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At least 1,063 records · Page 59Linked to original sources
PubMed1991

Cimetidine suspension in patients with stage 0 gastro-oesophageal reflux disease.

One hundred and twenty-five patients with symptoms of heartburn and acid regurgitation but without endoscopic abnormalities were randomized to receive 200 mg cimetidine suspension four times daily or placebo for two weeks. Daily dairy cards were kept to evaluate the frequency and degree of symptoms. At two weeks cimetidine was significantly more effective than placebo. It is concluded that placebo suspension has a considerable effect on gastro-oesophageal reflux disease symptoms, but cimetidine suspension provides significantly better relief.

Adolescent↗
PubMed1991

Relationship between systemic drug absorption and gastrointestinal transit after the simultaneous oral administration of carbamazepine as a controlled-release system and as a suspension of 15N-labelled drug to healthy volunteers.

1. Plasma drug concentrations after a single oral administration of a suspension of carbamazepine (CBZ) and a 20/200 CBZ Oros osmotic pump system were measured in eight healthy male volunteers. The oral suspension contained 100 mg CBZ labelled with the stable isotope nitrogen-15, whilst the Oros contained 200 mg unlabelled CBZ. Plasma concentrations of [15N]-CBZ and CBZ were measured simultaneously by gas chromatography-mass spectrometry. 2. The position of the CBZ Oros (labelled with indium-111) in the gastrointestinal tract was followed by gamma scintigraphy. Plasma drug concentrations after the two treatments were used to relate pharmacokinetic with transit data. 3. The Oros was taken after breakfast and gastric emptying occurred between 1.1- greater than h post-dosing (median, 5.3 h). Small intestinal transit times ranged from 1.5- greater than 3.6 h, with a median of 2.2 h. There were wide individual variations in colonic transit, and the total transit time ranged from 10-60 h (median, 22 h). 4. Relative systemic bioavailability of CBZ from the Oros was reduced compared with that from the suspension (mean dose normalised AUC ratio = 0.69 +/- 0.17; mean dose-normalised AUC ratio = 0.85 +/- 0.13, allowing for actual release from the Oros system). 5. The in vivo absorption of drug into the systemic circulation from the Oros was estimated using the Wagner-Nelson method. This showed that absorption of CBZ was rapid when the Oros was present in the stomach and small intestine, the rate being determined by the release of drug from the system.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1986

Establishment and growth kinetics of the mutant Ehrlich-Lettré ascites cell strain HD33 in permanent suspension culture.

Cells of a mutant in vivo subline of the Ehrlich-Lettré mouse ascites tumour (ELAT) were converted to growth in suspension culture. Kinetic analysis revealed the selective character of the conversion process; without a detectable adaptation period, a fraction of about 2 X 10(-5) of the explanted cells continued to grow in vitro. The resulting, mutant Ehrlich-Lettré ascites cell strain was designated HD33 and propagated uninterruptedly from 1974 on. The corresponding in vivo ELAT subline HD33 was derived from the HD33 ascites cell strain by intraperitoneal retransplantation. In HD33 cell suspension cultures, the population doubling time, the average intermitotic interval, as determined by videomonitoring, and the average duration of the cell cycle, as determined from percentage of labelled mitoses (PLM) data, were all measured at 15 hr. Cell loss and quiescent compartments were insignificant. The duration of the G1 phase was effectively zero. Both PLM data and [3H]/[14C] thymidine double-labelling measurements revealed an S-phase duration of between 11 and 12 hr. The G2 phase lasted 3-5 hr. The HD33 strain differs from comparable suspension strains of wild-type Ehrlich ascites cells in the insignificant role of density-dependent inhibition in growth, and the striking prolongation of the S phase which is associated with an excessive, cytoplasmic storage of glycogen by the mutant cells.

Animals↗
PubMed1994

Stability of dantrolene oral suspension prepared from capsules.

