The Experts below are selected from a list of 297 Experts worldwide ranked by ideXlab platform
C Cruz - One of the best experts on this subject based on the ideXlab platform.
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serum activity concentration profiles of a Sustained Released Formulation of sulphathiazole trimethoprim 2 5 1 in calves
Veterinary Record, 2004Co-Authors: H Sumano, L Gutierrez, M A Zamora, M Perez, C CruzAbstract:Thirty-six two-week-old healthy Holstein-Friesian calves weighing between 52 and 58 kg were divided at random into three groups of 12; group A calves were given a single oral bolus containing 2.5 g sulphathiazole and 1 g trimethoprim in a Sustained-Release Formulation; group B received the same doses of the drugs but the trimethoprim was not in a Sustained-Release Formulation; group C received a bolus containing 2.5 g sulphathiazole and 0.5 g conventional trimethoprim. Blood samples were collected at intervals for two days, the serum was separated and the composite antibacterial activity profiles of the mixture were analysed by an agar-diffusion microbiological method. The mean maximum activities in the serum of the three groups were 23.4 microg/ml in group A, 9.25 microg/ml in group B and 8.01 microg/ml in group C. The mean areas under the curves of the serum activity time curves were 838 microg/ml/hour in group A, 216 microg/ml/hour in group B and 182 microg/ml/hour in group C.
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Serum activity/concentration profiles of a Sustained-Released Formulation of sulphathiazole-trimethoprim (2˙5:1) in calves
The Veterinary record, 2004Co-Authors: H Sumano, L Gutierrez, M A Zamora, M Perez, C CruzAbstract:Thirty-six two-week-old healthy Holstein-Friesian calves weighing between 52 and 58 kg were divided at random into three groups of 12; group A calves were given a single oral bolus containing 2.5 g sulphathiazole and 1 g trimethoprim in a Sustained-Release Formulation; group B received the same doses of the drugs but the trimethoprim was not in a Sustained-Release Formulation; group C received a bolus containing 2.5 g sulphathiazole and 0.5 g conventional trimethoprim. Blood samples were collected at intervals for two days, the serum was separated and the composite antibacterial activity profiles of the mixture were analysed by an agar-diffusion microbiological method. The mean maximum activities in the serum of the three groups were 23.4 microg/ml in group A, 9.25 microg/ml in group B and 8.01 microg/ml in group C. The mean areas under the curves of the serum activity time curves were 838 microg/ml/hour in group A, 216 microg/ml/hour in group B and 182 microg/ml/hour in group C.
J. Moncrieff - One of the best experts on this subject based on the ideXlab platform.
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The effects of omeprazole-induced hypochlorhydria on absorption of theophylline from a Sustained-Release Formulation
European Journal of Clinical Pharmacology, 1992Co-Authors: K. Sommers, J. R. Snyman, J. MoncrieffAbstract:The present study was designed to investigate the effects of raised intragastric pH on the absorption of theophylline from a Sustained-Release Formulation. Six healthy male volunteers participated in the cross-over randomised study and on one of two occasions were pretreated with 240 mg omeprazole, administered in three divided doses over the 22 h preceding the test. The sulphasalazine/sulphapyridine method of assessing oral-caecal transit time was implemented in order to assess upper bowel and colonic absorption. The mean fraction absorbed — time profile was calculated from serial serum theophylline concentration measurements by a modification of the Wagner-Nelson equation. During hypochlorhydria the mean oral-caecal transit time was 4.6 h, mean time to 90% absorption 6.8 h, and the percentage theophylline presumably to be absorbed from the colon 32.3. The corresponding values with normochlorhydria were, respectively, 3.8 h, 8.5 h, and 57.5%. The shorter oral-caecal transit time and lesser upper bowel absorption during normochlorhydria is postulated to result from motilin Release due to duodenal acidification. Gastric hypoacidity resulted in significantly increased cumulative fractions of theophylline absorbed during a 3.5 h period, starting 0.5 h after breakfast. Possibly hypochlorhydria amplifies the increased motility which follows the intake of a meal, resulting in increased peristalsis and antiperistalsis, with more rapid drug absorption.
