi square root equation and first order release. As both plots were linearly acceptable, a statistical method for release mechanism identification using the kinetic experimental results obtained without any further transformation was used. This non-linear regression search procedure accompanied by the χ2-square test has shown that aminothiol release from the matrix tablets definitely follows the Higuchi square root equation. Increasing the ethylcellulose amount in the matrix consequently improves the degree of wettability and leads to a faster rate of solvent penetration. This tends to release the aminothiols more rapidly from the matrix tablets. Solvent penetration, which also follows a square root of time relationship, is probably the rate-limiting factor in the release process. The linear increase in release rates of the aminothiols observed with ethylcellulose concentration is explained by a parallel increase in the porosity of the matrix tablets. Increase in the drug concentration in the tablet increases the cysteine hydrochloride release rate and decreases the cysteamine hydrochloride release rate. A similar effect was also observed by applying increasing compacting pressure during matrix tablet formation. It was suggested that these two experimental factors differently affect the internal structure of the matrix during the preparation process. In the presence of cysteine hydrochloride larger porosities and smaller tortuosities are produced in the matrix leading to an increase in release rate. On the other hand, in the presence of cysteamine hydrochloride smaller porosities and larger tortuosities are formed in the matrix leading to a decrease in the release rate with increasing aminothiol concentration and compacting pressure respectively.
Effect of chloroquine and some other antimalarials on the immune mechanism in experimental animals
Authors: Bhattacharya S K , Pillai C R , Mathur M , Sen P 
Published: April 2011

Abstract
The effects of chloroquine and some other antimalarials on the immune responses in experimental animals have been examined. Chloroquine and quinine caused significant decrease of serum anti−SRBC haemagglutination titre. Chloroquine lowered the serum IgM level and also reduced plaque−forming cells in the spleen of mice. The delayed−type hypersensitivity responses to SRBC and the passive cutaneous anaphylaxis were also diminished in rats treated with chloroquine. Thus, the immunosuppressant activity of chloroquine may explain its efficacy in various types of immune disorders.
Parallel bioassay of physalaemin and hylambatin on smooth muscle preparations and blood pressure
Authors: Erspamer G Falconieri , Mazzanti G , Yasuhara T , Nakajima T 
Published: April 2011

Abstract
Hylambatin, a novel tachykinin endecapeptide isolated from the skin of the African frog Hylambates maculatus, must be ascribed to the physalaemin subfamily. It differs structurally from all other known tachykinins mainly in having a methionine residue replacing the usual leucine residue at position 2 from the C―terminus. In parallel bioassay on a number of in―vitro and in―vivo test objects, hylambatin and physalaemin were nearly indistinguishable from each other, with few moderate quantitative differences.
Rheology of pharmaceutical granulations
Authors: Schildcrout Sigmund A 
Published: April 2011

Abstract
The rheological transformations that take place when granulating fluid is added to pharmaceutical powders have been monitored by means of a laboratory scale (approx. 50 g amounts) torque rheometer. The three formulations studied, based on lactose, sulfadiazine, and benoxaprofen, had common characteristics in that each passed through a granulation peak of maximum torque. In the zone immediately before the peak the granules were growing, while after it the material had properties of a cohesive, viscoelastic mass. Therefore, the rheological state of the material under process is not specified by a single torque reading, but by the rheological history of the granulation.
The solubility of 17 β-oestradiol in aqueous polyethylene glycol 400
Authors: Groves M J , Bassett B , Sheth V 
Published: April 2011

Abstract
The solubility of 17 β-oestradiol (E2) in aqueous solutions of polyethylene glycol (PEG) 400 has been measured at 35 °C. Up to 80% w/w PEG the solubility data conform to a log linear equation In S = In Sw + fø where S is the E2 concentration in the water/cosolvent mixture, Sw is E2 solubility in water, f is the weight fraction of PEG 400 and ø is a parameter representing the solubilizing power of the cosolvent for the drug. Above 80% PEG the relationship becomes less convincing, with significant deviation from anticipated values. Reasons for these aberrations are discussed. It is suggested that conformational changes may be induced in the PEG by the addition of small quantities of water. Deviations noted for the melting point, viscosity and density data of PEG 400-water solutions may also confirm this suggestion.
A nuclear magnetic resonance (nmr) investigation of the micellar structure of a long-chain non-ionic surfactant
Authors: Elworthy P H , Patel M S 
Published: April 2011