The chemical stability of an extemporaneously compounded dantrolene oral suspension (5 mg/ml dantrolene sodium) in Syrup BP containing citric acid with and without methyl hydroxybenzoate preservative was studied on storage at 5, 25 and 40 degrees C for 150 days in high density polyethylene dispensing bottles. The amount of dantrolene free acid in suspension was monitored by a stability indicating HPLC assay. There was no significant decomposition of dantrolene under all storage conditions irrespective of the presence of preservative. The results show that the formulation of dantrolene oral suspension provides a convenient and stable dosage form for use in pediatric patients and in those unable to swallow capsules. It is recommended that the formulation be stored at room temperature and in the absence of microbiological testing a shelf-life of 30 days is proposed for the product prepared with preserved syrup.

Capsules↗
PubMed1994

Stability of metronidazole benzoate in suspensions.

A stability-indicating HPLC assay method has been developed to quantify metronidazole benzoate in suspensions. A study of the stabilities of two suspensions (16.0 mg/ml) of metronidazole benzoate in commercially available vehicles, Ora-Plus and a mixture of Ora-Plus and Ora-Sweet, showed that both suspensions were stable for at least 90 days at room temperature. The mobile phase required to elute metronidazole benzoate contained 40% acetonitrile versus approximately 10% for the free base. The solubility of the ester in water at 25 degrees C was found to be approximately 0.1 mg/ml versus 10 mg/ml for the free base. The ester did not hydrolyse significantly to the free base after storage for 8 h at 37 degrees C in simulated gastric fluid, and 5 h at 37 degrees C in simulated intestinal fluid. The bitter tasting metronidazole may not be satisfactorily substituted with its tasteless ester in the treatment of local gastrointestinal infections.

Chromatography, High Pressure Liquid↗
PubMed1988

T-cell response to purified protein derivative after removal of Langerhans' cells from epidermal cell suspensions containing keratinocytes expressing class II transplantation antigens.

In a previous study we observed that human epidermal cell (EC) suspensions containing HLA-DR-expressing keratinocytes showed an amplified T-cell response to purified protein derivative (PPD). To evaluate further the possible immunological importance of class II transplantation antigens on keratinocytes we have compared the T-cell response to PPD in the presence of the following stimulator cells: EC suspensions from normal skin, or EC from tuberculin-reactive skin with or without removal of Langerhans' cells. The proliferation of purified T lymphocytes from peripheral blood in response to PPD in the presence of various concentrations of autologous EC was measured by [3H]thymidine incorporation on day 6. In 3 experiments out of 4 the EC from tuberculin-reactive skin, containing 28-76% HLA-DR-expressing cells as judged by immunocytochemistry (which also revealed fairly numerous HLA-DQ/-DP-expressing keratinocytes and a slight increase in CD36- and CD4- but not CD1-expressing cells), induced a more pronounced T-cell response to PPD than did normal EC. This was not the case in the fourth experiment, in which a small number of HLA-DR-(15%) and few if any HLA-DQ-/-DP-expressing keratinocytes were found. Immunomagnetic removal of CD1-reactive Langerhans' cells from the tuberculin-reactive EC suspensions resulted in a reduction of the T-cell response to PPD, in most cases down to background level (T cells alone + PPD). This study does not support the hypothesis that HLA-DR-expressing keratinocytes can in themselves act as antigen-presenting cells.

Adult↗
PubMedDate not supplied

Effects of enteral tube feeding on the absorption and pharmacokinetic profile of carbamazepine suspension.

In a randomized, two-period crossover clinical study, eight normal male volunteers received two separate 500-mg doses of carbamazepine (CBZ) suspension 1 week apart. One dose was administered orally after an overnight fast, and the other was administered by nasogastric feeding tube during a continuous enteral feeding infusion. Serial serum CBZ concentrations were determined by high-performance liquid chromatography (HPLC) to assess the effects of the enteral feeding on CBZ absorption. Noncompartmental methods were used to estimate pharmacokinetic data. One volunteer experienced a mild hypersensitivity reaction after his first CBZ dose and was withdrawn from the study. The other subjects tolerated both doses very well, although most experienced mild drowsiness or lightheadedness. Serum CBZ concentrations were lower during enteral feeding administration, but the differences were statistically significant only at 8 h (p = 0.044). Changes in pharmacokinetic data were not significant, although the decrease in maximum serum concentration approached significance (p = 0.052). The relative bioavailability of CBZ suspension with enteral feeding administration was 90.1% of that during fasting. There was a strong correlation between CBZ dose (mg/kg) and Cmax after oral administration (r = 0.97, Y = 1.88X - 4.49, p less than 0.001) but not during enteral feeding administration. Although absorption of CBZ suspension was generally slower and slightly diminished during nasogastric feeding, this interaction may lessen unwanted side effects.

