bluuebunny/crossref_metadata_2025_split huggingface dataset:
Encapsulated hydrophilic polymer beads containing indomethacin as controlled release drug delivery systems
Authors: Suryakusuma H , Jun H W 
Published: April 2011

Abstract
Encapsulated hydrophilic polymer beads containing indomethacin were prepared by a combined technique of bead polymerization and phase separation. The drug delivery system consisted of the copolymer of 2-hydroxyethyl methacrylate and acrylamide as the core matrix and ethyl cellulose as the barrier membrane. The drug was incorporated into the polymer matrix during the formation of the beads. The system was found to be useful as a sustained release dosage form. Release of drug from the coated beads followed a zero-order rate up to 40% of the drug released. A linear relationship exists between the rate of release and the reciprocal amount of ethyl cellulose used for coating, indicating that the drug release was controlled by the coating thickness. Addition of polyvinyl pyrrolidone in the formulation significantly increased the amount of drug released. Blood level studies showed that drug absorption from the encapsulated beads was slower than that of indomethacin powder. It appeared that indomethacin was completely absorbed from the encapsulated beads.
k-Opioid diuretic effects of tifluadom, a benzodiazepine opioid agonist
Authors: Leander J David 
Published: April 2011

Abstract
Tifluadom produced a dose-related (0·08–5 mg kg−1) diuresis in normally hydrated rats. This diuretic effect was antagonized by k-antagonist doses of naloxone and blocked by morphine administration. This is further in-vivo evidence that tifluadom is a fairly specific k-opioid agonist.
Light scattering studies on micelle formation by some penicillins in aqueous solution
Authors: Attwood D , Agarwal S P 
Published: April 2011

Abstract
The aggregation of a number of penicillins, both in water and in electrolyte solution, has been examined by total intensity light scattering methods. Micellar association was noted for carfecillin, flucloxacillin cloxacillin, phenethicillin and penicillin V and critical micelle concentrations and micellar aggregation numbers were determined. Association of penicillin G in water and electrolyte was limited to dimer and trimer formation.
Quantification of uptake of liposomal carboxyfluorescein by professional phagocytes in-vitro. A flow microfluorimetric study on the J774 murine macrophage cell line
Authors: Stevenson M , Baillie A J , Richards R M E 
Published: April 2011

Abstract
Unilamellar egg phosphatidylcholine/cholesterol liposomes containing carboxyfluorescein were prepared by an ether injection method. The ability of cells of the J774.2 murine macrophage cell line to incorporate the liposomal fluorophore during incubation at 37 °C was measured by flow microfluorimetry. Liposomes incorporating additional phosphatidyl-serine or phosphatidic acid were taken up much more avidly than those lacking these phospholipids and the greatest uptake of carboxyfluorescein was observed with the phosphatidylserine species. Calculation of the number of liposomes taken up, &gt;0–2% of the number given, showed that this was an inefficient process. However these uptake data support previous findings based on the intracellular bactericidal activity of liposomal antibiotics determined in an identical in-vitro system.
Application of orthogonal functions to spectrophotometric analysis of the preservatives benzylalcohol, phenol and parabens in aqueous cyanocobalamin solutions
Authors: Girgis Ezzat H , Negm Fatma , Mahmoud Soad 
Published: April 2011

Abstract
The orthogonal polynomials P3 and P2, 12 and 8 points, at 2 nm intervals over certain wavelength ranges were used for the spectrophotometric analysis of benzylalcohol, phenol or parabens in aqueous cyanocobalamin solutions. The 12 point-methods proved to be more sensitive and direct and to have sufficient accuracy and precision.
Photoirradiation products of cyproheptadine and carbamazepine
Authors: Robson Julie K , Sharples D 
Published: April 2011

Abstract
Cyclobutyl dimer and 10,11-epoxide photoirradiation products of cyproheptadine and carbamazepine have been isolated by preparative tlc and identified by tlc, uv, pmr and mass spectroscopy.
On the usefulness of ultrafiltration in drug-protein binding studies
Authors: Zhirkov Yu A , Piotrovskii V K 
Published: April 2011

Abstract
Severe non-specific adsorption of verapamil, nifedipine, prazosin and nadolol was observed during ultrafiltration of the drug solutions through the Centriflo CF 50A, YMT, YMB and Visking membranes. The results question the adequacy of the ultrafiltration procedure for the protein binding assay of the tested drugs.
Murine lymphocytes lack clearly defined receptors for muscarinic and dopaminergic ligands
Authors: Wazer David E , Rotrosen John 
Published: April 2011

