bluuebunny/crossref_metadata_2025_split huggingface dataset:
Uniformity of content requirements for tablets and capsules
Authors: KENDALL C E , LOW G K-C , HAILEY D M 
Published: April 2011

Abstract
Present pharmacopoeial requirements for uniformity of content of tablets and capsules are based on tests by attributes. A test for uniformity of content based on the root mean square deviation about target (ST) is more reliable than the pharmacopoeial tests and has the added convenience of using a single statistic to control both the mean content and the variation about the mean. Implications of the use of the statistic ST in uniformity requirements are discussed.
Analysis of moisture sorption hysteresis in hard gelatin capsules, maize starch, and maize starch: drug powder mixtures
Authors: YORK PETER 
Published: April 2011

Abstract
Moisture sorption and desorption isotherms at 25°C for hard gelatin capsules, maize starch and 50:50 mixes of maize starch: barbitone and maize starch: sodium barbitone have been measured. The sorption hysteresis observed in all four systems studied has been analysed according to the hypothesis of Young & Nelson (1967a) which distinguishes three locations for moisture—monolayer adsorbed moisture, normally condensed moisture and absorbed moisture. Hysteresis is explained by a separation of absorption and desorption isotherms for absorbed moisture and different patterns of moisture distribution are demonstrated in the four systems examined.
The stability of trifluorothymidine: hydrolysis in buffered aqueous solutions
Authors: JONES M F 
Published: April 2011

Abstract
The decomposition of trifluorothymidine in aqueous solution, and borate and phosphate buffers has been studied using an h.p.l.c. method. In aqueous solution accelerated studies demonstrate that a storage life, to 10% loss, of more than 30 years at 4°C is predicted, but steam sterilization causes extensive breakdown. Considerable differences occur in the kinetics and routes of decomposition in borate and phosphate buffers in the pH range 4–8. Hydroxide ion attack producing 5-carboxy-2′-deoxyuridine is suppressed in borate buffers. Complex kinetics of decomposition in phosphate buffer are found and possible explanations suggested. Steam sterilization in buffered solution also leads to unacceptable breakdown.
Apparent diffusion coefficient of sodium phenobarbitone in ethylcellulose microcapsules: effects of capsule size
Authors: SENJKOVIČ R , JALŠENJAK I 
Published: April 2011

Abstract
Ethylcellulose microcapsules of sodium phenobarbitone with a thick wall were prepared and fractionated. The apparent diffusion coefficient of sodium phenobarbitone was measured for the transport of the drug from the core of microcapsules into the surrounding sink condition. The apparent diffusion coefficient decreased with decreasing capsule size. Apart from structured water in and around the capsule wall, the volume fraction of pores in the membrane has been suggested as the source of the observed trend.
Fluorescence spectroscopic analysis of the hydrogen bonding properties of catecholamines, resorcinolamines, and related compounds with phosphate and other anionic species in aqueous solution
Authors: DE VENTE J , BRUYN P J M , ZAAGSMA J 
Published: April 2011

Abstract
Fluorescence spectroscopic analysis based upon the difference in fluorescent behaviour of several phenol, catechol and resorcinol derivatives in 0·2 M phosphate and water, at different pH values ranging from 7·4 to 1·0, produced evidence for the existence of complexes between phosphate anions and these compounds. This complex formation was also found with acetate, citrate and glutamate but not with sulphate and borate. A comparison of different ligand structures revealed that the complex formation observed with unsubstituted phenol, catechol or resorcinol was not influenced by ethyl substitution; however, ethylamine or ethanolamine substitution favoured the formation of the complex. The findings indicate the formation of 1:1 intermolecular complexes between mono- and dihydroxyphenethylamines and several anionic species with participation of two hydrogen bonds. The predictions of a theoretical model describing this interaction are confirmed by the experimental data. Association constants of isoprenaline with phosphate and glutamate were found to be 5·1 and 26·6 litres mol−1 respectively; for the complexes of m-tyramine and terbutaline with phosphate, association constants of 15·3 and 6·9 litres mol−1 respectively, were obtained.
The metabolism of bifluranol by rat, dog and ferret
Authors: POPE D J , GILBERT A P , EASTER D J , CHAN R P , TURNER J C , GOTTFRIED S , PARKE D V 
Published: April 2011

