bluuebunny/crossref_metadata_2025_split huggingface dataset:
Temperature changes occurring during the compression and recompression of solids
Authors: Travers D N , Merriman M P H 
Published: April 2011

Abstract
Measurements of the temperature rise occuring on compression, recompression and relaxation of compacts formed from Asagran, sodium chloride and boric acid have been made by means of thermocouples inserted into the compressed materials. There are marked differences in temperature rise for the different compacts when compressed to a final force of 50 kN (5 tons). With all compacts there was a rise in temperature on initial compression and a fall in temperature on relaxation. The rise could be separated into two components—that due to compact formation plus a further rise due to its elastic compression. The fall in temperature is thought to result on release of the strain energy stored in the compact. The rise in temperature on recompression followed by the fall of relaxation could be repeated many times on the same compact. Both rise and fall were directly proportional to the final compression force used. The fall on relaxation appeared to be numerically less than the rise on recompression for compacts of boric acid and Asagran. Lubrication of Asagran with magnesium stearate had little effect on the temperature rises.
The effect of particle shape on the variation of fill of a tabletting die
Authors: Ridgway K , Scotton Janet B 
Published: April 2011

Abstract
A 12 mm die cavity has been repeatedly filled from batches of granular material of a range of particle shape and size distributions. The variance in the weight contained by the die was determined from the replicates. The variance, expressed as a coefficient of variation to allow for differences in the means of groups of replicates, increased from 0·2635 to 0·7222 as the particle shape, expressed as the Heywood shape coefficient, increased in irregularity from a value of 8 to 13. The mean contained weight was greater for regular than for irregular particles, and a maximum die fill occurred where the ratio of die diameter to particle diameter was about 20 for all particle shapes.
The surface hardness of tablets
Authors: Ridgway K , Aulton M E , Rosser P H 
Published: April 2011

Abstract
A pneumatic micro-indentation apparatus has been used to determine the hardness of tablets of aspirin at various points on their diameter. All the tablets were 13 mm diameter; the compaction pressure and the particle size of the initial material were varied. The compression was carried out in a Perspex die so that radial pressure could also be assessed during compaction. The micro-indentation apparatus measured the total deformation at the loaded point on the tablet, and also the elastic recovery when the load was removed.
The influence of wet and dry granulation methods on the pore structure of lactose tablets
Authors: Selkirk Alastair B , Ganderton David 
Published: April 2011

Abstract
The conditions of wet granulation influenced the pore structure of lactose tablets, prepared over a wide range of tabletting pressures. Dry granulation, on the other hand, only influenced pore structure when slugging pressures were high, the granules were coarse and tabletting pressures were low. Mercury porosimetry revealed intense granule fragmentation when dry granulated materials were compressed. The effect of the change of pore size distribution on liquid penetration into tablets is discussed.
The effect of temperature on the solubilities of testosterone propionate in low polarity solvents
Authors: Bowen D B , James K C 
Published: April 2011

Abstract
The solubilities of testosterone propionate have been determined between 25 and 100° in 15 solvents and compared with theoretical values obtained from regular solution theory. Entropy considerations show that solvent-solute interactions occur in some solvents, increasing the solubility and resulting in deviations from regular solution behaviour. “Regular solutions” are obtained only in saturated hydrocarbon solvents, and the solubility is more accurately predicted as the temperature approaches the melting point, and as the molar volumes of solvent approach that of the solute.
Nuclear magnetic resonance studies on micelle formation by promethazine hydrochloride
Authors: Florence A T , Parfitt R T 
Published: April 2011

Abstract
The pmr spectra of solutions of promethazine hydrochloride in D2O have been obtained as a function of concentration above and below the critical micellar concentration of the drug. Chemical shifts were obtained relative to an external standard of a 20% promethazine solution (micellar). The shifts of the spectrum of the hydrophilic NH(CH3)2 group to higher fields on increasing concentration were explained by the increased dissociation of the group at the micelle surface, an effect illustrated by the decrease in bulk pH at the critical micelle concentration. Diamagnetic shifts of the aromatic ring protons are compatible with the non-polar environment and a parallel stacking of the phenothiazine rings in the interior of the micelle.
The correlation of unsteady-state heat transfer data from a sterilizing oven
Authors: Peacock D G , Ridgway K 
Published: April 2011

