bluuebunny/crossref_metadata_2025_split huggingface dataset:
The measurement of the adhesion of film coatings to tablet surfaces: the effect of tablet porosity, surface roughness and film thickness
Authors: Rowe R C 
Published: April 2011

Abstract
The effect of tablet porosity, surface roughness and film thickness on the adhesion of hydroxypropyl methyl cellulose films to placebo tablet substrates have been studied using a specially designed tensile tester (Fisher & Rowe, 1976). There were direct relations between measured adhesion and tablet porosity and also surface roughness and tablet porosity. The effect of film thickness on the measured adhesion is complex with an initial decrease with thicknesses up to 35 μm and then a gradual increase with thicknesses up to 140 μm due to differences in in the stress distibution within the film during testing. A knowledge of these effects is necessary if results from various sources are to be compared. The findings illustrate the potential capability of the extrapolation of measured adhesion results to zero porosity and zero thickness values in order to obtain a measure of the true or intrinsic adhesion at any film/tablet interface without the confusing elements of tablet porosity, surface roughness and residual stresses in the film.
On methods of expressing dissolution rate data
Authors: Goldsmith J A , Randall N , Ross S D 
Published: April 2011

Abstract
The value of the Weibull, logarithmic-logistic, and logarithmic-normal plots in expressing dissolution rate data is considered for the combinations of zero and first-order release with sink and non-sink conditions, and for actual dissolution rate data of diazepam from tablets in a medium of pH 2.
Investigation of possible interactions between substance P and transmitter mechanisms in the substantia nigra and corpus striatum of the rat
Authors: Starr Michael S 
Published: April 2011

Abstract
The effect of substance P (SP) on the uptake and release of radiolabelled dopamine (3H-DA), 5-hydroxytryptamine (3H-5-HT) and γ-aminobutyric acid (3H-GABA) was studied in slices of rat substantia nigra and corpus striatum. SP, 10−9 to 10−5m, failed to modify the uptakes of these compounds during incubations (10–90 min) with slices of either brain region. SP, 10−6m, had no apparent effect on the spontaneous output of any of these compounds in either substantia nigra or corpus striatum. In the corpus striatum, SP seemed to potentiate the potassium-stimulated outflow of 3H-DA and 3H-5-HT, but not 3H-GABA, while the releases from substantia nigra were unaffected. Morphine (10−3m), but not met-enkephalin (5 × 10−6m), weakly antagonized K+-evoked release of 3H-DA in the corpus striatum. These results are discussed with reference to the possible interaction of SP with transmitter mechanisms at presynaptic sites in the central nervous system.
Quisqualamine, a novel γ-aminobutyric acid (GABA)-related depressant amino acid
Authors: Evans R H , Francis A A , Hunt K , Martin M R , Watkins J C 
Published: April 2011

Abstract
A new substance, quisqualamine, the decarboxylated analogue of quisqualic acid, predictably depressed electrical activity of neurons of the frog and rat spinal cord in vitro and of the mouse spinal cord in vivo. In the in vitro preparations, the action of quisqualamine was associated with a prolonged depolarization of primary afferent terminals which was sensitive to blockade by picrotoxin and bicuculline and which was also depressed by strychnine. This suggests an interaction of quisqualamine with presynaptic receptors for both GABA and β-alanine. Post-synaptic actions of quisqualamine, which were less marked than those at pre-synaptic sites, also appeared to be predominantly GABA-mimetic in vitro, though a sensitivity to the GABA-antagonist bicuculline could not be demonstrated in vivo.
Multiple-scored tablets. Weight and content uniformity of subdivisions and the distribution of active constituent within and between tablets
Authors: Walker John , Abdulsalam Aminah , Theobald Anthony E , Subrahmanyam Rany , Verma Subash K 
Published: April 2011

Abstract
Using three brands of multiple-scored levodopa tablets B.P. (500 mg) and one brand of sulphamethoxypyridazine tablets B.P. (500 mg) the weight and content uniformity of the subdivisions has been examined. It is shown that quartering of such tablets can result in sub-units which do not conform to recognized standards of weight uniformity, and in some instances content uniformity may be questionable. The homogeneity of distribution of active constituent between tablets has been determined and compared with that within tablets (between quarters of individual tablets). Statistical evaluation of the results is presented.
The effect of repeated administration of diftalone on enzyme induction
Authors: Garnham J C , Saunders L , Stainton-Ellis D M , Franklin C , Volans G , Turner P , Natunen T 
Published: April 2011