Abstract
The synthesis of monohydroxy- and dihydroxy-bifluranol, and of glucuronide and sulphate conjugates of bifluranol are described. Bifluranol administered orally to rats, ferrets and dogs at a dosage of 50 to 200 μg kg−1 is mostly excreted in the faeces as unchanged bifluranol and bifluranol monosulphate, disulphate and monoglucuronide. The bifluranol is well absorbed and is mostly excreted in the bile, as six different conjugates, including a glucuronide sulphate found in all 3 species, and a glucuronide phosphate found only in ferret and dog bile. Hydroxylation of the aromatic rings occurs in the rat, to an extent of about 8% of the dose, but was not detected in ferret or dog.
Synthesis of N-oxide derivatives of metyrapone and their detection as in vitro metabolites
Authors: CROOKS PETER A , DAMANI LYAQUATALI A , COWAN DAVID A 
Published: April 2011

Abstract
A variety of possible N-oxidation products of 2-methyl-1, 2-bis(3-pyridyl)propan-1-one (metyrapone) have been synthesized by peracid oxidation, and characterized using various spectroscopic techniques. Specific and sensitive chromatographic techniques have been developed for the separation and identification of its in vitro metabolites. Incubation of metyrapone with rat or mouse hepatic microsomes, in the presence of a NADPH-regenerating system, leads to the formation of metyrapol (keto-reduction), and two mono-N-oxides.
β1-Adrenoceptors mediating relaxation of the guinea-pig trachea: experiments with prenalterol, a β1-selective adrenoceptor agonist
Authors: JOHANSSON ULF , WALDECK BERTIL 
Published: April 2011

Abstract
In the presence of 17 β-oestradiol, prenalterol, a β1-selective adrenoceptor agonist, caused a dose-dependent relaxation of the isolated, pilocarpine-contracted guinea-pig trachea. This effect was blocked by the antagonists propranolol (non-selective) and practolol (β1-selective) but not by IPS 339 [(t-butylamino-3-ol-2-propyl)oximino-9-fluorene HCl] (β2-selective). The relaxing effect of terbutaline, a β2-selective adrenoceptor agonist, was more efficiently blocked by IPS 339 than by practolol. These data support the hypothesis that the guinea-pig trachea contains both β1- and β2-adrenoceptors mediating relaxation and that the β1-adrenoceptors are selectively stimulated by prenalterol. The efficacy of prenalterol was less than that of terbutaline, thus confirming its partial agonistic activity. In the absence of 17 β-oestradiol, the ability of prenalterol to relax the pilocarpine-contracted trachea was lost. It is suggested that 17 β-oestradiol may act as a functional antagonist to pilocarpine as it caused a partial relaxation itself.
Interference of pentobarbitone with the contraction of vascular smooth muscle in goat middle cerebral artery
Authors: MARÍN JESUS , RICO MERCEDES L , SALAICES MERCEDES 
Published: April 2011

Abstract
Pentobarbitone (10−5 to 10−3 M) decreased the basal tone of vascular smooth muscle of goat middle cerebral artery in a dose-dependent manner as well as relaxing established contractions induced by noradrenaline (NA) (10−5 M), 5-hydroxytryptamine (5-HT) (10−5 M) and KCl(120 mM). Preincubations with pentobarbitone reduced the contractions evoked by these three agents in a dose-dependent way. It also decreased Ca2+-induced contractile responses in K+-depolarized arteries and 5-HT-Ca2+ and NA-Ca2+ contractions dose-dependently. Contractions induced by K+ were more sensitive to the depressant actions of the drug than those produced by NA and 5-HT. The small contractions evoked by K+ and 5-HT in Ca2+-free medium were also reduced in its presence. The antagonism Ca2+-pentobarbitone was insurmountable. These results suggest that the drug interferes with Ca2+ entry and Ca2+ release from cell stores, and therefore with the smooth muscle contractions.
The tetrahydrocannabinol and tetrahydrocannabinolic acid content of cannabis products
Authors: BAKER P B , TAYLOR B J , GOUGH T A 
Published: April 2011

Abstract
Cannabinoid acids readily decarboxylate to the corresponding cannabinoid. Methods are available for the determination of Δ9-tetrahydrocannabinol (THC) and its acids (THCA) and published data on the levels of these compounds in cannabis are summarized. Using gas and liquid chromatography, fresh cannabis (64 samples) and cannabis resin (26 samples) from different countries were examined. Wide variations in the relative amounts of THCA and THC in cannabis were found. For cannabis resin, a wide range of values was also found (0·5: 1 to 6·1: 1), the lower values being in resins from the Indian sub-continent and the higher values in resins from the Mediterranean area. Total THC values were in the range 1·–10·6% in cannabis and 6·0–12·5% in cannabis resin.
Effect of dyes on the photodecomposition of pyridoxine and pyridoxamine
Authors: MIZUNO NOBUYASU , FUJIWARA ASAMI , MORITA EMIKO 
Published: April 2011