Abstract
Data, showing the pattern of temperature rise in articles undergoing sterilization in an oven under normal working conditions, have been studied. Simple mathematical models, each expressed in terms of a set of differential equations rather than in an explicit analytical form, have been fitted to these data, and the quality of fit and possible applications are here discussed.
Grade variation in the rheology of white soft paraffin B.P.
Authors: Barry B W , Grace A J 
Published: April 2011

Abstract
The rheology of six grades of white soft paraffin B.P. at 25° has been investigated using continuous shear viscometry and a creep viscometer. Temperature effects between 25° and 50° have been measured in continuous shear, and activation energies from 14·0 to 25·3 k cal mol−1 (58·6 to 105·9 k J mol−1) have been determined. Working the samples on a triple roller mill at 25° was found to decrease the apparent viscosity and, initially, to increase the yield stress. Five of the grades were linear viscoelastic, one was non-linear viscoelastic. The nature of ductility and its relation to measured rheological parameters have been discussed. Creep viscometry data gave a better correlation with the manufacturer’s data than did continuous shear measurements.
Application of the Ferguson principle to the antibacterial activity of mono- and multi-component solutions of quaternary ammonium surface-active agents
Authors: Laycock H H , Mulley B A 
Published: April 2011

Abstract
Critical micelle concentrations (cmc) have been measured by the surface tension method for binary mixtures of dodecyltrimethyl-ammonium bromide with tetradecyltrimethylammonium bromide, binary mixtures of C14/C16 homologues, a ternary mixture of the C12/C14/C16 compounds and additionally for each component individually. The antibacterial activities of the systems against Escherichia coli were determined by a British Standard Method (B.S. 3286: 1960). Thermodynamic activities of the solutions at two survivor levels, calculated from the physical and biological measurements, were sufficiently constant to sustain the Ferguson principle for these micelle-forming antibacterial agents. A theoretical treatment of micelle formation for multi-component solutions of surfactants gave cmc’s by calculation in close agreement with the experimentally determined values. The purity and composition of the surfactants was determined by gas liquid chromatography.
The effect of directly and indirectly acting sympathomimetic amines on bronchospasm in the guinea-pig during CO2 inhalation
Authors: Atkinson Judith M , Pun Lan-Queen , Rand M J 
Published: April 2011

Abstract
The bronchodilator effects of nine sympathomimetic amines were tested by reduction of histamine-induced bronchospasm in guinea-pigs. Their order of potency was: isoprenaline &gt; adrenaline &gt; noradrenaline &gt; orciprenaline &gt; ethylnoradrenaline &gt; phenylephrine &gt; amphetamine = tyramine &gt; ephedrine. In guinea-pigs ventilated with 10% CO2 in air, there was a marked decrease in the bronchoconstrictor activity of histamine. Under these conditions, isoprenaline, adrenaline, noradrenaline and orciprenaline were as effective as bronchodilators as they had been in guinea-pigs ventilated with air, ethylnoradrenaline was less effective, phenylephrine, amphetamine and tyramine were completely inactive, and ephedrine potentiated the bronchoconstrictor action of histamine. After returning the guinea-pigs to ventilation with air, the bronchoconstrictor activity of histamine and the bronchodilator effects of the sympathomimetic amines were restored. The cardiovascular effects of histamine and of all the sympathomimetic amines used were diminished during ventilation with 10% CO2 in air and were restored after ventilation with air was resumed.
Selective determinations of amines and quaternary ammonium compounds as ion pairs with methyl orange by an automated method applicable to single dose analysis
Authors: Nyberg Lars 
Published: April 2011

Abstract
Aliphatic amines and quaternary ammonium compounds can be determined photometrically after extraction as ion pairs with methyl orange. Extraction conditions are calculated from constants for the extraction procedure and side-reactions. Methods for the selective determination of ammonium ions of different degrees of substitution are given. Quaternary ammonium ions are isolated by extraction at pH 12. The amines are extracted as ion pairs at pH 4.6 and selective determinations can be made after primary and secondary amines are masked by acetylation and primary amines by coupling with salicylic aldehyde. An automated application of the method on a Technicon AutoAnalyzer is presented. A complete analysis of a sample containing the four kinds of ammonium ions requires four separate runnings. The same basic manifold is used for all the runnings with some rearrangements for the masking procedures. The method has been tested on benzhexol, diethylpropion, dodecylamine, emepronium, N-hydroxyethylpromethazine, promethazine and protriptyline. Recoveries of about 100% with a relative variation of 1–2% were obtained.
Determination of piribenzil in urine containing a metabolite and dextropropoxyphene by an ion pair extraction method
Authors: Borg K O , Holgersson H , Lagerström P O 
Published: April 2011