Absorption↗
PubMedDate not supplied

Optimized delivery of skin keratinocytes by aerosolization and suspension in fibrin tissue adhesive.

Aerosolized suspensions of keratinocytes provide a potential therapy for wounds, but the effects of aerosolization on cell viability remain unclear. Likewise, little is known of the resulting cell distribution pattern and how this compares to the density required for epithelialization. The potential benefits of cospraying cells in the presence of fibrin adhesive are equally uncertain. Thus, in the present study we have optimized conditions for the aerosolization of cultured keratinocytes using a device (Tissomat) that supports the option for coapplication with fibrin (Tisseel). Cell viability was unaffected when sprayed at 10 psi, but a significant reduction in metabolic activity, as determined by the methylthiazoyldiphenol-tetrazolium assay, was observed at higher pressure. Bursts of 0.2 mL cell suspension (1.5x10(6)/mL) delivered from a height of 10 cm was sufficient to epithelialize an area of 10-15 cm2 within 7 days in vitro. Confluent areas corresponded to those with a density of 5,000-10,000 cells/cm2 at 24 hours. Optimal cell growth in Tisseel was achieved through dilution of fibrinogen (1-3 mg/mL) and thrombin (2-5 IU/mL). This optimized formulation eliminated fluid run-off postspraying and stimulated a twofold increase in cellular response. Therefore, our in vitro data supports the theory that aerosolized suspensions of keratinocytes in fibrin will benefit healing.

Aerosols↗
PubMed1989

Enhancement of heat transfer in red cell suspensions in vitro experiments.

New data on laminar heat convection with red cell suspensions have been gathered for both heating and cooling. When compared to data for the suspending medium alone, it is apparent that the red cells enhance laminar heat transfer when Pe greater than 4. This is probably due to particle movements. These new data disagree with earlier studies which indicated no enhancement of heat transfer for blood cell suspensions. The data do agree with previous correlations for enhanced thermal transport in sheared suspensions.

Erythrocytes↗
PubMed1996

Effect of static pressure on acoustic transmittance of Albunex microbubble suspensions.

Albunex (ALX), an albumin-stabilized microbubble echo contrast agent, is sensitive to pressures similar to those produced by the heart. The tested hypothesis was that the acoustic transmittance of ALX suspensions will increase with increasing hydrostatic pressure (Ps). The test involved an acoustic setup analogous to a spectrophotometer. The acoustic transmittance of microbubble suspensions was strongly Ps dependent. Transmittance at 1 MHz was essentially zero at ambient pressure, increasing to approximately 50%, approximately 63%, and nearly 100% at Ps of 80, 120, and 400 mm Hg, respectively. The ultrasound pulses used to interrogate samples were without measurable effect on the acoustic transmittance of suspensions maintained at ambient pressure during experimental measurements. The data indicate that many of the microbubbles are destroyed at Ps comparable to those produced by the heart.

Acoustics↗
PubMed1998

Broadband measurements of phase velocity in Albunex suspensions.

The phase velocities in suspensions of Albunex, an ultrasound contrast agent, are determined using the technique of broadband phase spectroscopy. In these suspensions, phase velocities were measured as a function of Albunex concentration in Isoton II (buffered saline). The dispersion over the measurement bandwidth (1-15 MHz) grew with increasing Albunex concentration, exhibiting a 221-m/s change (17% increase) in phase velocity between 1.0 and 3.8 MHz at the highest concentration reported (32 microL Albunex/8 mL Isoton). The dispersion behavior of the Albunex suspensions is described using a model of encapsulated gas bubbles. The influence of the dispersion in Albunex on broadband pulses is discussed, as well as the potential impact this dispersion may have on the formation of ultrasonic images of the heart.