Abstract
[3H]Quinuclidinyl benzilate and [3H]spiperone binding to murine lymphocytes is displaceable but differs from binding to brain receptor sites for these ligands: (1) binding to intact lymphocyte preparations was not saturable; (2) disruption of intact lymphocytes was associated with a marked loss of displaceable ligand binding; (3) drugs differentially displace these ligands in lymphocytes compared to brain. Displaceable binding was increased following incubation of lymphocytes under phospholipid methylating conditions; however, marked effects on cell viability and cell recovery make it difficult to interpret these binding changes. If dopaminergic and cholinergic receptors do exist on lymphocytes, their binding characteristics are profoundly different from comparable ens receptors.
Aspects of the cardiovascular pharmacology of exaprolol
Authors: Hughes B , Kane K A , McDonald F M , Parratt J R 
Published: April 2011

Abstract
This study confirms that exaprolol is a potent β-adrenoceptor antagonist, having a pA2 value of 9·8 for the inhibition of the inotropic and chronotropic responses of guinea-pig isolated atrial preparations to isoprenaline. In the anaesthetized cat, exaprolol blocks both the myocardial stimulatory and vasodilating effects of isoprenaline, suggesting that it is a non-selective antagonist at β-adrenoceptors. Exaprolol also has direct electrophysiological effects on cardiac (Purkinje) tissue, reducing the rate of rise of phase 0 of the action potential. This direct action together with its marked blockade of β-adrenoceptors may explain the drug’s ability to markedly suppress the ischaemic ventricular arrhythmias that follow coronary artery occlusion in anaesthetized rats.
The effect of temperature on the α-adrenoceptor antagonist potency of indoramin and labetalol in the rat perfused mesenteric vascular bed
Authors: McAdams R P 
Published: April 2011

Abstract
The effect of reduction in temperature of perfusion from 37 to 27 °C and 20 °C on the ability of the adrenoceptor antagonists indoramin and labetalol to block pressor responses to noradrenaline in the perfused mesenteric vascular bed of the rat was examined. The results suggest that in the rat mesenteric bed, antagonist potency of both agents is increased at low temperatures.
Fluidized bed film coating of an ordered powder mixture to produce microencapsulated ordered units
Authors: Thiel W J , Nguyen L T 
Published: April 2011

Abstract
Very finely divided particulate salicylic acid (2–5 μm) was microencapsulated using conventional fluidized bed coating techniques. The process involved spray coating a preformed ordered mixture, in which the micronized particles are adsorbed on the surface of a coarser carrier material. The mixtures contained 0·1, 1·0 and 5·0% weight of microfine model drug (salicylic acid). Between 75 and 95% of the micronized particles were retained on the carrier surface beneath the film. This process offers a novel method of microencapsulating very fine particulate materials, which may find an application in the production of enteric coated and sustained release microdose products. A recent publication on electrostatic charge interactions in ordered mixtures reported that the addition of a third component can affect the stability of a binary ordered mixture. Addition of 2% talc increased the stability of some mixtures during coating and resulted in the microencapsulation of a significantly greater amount of micronized model drug. A 0·1% salicylic acid binary ordered mixture retained 74% of model drug beneath the film, the 0.1% ternary mixture (2% talc) gave a mean retention of 99%.
Amitriptyline and femoxetine, but not clomipramine or citalopram, antagonize hyperthermia induced by directly acting 5-hydroxytryptamine-like drugs in heat adapted rats
Authors: Pawłowski Leszek 
Published: April 2011

Abstract
5-HT uptake inhibitors and pirenperone (a 5-HT2 receptor antagonist), which in previous experiments antagonized fenfluramine (5-HT releaser)-induced hyperthermia in heat adapted rats, were tested against hyperthermia induced by the directly acting 5-HT agonist—m-CPP and quipazine. Pirenperone and—to a lesser degree—amitriptyline and femoxetine antagonized the hyperthermia. Citalopram and clomipramine were inactive. It is concluded that hyperthermia induced by 5-HT-like drugs in rats is due to the stimulation of the 5-HT2 receptor and that the antagonistic effect of citalopram and clomipramine against fenfluramine-induced hyperthermia might be connected with their effect on the uptake of 5-HT.
Effect of bupropion on dopamine and 5-hydroxytryptamine-mediated behaviour in mice
Authors: Muley M P , Joshi M A , Manekar M S 
Published: April 2011