Abstract
Piribenzil, an antispasmodic quaternary ammonium compound, has been determined quantitatively in human urine containing a metabolite of piribenzil and dextropropoxyphene. Ion pair extraction with bromothymol blue as counter ion was used and the extraction conditions were calculated from extraction constants and partition coefficients determined using methylene chloride as organic solvent. The determination was made by photometry in the range 5–50 μg of piribenzil methyl sulphate/ml of urine. The recovery was 97% ± 3%. The co-extraction of urine components such as nicotine, tyramine, tryptamine and choline was investigated by determination of constants for the partition of these compounds.
An investigation of the distribution coefficients of some androgen esters using paper chromatography
Authors: Bowen D B , James K C , Roberts Margaret 
Published: April 2011

Abstract
Rm values have been determined for four homologous series of androgen esters, using a Bush paper chromatography system, to assess the value of the ratio of the solubilities in the individual solvents (solubility ratio), as an estimate of distribution coefficient. The distribution coefficients were proportional to Rm values in all four series, and for three of these the proportionality constant was the same. Limitations in the use of RM values to predict biological effects have been pointed out.
Central hypotensive effect of L-3,4-dihydroxyphenylalanine in the rat
Authors: Henning M , Rubenson A 
Published: April 2011

Abstract
Mean arterial blood pressure was recorded through in-dwelling arterial catheters in conscious normotensive Sprague-Dawley rats. L-3,4-Dihydroxyphenylalanine (L-dopa) was given in various doses intraperitoneally, alone and after pretreatment with an inhibitor of dopa decarboxylase, α-hydrazino-α-methyl-β-(3,4-dihydroxyphenyl) propionic acid (MK 485) or seryl-2,3,4-trihydroxybenzylhydrazine (Ro 4–4602). L-Dopa (50 mg/kg) produced a hypertensive response which was abolished by MK 485 (100 mg/kg). A larger dose of L-dopa (200 mg/kg) after MK 485 caused a significant lowering of blood pressure after 15–20 min. After Ro 4–4602 (400 + 200 mg/kg), injection of L-dopa (200 mg/kg) had no significant effect on blood pressure. The hypotensive response to L-dopa (200 mg/kg) after MK 485 was not influenced by the central dopamine receptor blocking agent, spiroperidol (0.1 mg/kg), but could be completely inhibited by the dopamine β-hydroxylase inhibitor, bis-(4-methyl-1-homopiperazinyl-thiocarbonyl)disulphide (FLA 63) (40 mg/kg). Pretreatment with protripty-line (10 mg/kg) completely blocked the hypotensive effect of L-dopa after MK 485. In correlative biochemical experiments, levels of noradrenaline and dopamine were determined in brain, heart and femoral muscle. L-Dopa (200 mg/kg) alone caused a significant increase of dopamine levels in all tissues. After MK 485 and Ro 4–4602 L-dopa did not significantly increase the levels of dopamine in heart or femoral muscle; however, brain dopamine levels were increased more than after L-dopa alone, but brain dopamine levels after Ro 4–4602 were significantly lower than after MK 485, indicating some central decarboxylase inhibition by Ro 4–4602. L-Dopa alone reduced the noradrenaline content of the heart and this effect was prevented by MK 485 and Ro 4–4602. The results show that decarboxylation of L-dopa in both the central and the peripheral nervous system leads to an increase in blood pressure. Decarboxylation of L-dopa in the central nervous system only results in a hypotensive response, provided that high amounts of dopamine are formed in the brain. This effect was prevented by an inhibitor of dopamine β-hydroxylase but not by a dopamine receptor blocker. Therefore, a central noradrenaline mechanism seems to be involved. The presence of an intact membrane pump in noradrenaline neurons may be essential since protriptyline also blocked the hypotensive action.
The effects of calcium on adrenergic neuron blockade
Authors: Wilson J 
Published: April 2011