Abstract
Plasma concentrations of diftalone have been examined in normal volunteers after a single dose (500 mg) and after 500 mg doses given twice daily for one week. An increase in post dosing urinary excretion of D-glucaric acid showed a correlation with the ratio of calculated to observed areas under the plasma concentration, time curve following the final dose in the multiple dosing studies, indicating that hepatic microsomal enzymes are induced after repeated administration of the drug. Single dose studies in the presence of aluminium hydroxide and sodium bicarbonate showed that the antacids had no significant effect on the absorption of diftalone.
Species differences in the in vitro metabolic reduction of the amphetamine metabolite, 1-phenyl-2-propanone
Authors: Coutts R T , Jones G R , Townsend R E 
Published: April 2011

Abstract
Marked differences were observed, in the ability of fortified 9000 g liver homogenate supernatants from three species to reduce 1-phenyl-2-propanone to the corresponding alcohol. This metabolic keto-reduction was negligible in homogenates from the rat and extensive in the rabbit; guinea-pig liver homogenates had intermediate ability. Metabolic oxidation of 1-phenyl-2-propanol was negligible in all three species. The amount of deamination of amphetamine and of N-n-propylamphetamine was approximately equal, in vitro, in rats and guinea-pigs but two to three times greater in liver homogenates from rabbits. Approximately three times more deaminated products were formed from the in vitro metabolism of N-n-propylamphetamine than from amphetamine metabolism by all three species.
The evaluation of cardiovascular drugs in the anaesthetized, unrestrained rat
Authors: Purdy Ralph E , Ashbrook Donald W 
Published: April 2011

Abstract
A method is reported which allows continuous long-term drug administration and simultaneous blood pressure measurement in the unanaesthetized unrestrained rat. The external jugular vein and abdominal aorta were cannulated and the opposite ends of the cannulae were passed subcutaneously and exteriorized at the back of the head. They were then passed through a spring attached at the lower end to the skull and, at the upper end, to a counter-weighted cantilever. In rats so prepared, infusion of angiotensin amide 200 ng kg−1 min−1 caused a rise of blood pressure which lasted the 48 h infusion period. Heart rate decreased initially but recovered within 6 h. Angiotensin amide 30 ng kg−1 min−1, infused up to seven days, was without effect on blood pressure or heart rate, and both doses of angiotensin amide failed to alter cardiac catecholamine turnover. Hydralazine, mecamylamine and clonidine reduced blood pressure to 63, 62 and 84% of control respectively while clonidine induced a transient increase before its depressor effect. Heart rate was increased by hydralazine to 138%, and decreased by clonidine to 74% of control, and was unaffected by mecamylamine. The magnitude of pressor response to noradrenaline, tyramine and angiotensin was reduced by hydralazine and increased by mecamylamine. Clonidine increased the pressor response to angiotensin but had no effect on that to noradrenaline or tyramine.
The relation between molecular connectivity and gas chromatographic retention data
Authors: Millership J S , Woolfson A D 
Published: April 2011

Abstract
The recently developed topological index, molecular connectivity (&cH), has been correlated using multiple regression analysis with gas chromatographic retention time (Rt) for various series of compounds. For saturated and unsaturated aliphatic hydrocarbons, and aliphatic aldehydes, good correlation with log Rt was achieved by one-parameter linear equations in terms of the first-order connectivity index. (1&cH). The equation for aliphatic alcohols required an additional parameter, the valence connectivity (v&cH) for satisfactory correlation. One-parameter equations using 1&cH also gave good correlation with log Rt for three series of drug molecules, amphetamines, barbiturates and phenothiazines. In all cases the equations generated gave good agreement between calculated and observed log Rt values.
The character of the antagonism by polyphloretin phosphate of contractions to prostaglandins E1 and F2α in guinea-pig ileum
Authors: Petkov V , Radomirov R , Petkov O , Todorov S 
Published: April 2011