Abstract
When bupropion (12·5–50 mg kg−1) was administered 30 min before methamphetamine it significantly antagonized methamphetamine-induced stereotyped behaviour in mice, but when given 5 min after methamphetamine it significantly potentiated the behaviour. When it was administered to mice pretreated with 100 mg kg−1 pargyline, intense locomotor stimulation and stereotyped behaviour was observed whereas when clomipramine was administered similarly the animals showed locomotor stimulation, head twitches and abduction and extension of hind limbs. Unlike clomipramine, bupropion failed to potentiate the 5-hydroxytryptamine-mediated behaviour seen after 5-hydroxytryptophan, 100 mg kg−1, i.v. These observations are in agreement with reports that bupropion is more potent as an inhibitor of dopamine uptake than as an inhibitor of 5-hydroxytryptamine uptake in-vitro.
The promotion of drug rectal absorption by water absorption
Authors: Shiga Masaharu , Muraoka Toshiko , Hirasawa Toyoto , Hayashi Masahiro , Awazu Shoji 
Published: April 2011

Abstract
The promotion of the rectal absorption of antipyrine by sodium taurocholate (TC-Na) or sodium ethylenediam-inetetraacetate (EDTA-Na) has been examined by in-situ recirculating perfusion in the rat. These promoters significantly increased water influx, efflux and antipyrine absorption clearance (CLAP). Ouabain treatment significantly reduced the increase in both rectal absorption of drug and water flux. Water absorption dependent on active sodium transport may thus possibly promote the rectal absorption of poorly absorbable drugs.
The affinity and efficacy of naturally occurring catecholamines at β-adrenoceptor subtypes
Authors: McPherson Grant A , Molenaar Peter , Malta Errol 
Published: April 2011

Abstract
The contribution of affinity and efficacy to the agonistic actions of the naturally occurring catecholamines, (-)-noradrenaline and (-)-adrenaline at β-adrenoceptor sites were assessed in guinea-pig driven left atrial (β1) and K+-depolarized uterine (β2) preparations. The dissociation constants of each agonist, required in these calculations, were calculated using radioligand binding techniques. [125I]Iodocyanopindolol bound to sites in membrane preparations of each tissue which have been shown to represent β1(atria) and β2-(uterus) adrenoceptors. It was found that (-)-noradrenaline was approximately 10-fold more selective for the β1- as opposed to the β2-adrenoceptor in the pharmacological studies. Affinity/efficacy calculations indicated that this selectivity was entirely due to a selective affinity for the β1-adrenoceptor subtype. (-). Noradrenaline, (-)-adrenaline and the reference compound (-)-isoprenaline all had approximately the same efficacy at either β-adrenoceptor subtype.
Effect of ergometrine on methamphetamine and apomorphine stereotypy in the guinea-pig
Authors: Balsara J J , Bapat T R , Gada V P , Nandal N V , Chandorkar A G 
Published: April 2011

Abstract
Pretreatment with the DAi receptor antagonist ergometrine (10, 20 mg kg−1 i.p.) significantly potentiated methamphetamine stereotypy and facilitated the induction of biting, gnawing or licking behaviour by amantadine. However, ergometrine (5–20 mg kg−1) did not significantly influence the stereotyped behaviour induced by the DAe receptor agonist apomorphine. The results suggest that the DAi antagonist ergometrine is effective in modifying the behaviours induced by methamphetamine and amantadine, agents which through released DA simultaneously activate both DAe and DAi receptors, but fails to modify the stereotyped behaviour induced by apomorphine which specifically activates only DAe receptors. However, the possibility that ergometrine might have potentiated methamphetamine stereotypy and facilitated the induction of biting, gnawing or licking behaviour by amantadine through modulation of the activity of the central noradrenergic and 5-hydroxytryptaminergic systems, which are reported to influence DA-mediated behaviours, also needs to be considered.
Enhanced bioavailability of insulin after rectal administration with enamine as adjuvant in depancreatized dogs
Authors: Nishihata Toshiaki , Okamura Yasufumi , Kamada Akira , Higuchi Takeru , Yagi Toshihito , Kawamori Ryuzo , Shichiri Motoaki 
Published: April 2011