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The influence of codeine, propantheline and metoclopramide on small bowel transit and theophylline absorption from a Sustained-Release Formulation.
British journal of clinical pharmacology, 1992Co-Authors: D. K. Sommers, J. Moncrieff, E. C. Meyer, M. Van Wyk, Jacques Rene Snyman, R J GrimbeekAbstract:1. The effects of the anticholinergic agent, propantheline, the opiate, codeine, and the prokinetic agent, metoclopramide, on oral-caecal transit time and on the absorption of theophylline from a Sustained-Release Formulation were examined in six healthy male volunteers. 2. A cross-over randomised sequence design was followed, allowing at least 2 weeks interval between studies. On each occasion 500 mg theophylline in a Sustained-Release Formulation was taken simultaneously with 2 g sulphasalazine at zero time. On three of the four occasions one of the following treatments was given concurrently at -0.5 h, +3.5 h, and +7.5 h: 30 mg codeine phosphate, 30 mg propantheline bromide, or 10 mg metoclopramide monohydrochloride. 3. The appearance of sulphapyridine in the plasma was used to assess oral-caecal transit time and the mean fraction absorbed-time profile of theophylline was calculated from serial serum theophylline concentration measurements using the Wagner-Nelson method. 4. Codeine increased the mean (s.d.) oral-caecal time (h) significantly (5.14 +/- 0.94) compared with the control value (3.78 +/- 0.34). Propantheline inhibited peristaltic contractions to such an extent that the oral-caecal transit time in five of the volunteers was between 9 and 25 h, while sulphapyridine appeared in the 9 h serum sample of the sixth. Metoclopramide did not significantly alter the oral-caecal transit time. 5. Despite the observed changes in oral-caecal transit time the rate and extent of theophylline absorption was similar with all regimens.
Amy Peacock - One of the best experts on this subject based on the ideXlab platform.
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opioid use and harms associated with a Sustained Release tapentadol Formulation a post marketing surveillance study
Drug and Alcohol Dependence, 2020Co-Authors: Amy Peacock, Natasa Gisev, Sonja Memedovic, Briony Larance, Jared A Brown, Rose Cairns, Nicholas A Buckley, Michael Farrell, Louisa DegenhardtAbstract:Abstract Aims A Sustained-Release Formulation (SRF) of tapentadol has been marketed in Australia since February 2013. This study examined tapentadol SRF extra-medical use, attractiveness for extra-medical use, and associated harms in Australia. Methods This post-marketing study comprises analyses of Australian community sales data (2011–2017) for eleven pharmaceutical opioids (prescription and over-the-counter codeine disaggregated); calls to three poisons information centres (covering five of the eight jurisdictions in Australia) related to pharmaceutical opioids and coded by the centres as ‘misuse’ or ‘abuse’ (2011–2017); and interviews with people who inject drugs (n = 888) recruited as part of the Illicit Drug Reporting System (IDRS) from all Australian capital cities (2017). Results Population-level availability of tapentadol SRF increased from market launch, comprising the sixth largest market share of all opioid unit sales, and third greatest share in oral morphine equivalent milligrams sold, in December 2017. Lifetime tapentadol SRF use among the IDRS sample (n = 888) was low (1.5%; 95%CI 0.9–2.5), with few reporting past-6 month non-prescribed use or injection. Non-fatal overdose following tapentadol use was self-reported by less than 1% (95%CI 0.1-0.8). Between 2013–2017, 1.1% (n = 25) of pharmaceutical opioid ‘misuse/abuse’ calls were related to tapentadol, and predominantly the SRF. Conclusions Increasing utilisation of tapentadol Sustained-Release Formulation was observed, along with indications of extra-medical use and harms associated with use, although on a smaller scale relative to other opioids. These findings need to be interpreted in the context of the low level of exposure to tapentadol Sustained-Release Formulation among the sentinel population of people who inject drugs.