Abstract
Polyphloretin phosphate (PPP) produced a dose-dependent decrease in the tone and reduction of the spontaneous phasic contractions of the longitudinal muscle of guinea-pig isolated ileum. PPP (100 μg ml−1) after a 2 min contact with the ileum decreased the contractile effects of PGE1 0·1 μM by 40·6 ± 7·4%, of PGE1 0·01 μM by 86·7 ± 3·3% and of PGF2α 0·1 μM by 62·2 ± 8·6%. After 10 min contact of PPP the contractile effect of PGE1 0·1 μM was decreased by 47·7 ± 4·7% and that of PGF2α0·1 μM by 89·6 ± 1·7%. When the contact was longer, PPP showed a pronounced after-effect in respect to the effects of PGE1 and particularly of PGF2α. PPP significantly reduced contractions to 5-HT and BaCl2, but not to acetylcholine, histamine or substance P. The type of antagonism of PGE1 by PPP was examined using cumulative concentration-effect curves for PGE1 in the presence of increasing concentrations of PPP. We conclude that on guinea-pig ileum PPP acts as a non-competitive antagonist of PGE1 and PGF2α.
The effect of microcapsule size on the oxidative decomposition of core material
Authors: Nixon J R , Nouh A 
Published: April 2011

Abstract
The factors that affect the size of microcapsules and the oxidation of their benzaldehyde core have been examined. The pH of the preparation changed the overall size of the microcapsules which reached a maximum diameter at pH 4·1. The size of the core droplets also varied with the preparative pH and their oxidation rate depended on the bulk droplet size rather than their surface area. A rapid oxidation of benzaldehyde associated with the microcapsule wall resulted in a preliminary peak in the oxidation curve. Explanations for these phenomena are discussed.
The wetting of powders of acetylsalicylic acid, salicylic acid, phenacetin and paracetamol
Authors: Fell J T , Efentakis E 
Published: April 2011

Abstract
The wetting of powders of acetylsalicylic acid, salicylic acid, phenacetin and paracetamol has been assessed using methanol-water mixtures to give a range of surface tensions. The results have been interpreted in terms of the critical surface tension, adhesion tension and spreading coefficients. The critical surface tension values are surprisingly low which may be due to adsorption of the methanol at the solid surface, exposing its CH3 group to the liquid. The adhesion tension and spreading coefficient values could be useful guides in formulation.
Structure activity relation for some 1,4-benzodiazepinones: correlation between rate constants for reduction by sodium borohydride and antileptazol ED 50
Authors: Ramanujam V M Sadagopa , Trieff Norman M 
Published: April 2011

Abstract
Significant correlation in 11 different 1,4-benzodiazepinones has been established between log k2 (the second order rate constant for the reduction of the ‘azepinones’ by sodium borohydride) and their ED50 against leptazol-induced seizures in mice. The results suggest a possible involvement of the carbonyl group at the receptor site.
The antitussive actions of the drug Ru 20201 given as an aerosol to cats
Authors: Korpas J , Nosalova G , Widdicombe J G 
Published: April 2011

Abstract
The effect of the drug Ru 20201 (1,2,3,4,4a,9b-hexahydro-8,9b-dimethyl-4-[3-(4-methylpiperazin-1-yl)propionamido]dibenzofuran-3-one upon mechanically-evoked cough from the laryngopharyngeal and tracheobronchial areas in nine unanaesthetized cats has been examined. Inhalation of 2 ml of an aerosol of a 10% solution in water suppressed coughing for 30 min. The effect was greatest on the number of cough efforts. The expiratory component of cough was suppressed more than was the inspiratory one. The effect was greater on cough from the laryngopharyngeal than from the tracheobronchial area.
Involvement of mesolimbic and extrapyramidal nuclei in the motor depressant action of narcotic drugs
Authors: Costall B , Fortune D H , Naylor R J 
Published: April 2011