Abstract
Rectal absorption of insulin by depancreatized dogs was significantly enhanced by the coadministration of enamine as a suppository adjuvant and if this was followed by a further suppository containing enamine alone, the insulin absorption was even further enhanced. The additional enamine suppository resulted in high serum insulin concentrations for a longer time and effected a significant decrease in serum glucose concentrations. To decrease serum glucose concentrations effectively in depancreatized dogs, serum insulin levels had to remain high for a long period of time, rather than be transient.
Absorption through human skin of ibuprofen and flurbiprofen; effect of dose variation, deposited drug films, occlusion and the penetration enhancer N-methyl-2-pyrrolidone
Authors: Akhter Sheikh A , Barry Brian W 
Published: April 2011

Abstract
The penetration of ibuprofen and flurbiprofen, non-steroidal anti-inflammatory agents, was investigated from drug films deposited by acetone evaporation on cadaver skin in an open cell ‘in-vivo mimic’ design. Increased dosage did not produce a proportional increase in the permeation and maximizing the skin-drug contact did not increase penetration: both factors indicate that absorption from deposited drug films was dissolution rate-limited. Occlusion of the skin did not increase the dissolution rate of the deposited drug film, but did elevate the penetration of drug already present within the skin at the time of occlusion. The diffusion coefficients for both drugs were calculated by two methods, yielding 1.8 ± 1.3 times 10−11 cm2 s−1 and 1.0 ± 0.56 times 10−11 cm2 s−1 for ibuprofen and 1.9 ± 0.59 times 10−11 cm2 s−1 and 0.77 ± 0.23 times 10−11 cm2 s−1 for flurbiprofen. Increasing the acetone-skin contact time from 2 min to 2 h did not significantly alter the permeability of the skin. Absorption of flurbiprofen was similar from 10 and 100% saturated aqueous solutions, suggesting that the skin has a limited capacity for flurbiprofen transport beyond which further increase in drug penetration may be difficult. N-Methyl-2-pyrrolidone enhanced the penetration flux of ibuprofen sixteenfold and flurbiprofen, over threefold. The ‘in-vivo mimic’ design for permeation experiments has thus proved to be useful for evaluating the kinetics of topical therapy and the mechanism of action of potential penetration enhancers.
A carrier-mediated transport system for benzylpenicillin in isolated hepatocytes
Authors: Tsuji Akir , Terasaki Tetsuya , Tamai Ikumi , Nakashima Emi , Takanosu Kazuhiro 
Published: April 2011

Abstract
The transport mechanism of benzylpenicillin was studied in freshly prepared rat hepatocytes. The initial uptake rate followed both saturable and unsaturable transport processes. The Arrhenius plot of the initial uptake rate gave an activation energy of 16.8 kcal mol−1 (69 kJ mol−1). The benzylpenicillin uptake by hepatocytes was significantly inhibited by antimycin A, sodium cyanide, rotenone, 2,4-dinitrophenol, phenoxymethylpenicillin, probenecid and Taurocholic acid. No significant inhibition was observed by acetylaminohippuric acid and several kinds of amino acids and dipeptides. The present study provides the first evidence for the the existence of a carrier-mediated and energy-dependent transport system of benzylpenicillin in the liver.
5-Hydroxytryptamine can antagonize the ability of metoclopramide and SCH 23390 to enhance electrical field stimulation-evoked contractions of guinea-pig isolated stomach muscle
Authors: Gunning S J , Naylor R J 
Published: April 2011

Abstract
Electrical field stimulation of guinea-pig stomach strips caused frequency related contractions that were enhanced by metoclopramide and SCH 23390 (10−7 −10−5 M) and antagonized by atropine (5 times 10−8 M. 5-HT (3 times 10−8 −3 times 10−5 M) antagonized the ability of metoclopramide and SCH 23390 to enhance the contractions. It is concluded that metoclopramide and SCH 23390 can enhance electrical field stimulation-induced contractions in the stomach strips by a 5-HT receptor blockade which can facilitate cholinergic mediated contractions.
The adhesion characteristics of some pigmented and unpigmented aqueous-based film coatings applied to aspirin tablets
Authors: Okhamafe Augustine O , York P 
Published: April 2011