Abstract
Peak integrals, peak widths at half-height (Δν1/2), spin-lattice relaxation times (T1), and chemical shifts (δ) of the alkyl and oxyethylene protons of CH3(CH2)21[OCH2CH2]27OH (C22E27) were measured in D2O at various temperatures. The peak integrals, Δν1/2, and δ values of the alkyl protons showed a large dependence on temperature below 313K, while the values for the oxyethylene protons were unaffected by temperature. These observations were explained by considering an intrusion of some oxyethylene groups into the hydrocarbon core of the micelle.
Characterization of β-adrenoceptors mediating relaxation of the guinea-pig ileum
Authors: Grassby Paul F , Broadley Kenneth J 
Published: April 2011

Abstract
Relaxation responses to sympathomimetic amines were recorded in potassium-contracted segments of guinea-pig ileum. Experiments were performed in the presence of phentolamine (5 times 10−6 m) to eliminate β-adrenoceptor-mediated effects. Metanephrine (10−5 m) and desmethylimipramine (5 times 10−7 m) were also present to prevent extraneuronal and neuronal uptake respectively. A potency order (-)-isoprenaline &gt; (-)-noradrenaline &gt; (-)-adrenaline was established, indicating a β1-adrenoceptor involvement for this relaxation. The potency of salbutamol (β2-selective) relative to isoprenaline in the ileum compared closely with its relative potency in isolated cardiac tissues (β1) but differed significantly from the value in lung parenchymal strips and vas deferens (β2). The pA2 values for antagonism of selective agonists (-)-noradrenaline (β1-selective) and fenoterol (β2-selective) by practolol (β1-selective) were identical, indicating a single β1-adrenoceptor population. The pA2 values for antagonism of these agonists by ICI 118,551 (β2-selective) were also identical and compatible with a β1-adrenoceptor population. Relaxation of the guinea-pig ileum is therefore mediated via a homogeneous population of β1-adrenoceptors.
Psychopharmacological investigation of the monoamine oxidase inhibitory activity of molindone, a dihydroindolone neuroleptic
Authors: Balsara J J , Gada V P , Nandal N V , Chandorkar A G 
Published: April 2011

Abstract
24 h pretreatment with molindone enhanced the behavioural effects of l-dopa and 5-HTP, precursors of biogenic amines (catecholamines and 5-HT respectively) preferentially deaminated by MAO-A, confirming that a metabolite of molindone inhibits MAO-A. 24 h pretreatment with molindone enhanced the behavioural effects of tryptamine and antagonized reserpine-induced ptosis, and in molindone-pretreated rats l-tryptophan induced behavioural effects, probably because of the MAO-A inhibitory activity exerted by a metabolite of molindone. Since 24 h pretreatment with molindone, unlike 30 min pretreatment with clomipramine, failed to antagonize fenfluramine and p-chloramphetamine-induced behavioural syndromes, it suggests that molindone and/or its metabolites most probably do not exert 5-HT neuronal uptake blocking activity and the potentiation of 5-HTP-induced behavioural syndrome is due to a metabolite’s MAO-A inhibitory activity. As 2 h pretreatment with molindone induced catalepsy and antagonized apomorphine-induced climbing behaviour in mice and stereotypy in rats, while 24 h pretreatment failed to induce catalepsy and to antagonize apomorphine-induced behaviour, it appears that, at 24 h, the tissue levels of molindone are inadequate to block postsynaptic striatal and mesolimbic DA receptors and that, though a metabolite of molindone is biologically active so far as inhibition of MAO-A is concerned, the metabolites are devoid of neuroleptic activity. Further, since 2 h pretreatment with molindone failed to enhance the behavioural effects of l-dopa, it suggests that at 2 h the degree of MAO-A inhibition induced by molindone and/or the metabolite is not sufficient to counteract the neuroleptic activity of the parent compound.
Plasto-elasticity and tableting of paracetamol, Avicel and other powders
Authors: Malamataris S , Baie S bin , Pilpel N 
Published: April 2011

Abstract
The plasto-elasticity of mixtures of paracetamol and Avicel powders and the tensile strengths of their tablets varied with the sizes of the particles and with the compositions of the mixtures. Tests made on these and other tablets showed that the logarithms of their strengths were inversely proportional to the ratios of the samples’ elastic recovery: plastic compression; they exhibited lamination or capping when this ratio was greater than 9.
Complexation of tetracylines with metal ions in relation to photosensitization
Authors: Riaz M , Pilpel N 
Published: April 2011

Abstract
It has been shown by spectroscopy and by a Photosensitive Index method, involving measurements of interfacial tension, that Cu2+ and Ni2+ form 2:1 complexes with oxytetracycline and 1:1 complexes with demethylchlortetracycline, Fe2+, Zn2+, Mg2+ and Ca2+ form weaker 1:1 complexes with both drugs. The possibility is discussed of using metal ions to reduce photosensitization by tetracyclines in-vivo.
The proinsulin content of commercial bovine insulin formulations
Authors: Sutcliffe N , Bristow A F 
Published: April 2011