Abstract
The ability of narcotic drugs to induce motor depression from the mesolimbic nucleus accumbens (ACB) and extrapyramidal caudate-putamen (CP) was investigated using the bilateral intracerebral injection technique. Fluphenazine and procaine were used as control agents. Firstly, drugs were injected alone into the ACB or CP and catalepsy was assessed. Fentanyl (2·5–10μg), sufentanil (0·25–1 μg) and carfentanil (0·05–0·5μg) were shown to be potent cataleptogens when injected into both the ACB and CP, the responses being dose-dependent and achieving maximum intensity. Morphine (1–50 μg) also induced a marked dose-dependent catalepsy, but only after injection into the ACB. In contrast, pethidine and methadone, in doses up to 160 μg, caused only weak and inconsistent responses from the ACB and CP. Similar injections of procaine (50–200 μg) were ineffective, but fluphenazine (25–200 μg) induced a moderate dose-dependent response from both the ACB and CP, although onset of action was more rapid and the duration markedly longer for the latter injections. Secondly, drugs were injected peripherally and intracerebrally to determine their ability to antagonize the marked hyperactivity induced by intra-ACB dopamine in the presence of nialamide. Two agents shown to induce catalepsy from the ACB, fluphenazine and morphine, antagonized dopamine hyperactivity when they were administered peripherally or directly into the ACB (0·1–0·2 mg kg−1, i.p. or 3·1–25 μg fluphenazine and 1–5 mg−1 kg, s.c. or 1–5 μg morphine), but only a weak antagonism occurred at much larger doses after intra-CP injections (100 μg fluphenazine and 50 μg morphine). Larger doses of intra-ACB pethidine (160 μg) and procaine (100–200 μg) also antagonized the dopamine response, but methadone was inactive. Again, the most potent and effective drugs in this test were fentanyl (1–5 μg), sufentanil (0·25–0·5μg) and carfentanil (0·05–0·1 μg). It is suggested that the ACB, and not the CP, is the site at which morphine acts to cause motor depression, whilst other narcotic drugs are able to act in both areas (although there is some indication of a further unspecified site of action for methadone). In contrast, the neuroleptic fluphenazine appears to differentially affect motor function via the ACB and CP, antagonizing a dopamine hyperactivity in the former and primarily inducing catalepsy from the latter nucleus.
Opiate-receptor mediated changes in monoamine synthesis in rat brain
Authors: Garcia-Sevilla J A , Ahtee Liisa , Magnusson T , Carlsson A 
Published: April 2011

Abstract
The effects of morphine, β-endorphin, naloxone and naltrexone on the rate of tyrosine and tryptophan hydroxylation were investigated in vivo by measuring the accumulation of dopa and 5-hydroxytryptophan (5-HTP) in different brain regions of rats after inhibition of the aromatic L-amino acid decarboxylase. The cerebral concentrations of tyrosine and tryptophan were also measured. Morphine (3–30 mg kg−1) increased the accumulation of dopa dose-dependently (25–50%) in the dopamine-rich areas (limbic forebrain and corpus striatum). In the noradrenaline-predominant parts of the brain (containing hemispheres, diencephalon and lower brain stem) only the highest dose of morphine (30 mg kg−1) significantly increased dopa formation (47%). Similarly to morphine, intracerebroventricularly injected β-endorphin (5–10 βg per rat) increased the formation of dopa. This increase was doubled in limbic forebrain, corpus striatum and cerebral hemispheres. Doses of 10 to 20 μg of β-endorphin were needed to increase dopa accumulation in the diencephalon and the lower brain stem. Naloxone antagonized the β-endorphin-induced increases in dopa. But naloxone and naltrexone (10–100 mg kg−1) decreased the dopa formation in the dopamine-rich areas (about 20–25 %) but not in the noradrenaline-predominant areas. Morphine (30 mg kg−1) and β-endorphin (5 μg per rat) increased the accumulation of 5-HTP whereas naloxone and naltrexone (10 mg kg−1) tended to decrease its formation. Morphine and β-endorphine increased the concentrations of tyrosine and tryptophan, and naloxone decreased the cerebral tryptophan concentration. These results show that the effects of a narcotic agonist (morphine) and of pure narcotic antagonists (naloxone and naltrexone) on the synthesis of dopamine and 5-HT are opposite to each other. Furthermore, the effects of β-endorphine on brain monoamine synthesis are remarkably similar to those of morphine. Thus, it is probable that opiate receptors and their endogenous ligands are involved in the regulation of dopamine and 5-HT synthesis.
Effects of temperature on the tensile strength of pharmaceutical powders
Authors: Britten J R , Pilpel N 
Published: April 2011

Abstract
Measurements have been made of the tensile strengths of fatty acids, lactose and of an oxtetracycline and a paracetamol tablet formulation at temperatures between −20 and +90°. The measurements were made on compressed tablets and on consolidated beds of powders, using a diametral compression tester and a split plate tensile tester which had been designed to operate over this range of temperature. The tensile strengths of all the materials increase with temperature and values are given for the activation energies of bonding between particles.
Chlorhexidine kinetics of hydrophilic contact lenses
Authors: MacKeen Donald L , Green Keith 
Published: April 2011