Abstract
The effects of increasing extracellular calcium were investigated on the responses to sympathetic nerve stimulation of three isolated organs; rabbit ileum, guinea-pig vas deferens and rabbit ear artery. A rise in the calcium concentration increased the responses of the ileum to low frequency stimulation, the maximum increase being obtained at 8.8 mM calcium. After partial blockade by guanethidine of the responses of the ileum to high frequency stimulation, raised calcium concentrations again increased the responses. The increase was similar in guanethidine-treated and untreated preparations and the maximum increase in both was obtained using 8.8 mM calcium. In the vas deferens and rabbit ear artery preparations an increase in extracellular calcium did not antagonize the blocking action of guanethidine. These experiments do not therefore support the theory that guanethidine acts by preventing the entry of calcium into the sympathetic nerve endings.
The effect of sodium salicylate on the release of acid phosphatase activity from rat liver lysosomes in vitro
Authors: Harford Deborah J , Smith M J H 
Published: April 2011

Abstract
Salicylate, in concentrations up to 10mM, does not inhibit the activity of the acid phosphatase liberated from rat liver lysosomes. The release of the enzyme from lysosomal preparations incubated with the drug depends on the pH of the incubation medium, the duration of incubation and the concentration of salicylate. It is concluded that salicylate does not influence lysosomal stability in vivo.
The relative purgative activities of 1,8-dihydroxyanthracene derivatives
Authors: Fairbairn J W , Moss M J R 
Published: April 2011

Abstract
The purgative activities of twelve different 1,8-dihydroxyanthracene derivatives including free anthraquinone, anthrone and dianthrone forms, anthraquinone O-glycosides and dianthrone O-glycosides were compared with senna pod powder using the production of wet faeces by mice as a criterion of purgation. The higher purgative activity of the dianthrone glycosides was confirmed for the compounds based on rhein. Sennidin (rhein dianthrone) was more active than had previously been reported. These highly active compounds had parallel dose response curves which were not parallel to those of the less active rhein anthrone, rhein, aloe-emodin and chrysophanol. Emodin and chrysazin were inactive in mice. The highly active compounds exerted a high activity during the initial 3 h after dosage while the less active compounds were virtually inactive during this period. Rhein anthrone appeared to act initially like the highly active primary sennosides, sennoside A and sennidin and later as the less active rhein. The results are discussed in relation to the mode of action of orally administered 1,8-dihydroxyanthracene derivatives.
A stability study of chloramphenicol in topical formulations
Authors: James K C , Leach R H 
Published: April 2011

Abstract
The stabilities of several chloramphenicol preparations have been investigated at ambient temperatures. The B.P.C ointment and eye ointment were stable over 2 years. The remainder retained more than 90% of their potencies after the following periods: ear drops B.P.C., 2 years, Drug Tariff cream, 5 months and eye drops B.P.C., 3 to 4 months. 15% hydrolysis occurred after autoclaving the eye drops, and 3 to 4% after heating with a bactericide. The latter sterilization process is recommended. Two assay procedures were employed, one estimating residual chloramphenicol by ultraviolet spectrophotometry after separation from decomposition products by thin layer chromatography and the other determining the main degradation product (1-p-nitrophenylpropan-1,3-diol-2-amine) colorimetrically.
Flow properties of aluminium soap-hydrocarbon systems
Authors: STEPHENS J S 
Published: April 2011

Abstract
Organogels prepared from aluminium stearate and liquid paraffin in concentrations of 0·5 to 17·0% by weight were examined using a rotational viscometer fitted with cone and plate. Parameters used to characterize the flow curves of these gels were plastic viscosity, apparent viscosity at fixed rates of shear and the estimated area of the hysteresis loop. The influence of temperature and aluminium stearate concentration on the shapes of the curves was examined. Concentration of aluminium stearate and temperature were found to influence both thixotropic behaviour and the rate of recovery after shear. A minimum concentration of 1·5 to 2·0% by weight of aluminium stearate appeared to be necessary for the formation of the gel structure.
Nuclear magnetic resonance studies of interactions between cetomacrogol and phenol
Authors: JACOBS J J , ANDERSON R A , WATSON T R 
Published: April 2011