Heinz Gregor Wieser - One of the best experts on this subject based on the ideXlab platform.
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Comparison of valproate concentrations in human plasma, CSF and brain tissue after administration of different Formulations of valproate or valpromide
Epilepsy research, 1991Co-Authors: Heinz Gregor WieserAbstract:Abstract The concentration of valproate was measured in plasma, CSF and brain tissue of patients who underwent resective surgical treatment because of severe temporal lobe epilepsy after pretreatment with either a Sustained Release Formulation of valproate (Depakine Chrono®; 5 patients), the conventional Formulation of valproate (Depakine®; 6 patients) or valpromide (Depamide®; 2 patients). With a mean serum value for all 13 patients of 32.3 μ/g valproate, the mean brain/serum ratio was 15.1% (SD 6.1%). The valproate concentration of the hippocampus was significantly higher than that of the amygdala and patients who had the Sustained Release Formulation had significantly higher valproate concentration in the CSF and in the hippocampal formation than those patients who had the conventional valproate. Since a few patients had tumors, whereas others had varying degrees of gliosis, it cannot be ruled out that these differences are the result of different histopathological conditions with related differences in blood-brain barrier functions.
Ian R. Wilding - One of the best experts on this subject based on the ideXlab platform.
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Development of a gastric retentive system as a Sustained-Release Formulation of pranlukast hydrate and its subsequent in vivo verification in human studies.
European journal of pharmaceutical sciences : official journal of the European Federation for Pharmaceutical Sciences, 2013Co-Authors: Hikaru Sugihara, Ian R. Wilding, Yuji Matsui, Hirofumi Takeuchi, Alyson Connor, Kazuya Abe, Akio NishiuraAbstract:Pranlukast hydrate was demonstrated in a human site-of-absorption study to have extremely poor absorption properties in the lower gastrointestinal tract. The ratios of AUC0-24 in the distal small bowel and colon compared to stomach delivery were approximately 1/7 and 1/70, respectively. As a consequence, a gastroretentive double-layered tablet Formulation (gastric swelling system; GSS), consisting of a swelling layer and a drug Release layer, was developed for once-daily dosing. To study the gastric retention of the optimized GSS, an in vivo gamma scintigraphic study was carried out in nine healthy volunteers. The transit profiles demonstrated that the GSS was retained in the stomach for more than 10h. The plasma profile was prolonged, especially following administration after an evening meal. The human data validated the design concept and suggest that GSS could be a promising approach for the development of Sustained-Release Formulation for drugs with a limited absorption window in the upper small bowel.
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The effect of food on the gastrointestinal transit and systemic absorption of naproxen from a novel Sustained Release Formulation
Journal of Controlled Release, 1995Co-Authors: C. J. Kenyon, G. Hooper, D. Tierney, J. Butler, John Devane, Ian R. WildingAbstract:Abstract The in vivo behaviour of a novel Sustained Release Formulation of naproxen was investigated using gamma scintigraphy in eight healthy male volunteers under fasted and fed conditions. Disintegration of the tablet into discrete Sustained Release pellets occurred in the stomach shortly after administration. Feeding resulted in a lag time prior to the onset of gastric emptying but food did not affect transit through the small intestine. Post-prandial administration of the Sustained Release Formulation did not affect the disintegration of the tablet or the bioavailability of the drug.
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the effect of food on the in vivo behaviour of a novel Sustained Release Formulation of tiaprofenic acid
International Journal of Pharmaceutics, 1992Co-Authors: Ian R. Wilding, S S Davis, R A Sparrow, J R Bloor, G Hayes, G T WardAbstract:Abstract A novel Sustained Release tablet Formulation of tiaprofenic acid, that has been designed to disintegrate into discrete pellets in the gastrointestinal tract, has been evaluated using a combination of gamma scintigraphy and pharmacokinetics. The performance of the product in vivo was very satisfactory, in that the disintegration of the tableted pellet Formulation was rapid. The gastrointestinal transit behaviour of pellets was affected by food, but food did not affect the subsequent absorption of the Released drug.