Abstract
The proinsulin-like immunoreactivity (PLI) content of traditional and highly purified bovine insulin preparations sold by three insulin manufacturers in the UK has been estimated by radioimmunoassay. We report the PLI content of 22 batches of traditional insulin products and 32 of highly purified insulin, marketed between March 1980 and March 1983. Estimates of the PLI content of traditional insulins ranged from 2290 to 48400 parts per million (ppm). In contrast the estimated PLI content of the highly purified insulins varied between less than 1 ppm and 1160 ppm, although more recent batches prepared by current methodology contained less than 10 ppm of PLI. We conclude that highly purified bovine insulin on sale in the UK may now be expected to contain less than 10 ppm of proinsulin-like immunoreactivity.
Diflunisal and blood acid base status in the rabbit
Authors: Smith J E , Bradshaw E G , Pleuvry B J 
Published: April 2011

Abstract
Both diflunisal and acetylsalicylic acid given orally caused respiratory alkalosis and metabolic acidosis. However the fall in standard bicarbonate was much less in diflunisal-treated rabbits and pH in these animals remained elevated for the duration of the experiment. Whilst the severity of the fall in arterialized venous PCO2 was a good indicator of the degree of acetylsalicylic acid intoxication this was not the case for diflunisal as fatalities occurred with trivial changes in PCO2. Diflunisal toxicity was associated with markedly elevated temperatures. This was not observed in acetylsalicylic acid-treated rabbits.
Hypotensive effects and biotransformation of nicorandil, a new antianginal agent, administered to rats by different routes: comparison with nitroglycerin and isosorbide dinitrate
Authors: Sakai Kazushige , Akima Michitaka , Hinohara Yoshikazu , Obatake Noriko 
Published: April 2011

Abstract
The effects of nicorandil, N-(2-hydroxyethyl)nicotinamide nitrate (ester), in reducing systemic blood pressure (SBP) in rats were studied in comparison with isosorbide dinitrate and nitroglycerin. The drugs were administered to pentobarbitone-anaesthetized rats by jugular vein (i.v.), portal vein (p.v.), intrajejunal (i.j.), intraperitoneal (i.p.) and subcutaneous (s.c.) routes. Nicorandil was absorbed rapidly through all routes, and caused marked hypotension dose-dependently. With isosorbide dinitrate and nitroglycerin, unlike nicorandil, the p.v. dose required to induce a vasodepressor response was significantly greater than that required to cause a comparable response after i.v. administration. In non-recirculating rat liver perfusion experiments, nicorandil was reduced only 5–10% during a single passage through the liver, while nitroglycerin was reduced over 95%. In recirculating liver perfusion experiments, the progressive decrease of nicorandil in the blood recirculated was accompanied by a corresponding increase of SG-86, a denitrate compound of nicorandil (its main metabolite). Sixty min after dosing, nicorandil was decreased by approximately 73% of the initial nicorandil blood concentration and SG-86 was increased by approximately 70%. The extent of degradation of nicorandil in liver homogenates, examined by thin-layer chromatography, was in the following order: rat = guinea-pig &gt; dog = monkey &gt; pig. In these species a close inverse relationship is apparent between the rate of liver nicorandil degradation and hypotensive effects of nicorandil.
Quinidine-induced rise in ajmaline plasma concentration
Authors: Hori Ryohei , Okumura Katsuhiko , Inui Ken-Ichi , Yasuhara Masato , Yamada Kazushi , Sakurai Tsunetaro , Kawai Chuichi 
Published: April 2011

Abstract
A high-performance liquid chromatographic method is described for the simultaneous determination of ajmaline and quinidine in human plasma. With 0·5 ml plasma samples of ajmaline and quinidine, concentrations as low as 0·001 and 0·01 μg ml−1, respectively, could be detected and the technique could be used to investigate the effect of quinidine on the pharmacokinetics of ajmaline. Four healthy subjects were given oral ajmaline (50 mg) alone or in combination with quinidine sulphate (200 mg) on separate occasions. When ajmaline was administered alone, its plasma concentrations were less than 0·03 μg ml−1. Quinidine induced a marked increase to give a mean peak concentration of ajmaline which increased from 0·018 μg ml−1 after a single administration to 0·141 μg ml−1 in combination with quinidine. The area under the ajmaline concentration-time curves was increased 10 to 30-fold by the concurrent administration of quinidine. According to the one compartment open model, the absorption rate constant of ajmaline did not change appreciably, but the elimination rate constant was reduced to approximately 50% of the value in the absence of quinidine. The results indicate the existence of a significant interaction between oral ajmaline and quinidine.