Abstract
The adhesion of pigmented (with talc and titanium dioxide) and unpigmented aqueous-based films, derived from hydroxypropyl methylcellulose, to aspirin tablets and the effect of ageing on the measured adhesion have been assessed. The adhesion of hydroxypropyl methycellulose film attained maximum values at polyethylene glycol 400 and polyvinyl alcohol levels of 10 and 20 wt%, respectively. Above these concentrations, adhesion decreased. For solid loaded films it is proposed that the effect of pigments on film adhesion is dependent on the balance between their influence on the internal stress of the film coating and the strength of the film-tablet interface. Adhesion was enhanced when a pigment increased the strength of the interface faster than it increased internal stress, and vice versa. A simple relation between the measured adhesion and the incidence of edge splitting of film-coated tablets was not observed. Generally, film adhesion fell when the tablets were aged at 37°C and 75% r.h. as a result of swelling-induced stresses in the film and at the film tablet interface. The effect of ageing on the adhesion of the system plasticized with polyethylene glycol 400 was eased when the film was pigmented. Adhesion was largely unaffected with film-coated tablets stored in tightly closed bottles at 20°C for five months.
Drug delivery to the proximal colon
Authors: Hardy John G , Wilson Clive G , Wood Elizabeth 
Published: April 2011

Abstract
The transits of a capsule and a multiparticulate pellet system have been monitored through the gastrointestinal tract in six healthy volunteers. Both preparations moved together through the stomach and small intestine, reaching the colon, on average, 4 h after dosing. Within the colon the pellets dispersed and moved at a slower rate than the capsule. There was considerable intersubject variability in the large bowel transit times. The findings are discussed in terms of drug delivery to the colon.
Inhibition of prostaglandin generation in the rabbit brain in-vivo by AD-1590, a non-steroidal antiinflammatory agent with potent antipyretic activity
Authors: Nakamura Hideo , Yokoyama Yuichi , Motoyoshi Satoru , Seto Yasuhiro , Kadokawa Toshiaki , Shimizu Masanao 
Published: April 2011

Abstract
The inhibition of prostaglandin generation by AD-1590 was investigated in the rabbit brain in-vivo. AD-1590 (0&#x006d;̇4 mg kg−1 i.v.) markedly prevented both the increases in body temperature and PGE2 level in cerebrospinal fluid (CSF) caused by i.v. injection of lipopolysaccharide. On the other hand, 2,4-dinitrophenol (20 mg kg−1 i.v.)-induced hyperthermia, which was not affected by AD-1590, was not accompanied by an increase in PGE2 level in CSF. When injected intracerebroventricularly, AD-1590 dose-dependently inhibited the hyperthermia caused by arachidonic acid given by the same route; its ED50 was 1&#x006d;̇6 μg compared with about 35 μg for indomethacin. From these results, it is suggested that AD-1590 is more active than indomethacin in suppressing prostaglandin synthetase in rabbit brain.
Extraction efficiency and biliary excretion of hepatobiliary imaging agents in the rat perfused liver
Authors: Fritzberg Alan R , Reichen Juerg 
Published: April 2011

Abstract
A multitude of transitional metal complexes has recently been introduced into clinical practice as hepatobiliary imaging agents; the kinetics of these substances are often poorly understood. To gain better insight into characteristics of these different agents, we measured the extraction efficiency and mean biliary transit time of a variety of iminodiacetate derivatives in the in-situ rat perfused liver. First pass hepatic extraction efficiency averaged 59% for 99mTc N-(p-isopropylacetanilide) iminodiacetate, 73% for 99mTc N-(2,6-diethylacetanilide) iminodiacetate, 74% for 99mTc N-(3-bromo-2,4,6-trimethylacetanilide) iminodiacetate, 90% for 99mTc N-(p-butylacetanilide) iminodiacetate, and 93% for 99mTc N-pyridoxyl-5-methyltryptophan. By comparison, extraction of another organic anionic compound, 131I Rose bengal, was only 12&#x006d;̇4%. Mean hepatocyte transit times varied from 2&#x006d;̇3 to 7&#x006d;̇5 min. Shorter mean transit times were observed for diortho substituted and longer mean transit times for para substituted metal complexes. Radioactivity was quantitatively recovered in bile, and excretion kinetics overall were consistent with data generated in whole animals. These studies demonstrate the value of the in-situ rat perfused liver as a screening tool to characterize hepatobiliary imaging agents.
Baclofen is a potent activator of brown fat metabolism
Authors: Rothwell N J , Addae J I , Stock M J , Stone T W 
Published: April 2011

Abstract
The injection of (±)-baclofen intravenously or directly into the ventromedial hypothalamus of urethane-anaesthetized rats, produced an activation of brown fat metabolism. This was seen as an increase of brown fat and rectal temperatures, and an increase of GDP binding in brown fat mitochondria. The activation was mediated by the sympathetic supply.