Abstract
Erythrosine, eosine Y, rose bengal, mercurochrome, methylene blue, azure A and azure B accelerated the photodecomposition of pyridoxine and pyridoxamine at pH 5–9, but fluorescein and acid red did not. The photodecomposition of pyridoxine in the presence of erythrosine was greatest at pH 9·0, The singlet oxygen generated by light-excited dyes played a role as a mediator in the decomposition of pyridoxine but the degradation products of erythrosine had no effect. The photodecomposition of pyridoxine and pyridoxamine in the presence of dyes was depressed by aminopyrine, sulpyrine and tryptophan. Pyridoxine 3, 4′-dioctanoate was stable in the presence of erythrosine.
Effect of temperature changes on the densification and compression of griseofulvin and sucrose powders
Authors: ONYEKWELI A O , PILPEL N 
Published: April 2011

Abstract
A study has been made of the effect of varying the temperature between +60° and −25°C on the densification and low pressure compression of griseofulvin, sucrose and mixtures of the two powders. Densification and compression of the materials were facilitated as they were cooled in the range of homologous temperatures (ratio of the experimental temperature in°K to melting point of the material in°K) from 0·7 to 0·5. This was attributed to a reduction in the cohesive forces operating between the particles. Values are given for the activation energies of densification and compression derived by plotting the logarithms of these properties versus the reciprocal of the absolute temperature. For both materials and their mixtures the activation energies were in the range of about 1 to 10 kJ mol−1 showing that physical rather than chemical forces were operating between the particles.
The prolongation of the in vitro dissolution of a soluble drug (phenethicillin potassium) by microencapsulation with ethyl cellulose
Authors: ALPAR H OYA , WALTERS V 
Published: April 2011

Abstract
Microcapsules of phenethicillin potassium as a model water-soluble drug, coated with ethyl cellulose, have been prepared (core: wall ratios 1:1, 1:2 and 1:3) in which the taste has been masked, the odour almost eliminated and the release retarded. Sieve analysis showed that with decreasing core: wall ratios there was a trend towards increasing amounts of larger sized microcapsules. At constant core: wall ratios in vitro release of drug was generally greatest from the larger microcapsules. This result correlated with the surface areas of the microcapsules which became less as the asymmetry of the microcapsules diminished with decrease in microcapsule size. There was a linear relation between the amount of ethyl cellulose and the time for 60% release of drug, and the release pattern was analogous to that from insoluble porous matrices. Scanning electron micrographs showed the microcapsules to be irregularly shaped with circular surface pores, and they did not alter in shape or size during dissolution. Tableting of 1:1 core: wall ratio microcapsules significantly further retarded the dissolution.
The in vivo metabolism of Althesin (alphaxalone + alphadolone acetate) in man
Authors: HOLLY J M P , TRAFFORD D J H , SEAR J W , MAKIN H L J 
Published: April 2011

Abstract
Gas chromatography-mass spectrometry has been used to study the metabolism of Althesin (alphaxalone and alphadolone acetate) in man. Two metabolites, 20α-reduced alphaxalone and alphadolone, as well as the two parent steroids, have been detected in the plasma during and after an infusion of Althesin. The main urinary metabolites were alphaxalone and 20α-reduced alphaxalone, with smaller amounts of alphadolone, all of which were excreted mainly as the glucuronide conjugates. No alphadolone acetate was detected in the urine. In 3 patients in whom bile was collected over the 1st 24 h post-operation from an indwelling T-tube, it has not been possible using the methods described to detect in bile the presence of the parent steroids, or any of their probable metabolites.
The influence of initial packing on the compression of powders
Authors: SHEIKH-SALEM M , FELL J T 
Published: April 2011