Albumins↗
PubMed1990

Use of extracts versus whole-cell bacterial suspensions in the identification of Staphylococcus aureus beta-lactamase variants.

We previously have shown that extracts of S. aureus isolates which produce the recognized serotypes of staphylococcal beta-lactamase (A, B, C, D) differ in the rates at which they hydrolyze selected cephalosporins, exhibiting substrate profiles which are distinctive for each serotype. In an effort to simplify the methods employed in identifying the different staphylococcal beta-lactamases, we evaluated whether distinctive substrate profiles could be obtained by using whole-cell suspensions of 115 beta-lactamase-producing isolates of S. aureus. Compared with extracts from the same strains, the whole-cell bacterial suspensions not only were simpler to prepare but enabled beta-lactamase typing of a higher proportion of the evaluated strains (86 versus 97%, respectively). Furthermore, the use of whole-cell bacterial suspensions enabled the simultaneous quantitation of the beta-lactamase activity exhibited by each strain. Additionally, by comparing the quantitative activity of beta-lactamase-induced and -uninduced preparations of the same strain, induction ratios (i.e., induced/uninduced activity) could be derived, yielding information regarding the regulation of beta-lactamase production by each strain. We believe that the utilization of whole-cell methods, such as those employed in this study, will facilitate the investigation of qualitative and quantitative differences in beta-lactamase production among clinical and reference isolates of S. aureus.

Cell-Free System↗
PubMed1986

Bioluminescence for USP sterility testing of pharmaceutical suspension products.

Bioluminescence measurement significantly improved the accuracy, sensitivity, precision, and reliability of the current visual endpoint determination for the USP sterility test and eliminated the day 7 transfer/dilution step required for testing suspension products. Thirteen strains of bacteria and fungi (representing potential contaminants in sterile products), three pharmaceutical suspension products, and four media were used in the experiment. No interference from suspension products was encountered in the detection of microbial growth by the bioluminescence measurement. The poor fungal growth encountered was attributed to insufficient diffusion of oxygen into the medium and was circumvented by use of a large tube size (38 by 200 mm) or by vortexing the medium once during the 2-week incubation period. Bioluminescence measurement would facilitate automated handling of the sterility test endpoint readout operation. The optimum parameters of bioluminescence measurement for application in sterility testing were determined.

Bacteria↗
PubMed1963

INCIPIENT GERMINATION IN HEAVY SUSPENSIONS OF SPORES OF BACILLUS STEAROTHERMOPHILUS AT SUBMINIMAL GROWTH TEMPERATURES.

Curran, Harold R. (U.S. Department of Agriculture, Washington, D.C.), and Michael J. Pallansch. Incipient germination in heavy suspensions of spores of Bacillus stearothermophilus at subminimal growth temperatures. J. Bacteriol. 86:911-918. 1963.-By use of spore (plate) counts and permeability to stain, labilization was followed periodically in heavy suspensions of washed Bacillus stearothermophilus 1518 spores incubated at different temperatures. Although vegetative proliferation did not occur below 38 C, incipient germination was rapid down to 20 C and much slower and incomplete at 14 C. Dilution of the suspension materially reduced the degree and rate of labilization. The degree of washing and use of deionized water had no appreciable influence upon early development of the spores. The results are discussed from the point of view of the possible origin and nature of the germination stimulant.

Bacillus↗
PubMed1964

PATHWAYS FOR BIOSYNTHESIS OF A BACTERIAL CAPSULAR POLYSACCHARIDE. IV. CAPSULE RESYNTHESIS BY DECAPSULATED RESTING-CELL SUSPENSIONS.

Juni, Elliot (Emory University, Atlanta, Ga.), and Gloria A. Heym. Pathways for biosynthesis of a bacterial capsular polysaccharide. IV. Capsule resynthesis by decapsulated resting-cell suspensions. J. Bacteriol. 87:461-467. 1964.-Methods were devised for stripping capsules from encapsulated bacteria. By use of stripped resting-cell suspensions of a gram-negative capsule-forming coccus, it was shown that polysaccharide capsule resynthesis depends upon the presence of air and an oxidizable substrate. Capsule resynthesis proceeds linearly with time. For a given quantity of stripped cells, the net amount of polysaccharide capsule synthesized is a linear function of the amount of substrate oxidized. The only factor that appears to limit the extent of capsule synthesis by resting cells is the amount of substrate utilized. A series of photomicrographs of wet mounts made in India ink show the appearance of stripped cells and resynthesized capsules formed during oxidation of pyruvate and glucose by stripped resting-cell suspensions.