Abstract
Phenol solubilized in cetomacrogol micelles appears to accumulate principally in the polyoxyethylene region and appears not to be randomly distributed along the polyoxyethylene chains. When concentrations of phenol are sufficiently high, a phenol-cetomacrogol-rich phase separates. This phase contains relatively little water and the phenol molecules may be randomly distributed along the polyoxyethylene chains. Transfer of molecules between the phases of these cloudy systems is relatively slow.
Differences in the stereospecificity of closely related compounds; a reinvestigation of the enantiomers of procyclidine, benzhexol and their metho- and etho-salts
Authors: BARLOW R B 
Published: April 2011

Abstract
The findings of Duffin & Green (1955) that there are very large differences in the stereospecificity of some closely related phenyl-cyclohexylhydroxypropyl compounds have been confirmed, and it has been shown that this cannot be ascribed to any errors attached to the methods for assessing biological activity, or to inadequate resolution of some of the compounds. Measurement of the affinity constants of the compounds for the postganglionic acetylcholine receptors of the guinea-pig ileum showed that the (+)-and (-)-isomers of benzhexol differ only 5·5-fold in affinity whereas the (+)-and (-)-isomers of procyclidine differ at least 375-fold. This big variation in stereospecificity indicates that changes in one part of the molecule markedly affect the binding of the rest of the molecule and the effects are different in the different enantiomers. It is not possible to interpret the difference between the affinity of the isomers simply in terms of the fit, or failure to fit, of one group, such as the hydroxyl, attached to the asymmetric centre. In the five pairs of compounds tested, the stereospecificity was greatest in the compounds with lowest affinity, which is the reverse of what would be predicted from Pfeiffer's rule.
The action of isoprenaline on the perfused vessels of the rabbit ear
Authors: DAY M D , DIXON HAZEL V R 
Published: April 2011

Abstract
In rabbit isolated perfused ear preparations isoprenaline in doses of 1 to 5 μg caused a vasodilatation which was specifically blocked by propranolol. In a minority of experiments larger doses of isoprenaline (5 to 10 μg) caused vasoconstriction. The vasodilatations to isoprenaline were increased by raising vascular tone with barium chloride whereas ergotamine and sympathetic stimulation were relatively ineffective. In the isolated ear central artery preparation, isoprenaline caused a vasoconstriction due to α-receptor stimulation. A vasodilator response due to β-receptor stimulation was revealed when perfusion pressure was raised with barium chloride. It is concluded that α- and β-adrenergic receptors are present in both preparations but a higher proportion of β-receptors are present in the whole ear.
The selective uptake of mercury by myocardial infarcts in the rat
Authors: LESZKOVSZKY G P , SZÁNTHÓ VILMA 
Published: April 2011

Abstract
Rats with myocardial infarcts, sham operated and control animals were treated with methoxyethyl mercury chloride (MEMC) intra-peritoneally or with mercamphamide intravenously or intra-peritoneally and the mercury content in the hearts determined spectrophotometrically with dithizone after various time intervals. After MEMC treatment there was no difference between the amounts of mercury found in the hearts of rats with myocardial infarcts and controls. After injection of mercamphamide, mercury was taken up by hearts of rats with myocardial infarcts while those of sham operated and control animals remained free of mercury. Optimal results were yielded by 1 h experiments made within the first 24 postoperative hours. The selective uptake of mercury from organo-mercurials is much dependent on the organic part of the molecule present in the given individual compound.
Non-competitive spasmolytics as antagonists of Ca++-induced smooth muscle contraction
Authors: SIMONIS A M , ARIËNS E J , VAN DEN BROEKE J J W 
Published: April 2011

Abstract
The spasmolytic drugs papaverine, phenpropamine, Cxn 2 (1-methyl-amino-3,3,5-trimethylcyclohexane), khellin, cyclandelate, magnesium chloride, cocaine, 2,4-dinitrophenol and KCN antagonize various types of spasmogens, such as acetylcholine or histamine, non-competitively. They are assumed to act at some level in the excitation-contraction process common to the various spasmogens. Ca++ is essential for the induction of a contraction by the spasmogens. In the non-competitive action of some spasmolytics, Ca++ is postulated to be involved. To detect possible differences in their mechanism of action the various spasmolytics were tested against Ca++ acting as a pseudo-spasmogen on the K+-primed taenia caeci of the guineapig in a Ca++-free medium. Although different mechanisms of action for the various spasmolytics are to be expected, they all behaved similarly with respect to Ca++ in that they all caused a parallel shift in the log dose-response curve of Ca++ to higher concentrations.