Abstract
The influence of the initial packing density on the compression properties of lactose and sodium chloride has been studied. Differences in initial packing density are eliminated for both materials at relatively low pressures. The results have been analysed by the equations of Kawakita (1956), Heckel (1961), and Cooper & Eaton (1962). The constants derived from the Cooper & Eaton equation are dependent on the choice of low pressure data. The Kawakita constants are influenced by the initial packing of the powder. The Heckel treatment uses data at pressures above the point where the initial packing exerts an influence. Hence the constants are independent of the initial packing. If comparisons are to be made between processing treatments or mixtures which change the initial packing of the powder, the Heckel equation would appear to offer the most valid approach.
The systemic bioavailability of buprenorphine by various routes of administration
Authors: BREWSTER DAVID , HUMPHREY MICHAEL J , MCLEAVY MICHAEL A 
Published: April 2011

Abstract
The systemic bioavailability of buprenorphine has been studied in female rats following single doses (200 μg kg−1) administered by one of six different routes. Relative to the 100% bioavailability from the intraarterial route the mean bioavailabilities were intravenous, 98%; intrarectal, 54%; intrahepatoportal, 49%; sublingual, 13%; and intraduodenal, 9·7%. Area under the curve analysis of buprenorphine concentrations in blood showed the relative fractions of drug extracted (first pass) by gut, liver and lung to be 0·80, 0·50 and 0·02 respectively, In situ absorption studies showed that the poor availability of intraduodenally administered buprenorphine is not due to slow or incomplete absorption.
A pre-junctional action of 5-hydroxytryptamine and methysergide on noradrenergic nerves in dog isolated saphenous vein
Authors: WATTS A D , FENIUK W , HUMPHREY P P A 
Published: April 2011

Abstract
Electrical stimulation (2 Hz for 2 min) of dog isolated saphenous vein strips pre-incubated with tritiated noradrenaline increased the overflow of tritium of which about 80% was noradrenaline. 5-Hydroxytryptamine (5-HT; 1·0 × 10−9-1·0 × 10−7 mol litre−1) and methysergide (3·0 × 10−8-3·0 × 10−8 mol litre−1) inhibited the induced overflow of total tritium by a maximum of 78 ± 4% and 47 ± 7% respectively (mean ± s.e. mean, n = 6 for each). Methysergide was about 30 times less potent than 5-HT and the maximum inhibition obtained was less than with 5-HT. Both compounds inhibited electrically-induced contractions and overflow of tritiated noradrenaline. Their inhibitory actions on tritium overflow were little affected by phentolamine (1·0 × 10−8 mol litre−1) or cyproheptadine (1·0 × 10−8 mol litre−1), nor was the inhibitory effect of methysergide on electrically induced contractions antagonized by atropine, mepyramine, cimetidine or propranolol. The findings suggest that the prejunctional inhibitory effect of methysergide may be mediated via stimulation of a 5-HT receptor which, unlike the D-receptor, is not blocked by cyproheptadine. The possibility that the pre-junctional 5-HT receptor in the dog saphenous vein is the same as the post-junctional receptor in this preparation is discussed.
Amine oxidase in human blood vessels and non-vascular smooth muscle
Authors: LEWINSOHN RACHEL 
Published: April 2011

Abstract
The pattern of amine oxidation was studied in human blood vessels at various stages of development, and in tissues with muscular layers made up predominantly or exclusively of smooth muscle. Specific activity of benzylamine oxidase, present in all vascular tissues examined, was higher in vessels than in other tissue; the enzyme, in organs rich in nonvascular smooth muscle, though lower than in blood vessels, was significantly higher than in striated muscle or connective tissue. The localization of benzylamine oxidase activity in smooth muscle, as opposed to connective tissue, may have important physiological implicacations.
Effect of indomethacin on the blood pressure and plasma catecholamine responses to acute endotoxaemia
Authors: FEUERSTEIN G , DIMICCO J A , RAMU A , KOPIN I J 
Published: April 2011

Abstract
Injection of E. coli endotoxin (7 mg kg−1 i.v.) to pentobarbitone anaesthetized cats resulted in prolonged decrease of systemic blood pressure and increases in plasma concentrations of adrenaline, noradrenaline and 6-ketoprostaglandin (PG) F1α. Indomethacin pretreatment (10 mg kg−1 i.v.) attenuated the decrease in blood pressure following endotoxin injection. Plasma adrenaline, noradrenaline and 6-keto-PG F1α were significantly lower in the indo-methacin-treated cats. These data indicate that the superior haemodynamic status of the indomethacin pretreated animals exposed to endotoxic shock is not the result of potentiation of the peripheral sympathetic response.
Thermic and tremorogenic effects of thyroliberin (TRH) in reserpine-treated mice—the non-involvement of GABA-ergic mechanisms
Authors: BJÖRKMAN SVEN , LEWANDER TOMMY , KARLSSON JAN-ANDERS , KOSKINEN LARS-OWE , ZETTERSTRÖM TYRA 
Published: April 2011