Acetates↗
PubMed1989

Extracellular Na+ electrode for monitoring net Na+ flux in cell suspensions.

A computer-linked extracellular sodium-sensitive electrode system is described that is suitable for the routine measurement of net Na+ transport in cell suspensions. The commercially available Na+ electrode exhibited high selectivity for Na+ over other cations and a rapid response time (less than 3 s). This system resolved changes of 0.4 mM in the presence of 147 mM extracellular Na+. Measurements of Na+ transport in suspensions of rabbit proximal tubules showed that ouabain caused a dose-dependent net Na+ influx with an inhibitor constant (Ki) of 2.5 +/- 0.2 microM and a maximal velocity (Vmax) of 229 +/- 7 nmol Na+.min-1.mg protein-1. This compared favorably with the ouabain-induced K+ efflux (Ki = 2.4 microM; Vmax = 160 +/- 3.3 nmol K+.min-1.mg protein-1) and the ouabain-induced inhibition of respiration (Ki = 3.3 microM; Vmax = 11.8 nmol O2.min-1.mg protein-1). In addition, Ba2+, a K+ channel blocker known to depolarize the cell, caused a net Na+ efflux, whereas glucose, a Na+-cotransported solute, promoted a net Na+ influx. This system should be a powerful tool for continuous monitoring of net Na+ fluxes in cell suspensions.

Animals↗
PubMed1993

A novel morphine sulphate preparation: clinical trial of a controlled-release morphine suspension in cancer pain.

In order to determine the efficacy of a novel controlled-release morphine suspension, we performed two prospective sequential open-label studies in patients with pain due to cancer. The studies were identical except for the duration of treatment (three days and 30 days respectively). Sixty-nine patients with a variety of advanced cancers and associated pain participated. Fifty-three patients completed the trials, 38 on the three-day trial and 15 on the 30-day trial. In both groups the amount of morphine required to obtain pain relief was initially established using controlled-release morphine tablets and immediate-release morphine for 'rescue' dosing. Patients were begun on equivalent doses of the study drug in place of the controlled-release tablets. No differences in pain score or the amount of 'rescue' morphine were noted following the switch to the controlled-release morphine suspension. Toxicity was as anticipated for the use of morphine in this situation and no adverse effects were observed during administration of the suspension. These data suggest that this new formulation of morphine is equipotent to conventional controlled-release morphine tablets and provides pain relief for a 12-hour dosing interval. This novel morphine formulation could be especially useful for paediatric patients and for those who have difficulty in swallowing.

Adult↗
PubMedDate not supplied

Efficacy and tolerance of naproxen instant suspension formulation: a post-marketing survey.

A multi-centre uncontrolled clinical trial was performed in 42 Italian hospitals to evaluate the efficacy and tolerance of an instant suspension of naproxen, a well known anti-inflammatory drug. A total of 390 adults of all ages with musculoskeletal rheumatic diseases or minor traumatic injuries entered the trial. Patients received 500 mg naproxen instant suspension twice daily after meals, for 1-4 weeks. Assessment of signs and symptoms was made before starting the therapy, after 3 days and at the end of the treatment period. The drug produced a rapid and progressive relief of pain and articular symptoms in most patients and was equally effective in all the diagnostic sub-groups. The efficacy of treatment was 'excellent' or 'good' in about 85% of patients, 'moderate' in 10% and 'minimal' or 'absent' in about 5%. Almost 90% of patients had no side-effects; 5% were withdrawn because of unwanted effects. No correlation between incidence or intensity of side-effects and age of the patients or duration of therapy was observed. The complaints reported are common to other anti-rheumatic drugs, e.g. epigastric pain, pyrosis, nausea, vomiting and headache. In conclusion, naproxen instant suspension is highly effective and well tolerated.

Adolescent↗