Abstract
An average chlorhexidine concentration of 4·5 μg mg−1 lens (wet weight) was measured in HEMA-based contact lenses after 16 days of the following treatment. The lenses were maintained 16 h daily in 1·5 ml of a solution containing Chlorhexidine digluconate 0·005%, and then worn by adult albino rabbits 8 h daily. Similarly maintained, but unworn lenses contained approximately 23 μg Chlorhexidine mg−1 wet lens weight after 16 days. A plot of the results indicates that continued exposure to Chlorhexidine following initial immersion increased its concentration in unworn lenses while that in the worn lenses reached a peak at 8 days, then decreased slightly in the subsequent days of wearing. Continuous exposure of lenses to the disinfecting solution (1 lens/167 ml) in which the Chlorhexidine concentration was maintained at 0005% for 16 days gave a maximal concentration of 44 μg mg−1 wet lens weight. The comparatively small concentration in a worn lens results from: (1) daily loss from the lens during wear, a large percentage of which is apparently absorbed to tear proteins which subsequently flow from the eyes via the canaliculi; (2) limited uptake because of the small immersion volume employed in routine storage; and (3) the possible competition between Chlorhexidine and tear components for lens binding sites or establishment of an equilibrium condition between uptake and release.
Distribution of pellets in the gastrointestinal tract. The influence on transit time exerted by the density or diameter of pellets
Authors: Bechgaard Helle , Ladefoged Karin 
Published: April 2011

Abstract
The influence on transit time exerted by the density or diameter of pellets has been established in six ileostomy subjects. An increase in density from 1·0 to 1·6 significantly increased the average transit time of pellets in the small intestine. The average transit time for the light and heavy pellets being 7 and 25 h respectively. The diameter of pellets is of minor significance. The findings suggest the use of density as a means of modifying the period of absorption of controlled-release pellets.
Content uniformity of potent drugs in tablets
Authors: Orr N A , Sallam E A 
Published: April 2011

Abstract
The type of distribution of low dosage drugs that occurs in batches of commercially available tablets has been examined. The uniformity of content of ethinyloestradiol tablets 10 μg B.P. from different sources, assessed by single tablet assay showed that three batches exhibited some positive skewness and one marked positive skewness. At the high level of dilution required, the mixing theory indicates that particles of drug must be very fine if acceptable content uniformity is to be obtained. Cohesion of particles impairs the efficiency of the mixing process. It is shown theoretically that unless the drug is dispersed into its component particles the shape of the distribution curve for the content of drug per tablet, in a batch of tablets, will be positively skewed. The relation between the tensile strength of the powdered drug and the degree of skewness of the drug content is also discussed. A positively skewed distribution for tablets containing a small amount of potent drug is unacceptable because this can lead to the presence of relatively large doses of drug in a single tablet. Where one unexpectedly high result occurs in the quality control of the content uniformity of tablets containing potent drugs it is suggested that sufficient single tablet assays be performed to allow the shape of the distribution curve to be assessed. A test for skewness should be included in compendial standards.
The effects of a decarboxylase inhibitor, benserazide, on both thermoregulation and chlorpromazine-induced hypothermia in rats
Authors: Lin M T , Chow C F , Chern Y F 
Published: April 2011

Abstract
Intraperitoneal administration of a peripheral decarboxylase inhibitor benserazide (Ro4–4602) to unanaesthetized rats produced alterations in body temperature which depended on ambient temperature. In the cold, hypothermia was brought about by a decrease in metabolic heat production. At room temperature, a dose-dependent hypothermia was preceded by a slight hyperthermia. The hypothermia was due to an increase in skin temperature (tail) and a decrease in metabolic heat production, while the hyperthermia was due to a decrease in skin temperatures (both tail and footsole) and an increase in metabolic heat production. In the heat, hyperthermia responses to benserazide were associated with decrease in skin temperature (both tail and footsole). Benserazide treatment produced no significant change in brain 5-HT content. Chlorpromazine-induced hypothermia was greatly enhanced after pretreatment of the animals with benserazide at room temperature (22°).