Abstract
Administration of thyroliberin (TRH) to reserpinized mice causes tremor and counteracts the hypothermia in a dose-dependent fashion. The thyroliberin response is inhibited by γ-hydroxybutyric acid (GHB) and baclofen, but not by other, more specific GABA-ergic agents, such as THIP, γ-acetylenic GABA, and sodium valproate. Picrotoxin neither potentiates nor inhibits the thyroliberin actions. Nor are the thyroliberin effects dependent on cholinergic, monoaminergic or histaminergic mechanisms. The results repudiate a current hypothesis, that the peptide actions may be mediated by GABA-ergic pathways in the brain.
Changes in seizure susceptibility after successive treatments of mice with tryptophol and ethanol
Authors: FUKUMORI RYUJI , MINEGISHI AKEMI , SATOH TETSUO , KITAGAWA HARUO 
Published: April 2011

Abstract
Changes in leptazol (pentetrazol) seizure susceptibility after successive treatments of mice with tryptophol, a neutral metabolite of indoleamine, in combination with ethanol have been examined. Mice treated with tryptophol plus ethanol became highly susceptible to convulsions. There was little or no difference in seizure susceptibility in mice treated with tryptophol or ethanol alone, compared with the corresponding controls. In the mice treated with tryptophol plus ethanol, a much higher brain tryptophol level was observed, compared with that in mice treated with tryptophol alone. There appeared to be a good correlation between the reduction of the length of the seizure latency time and the time for which the brains were exposed to high levels of tryptophol. These results suggest that elevation of the levels of neutral indoleamine metabolites in the brain may have resulted in the increase in the seizure susceptibility.
The prediction of the bulk densities of powder mixtures, and its relationship to the filling of hard gelatin capsules
Authors: NEWTON J M , BADER F 
Published: April 2011

Abstract
From measurements of the properties of individual components, it has been found possible to predict the maximum tapped bulk density of two component mixtures of a range of particle size fractions of acetylsalicylic acid and lactose in varying proportions. This has been extended to the prediction of bulk density of such mixtures when filled into hard gelatin capsules by a system which results in the powders existing at the maximum tapped bulk density. Consequently the capsule fill weight can also be predicted for such systems. The method is less satisfactory for the prediction of the bulk density and capsule fill weight, when the capsules are filled by a process involving compression of the powder within the capsule shell.
Effects of acute and subacute treatment with ergot drugs on the GABA system in specific brain regions
Authors: PERIČIČ DANKA 
Published: April 2011

Abstract
The effect of dihydroergotoxine and dihydroergotamine on Γ-aminobutyric acid (GABA) levels, the aminooxyacetic acid (AOAA)-induced accumulation of GABA, and the in vitro activity of L-glutamate decarboxylase (GAD) have been examined in various regions of rat brain. Dihydroergotoxine (1 mg kg−1) decreased the concentration of GABA and enhanced the AOAA-induced accumulation of GABA in the caudate nucleus and cingulate cortex. Dihydroergotoxine 10·0 mg kg−1 decreased the AOAA-induced accumulation of GABA in the substantia nigra. The repeated treatment with dihydroergotoxine, 0·05 mg kg−1 for eight days, also decreased the concentration of GABA in the cingulate cortex and diminished the AOAA-induced accumulation of GABA in the substantia nigra. The administration of 0·1 mg kg−1, but not higher doses; of dihydroergotamine, enhanced the AOAA-induced accumulation of GABA in the cingulate cortex. Dihydroergotamine (10·0 mg kg−1) decreased the concentration of GABA in the cingulate cortex and increased the AOAA-induced accumulation of GABA in the caudate nucleus. The activity of GAD in the cingulate cortex, but not in the caudate nucleus, was enhanced after a high dose of dihydroergotamine. Observed increases in the AOAA-induced accumulation of GABA indicate that dihydroergotoxine and dihydroergotamine in at least some brain areas cause an apparent increase in GABA syn-synthesis in vivo, which is presumably a compensatory phenomenon due to a diminished GABAergic transmission under the influence of these drugs.