168 research outputs found
Prevention of Rat Intestinal Injury with a Drug Combination of Melatonin and Misoprostol
A healthy intestinal barrier prevents uptake of allergens and toxins, whereas intestinal permeability increases following chemotherapy and in many gastrointestinal and systemic diseases and disorders. Currently, there are no approved drugs that target and repair the intestinal epithelial barrier while there is a medical need for such treatment in gastrointestinal and related conditions. The objective of this single-pass intestinal perfusion study in rats was to investigate the preventive cytoprotective effect of three mucosal protective drugs¿melatonin, misoprostol, and teduglutide¿with different mechanisms of action on an acute jejunal injury induced by exposing the intestine for 15 min to the anionic surfactant, sodium dodecyl sulfate (SDS). The effect was evaluated by monitoring intestinal clearance of 51Cr-labeled ethylenediaminetetraacetate and intestinal histology before, during, and after luminal exposure to SDS. Our results showed that separate pharmacological pretreatments with luminal misoprostol and melatonin reduced acute SDS-induced intestinal injury by 47% and 58%, respectively, while their use in combination abolished this injury. This data supports further development of drug combinations for oral treatments of conditions and disorders related to a dysregulated or compromised mucosal epithelial barrier
Improved Cortisol Exposure-Time Profile and Outcome in Patients with Adrenal Insufficiency: A Prospective Randomized Trial of a Novel Hydrocortisone Dual-Release Formulation.
Context:Patients with treated adrenal insufficiency (AI) have increased morbidity and mortality rate. Our goal was to improve outcome by developing a once-daily (OD) oral hydrocortisone dual-release tablet with a more physiological exposure-time cortisol profile.Objective:The aim was to compare pharmacokinetics and metabolic outcome between OD and the same daily dose of thrice-daily (TID) dose of conventional hydrocortisone tablets.Design and Setting:We conducted an open, randomized, two-period, 12-wk crossover multicenter trial with a 24-wk extension at five university hospital centers.Patients:The trial enrolled 64 adults with primary AI; 11 had concomitant diabetes mellitus (DM).Intervention:The same daily dose of hydrocortisone was administered as OD dual-release or TID.Main Outcome Measure:We evaluated cortisol pharmacokinetics.Results:Compared with conventional TID, OD provided a sustained serum cortisol profile 0-4 h after the morning intake and reduced the late afternoon and the 24-h cortisol exposure. The mean weight (difference = -0.7 kg, P = 0.005), systolic blood pressure (difference = -5.5 mm Hg, P = 0.0001) and diastolic blood pressure (difference: -2.3 mm Hg; P = 0.03), and glycated hemoglobin (absolute difference = -0.1%, P = 0.0006) were all reduced after OD compared with TID at 12 wk. Compared with TID, a reduction in glycated hemoglobin by 0.6% was observed in patients with concomitant DM during OD (P = 0.004).Conclusion:The OD dual-release tablet provided a more circadian-based serum cortisol profile. Reduced body weight, reduced blood pressure, and improved glucose metabolism were observed during OD treatment. In particular, glucose metabolism improved in patients with concomitant DM
Food selection associated with sense of coherence in adults
BACKGROUND: Favorable dietary habits promote health, whereas unfavorable habits link to various chronic diseases. An individual's "sense of coherence" (SOC) is reported to correlate with prevalence of some diseases to which dietary habits are linked. However, understanding what determines an individual's dietary preferences and how to change his/her behavior remains limited. The aim of the present study was to evaluate associations between dietary intake and SOC in adults. METHODS: Diet intake was recorded by an 84-item semi-quantitative food frequency questionnaire and SOC was measured by the 13-item Antonovsky questionnaire in 2,446 men and 2,545 women (25–74 years old) from the population based northern Sweden MONICA screening in 1999. RESULTS: Intakes of energy, total and saturated fat, ascorbic acid, sucrose, and servings of fruits, vegetables, cereals, and sweets correlated with SOC among women, whereas intakes of total and saturated fat, ascorbic acid, fiber, and alcohol, and servings of fruits, vegetables, bread, bread and cereals, fish, and potatoes correlated with SOC among men. With a few exceptions, intakes of these nutrients/foods were significantly explained by SOC quartile scores in linear GLM models. Both women and men classified into the highest SOC quartile had significantly higher age-BMI-education standardized mean intakes of vegetables than those in the lowest quartiles. Women in the highest SOC quartile also had higher intake of fruits but lower intakes of energy, total and saturated fat, sucrose, and sweets. Projection to latent structures (PLS) multivariate modeling of intakes of the 84 food items and food aggregates simultaneously on SOC scores supported low SOC to coincide with a presumably less health promoting dietary preference, e.g. intake of pizza, soft drinks, candies, sausages for main course, hamburgers, mashed potato, chips and other snacks, potato salad, French fries, whereas men and women with high SOC scores were characterized by e.g. high intake of rye crisp whole meal bread, boiled potato, vegetables, berries, and fruits. CONCLUSION: Both men and women in the highest, as compared with the lowest, SOC score quartile reported more "healthy" food choices. Dietary habits for individuals in the lowest SOC quartile therefore may render a higher risk for various endemic diseases
Human Jejunal Permeability of Two Polar Drugs: Cimetidine and Ranitidine
Purpose . To determine the human jejunal permeability of cimetidine and ranitidine using a regional jejunal perfusion approach, and to integrate such determinations with previous efforts to establish a baseline correlation between permeability and fraction dose absorbed in humans for soluble drugs.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41484/1/11095_2004_Article_302739.pd
Celiprolol double-peak occurrence and gastric motility: Nonlinear mixed effects modeling of bioavailability data obtained in dogs
Investigation of the underlying mechanism leading to inter- and intrasubject variations in the plasma concentration-time profiles of drugs (1) can considerably benefit rational drug therapy. The significant effect of gastric emptying on the rate and extent of celiprolol absorption and its role with respect to double-peak formation was demonstrated in the present study. In four dogs racemic celiprolol was dosed perorally in a crossover design during four different phases of the fasted-state gastric cycle and gastric motility was recorded simultaneously using a manometric measurement system. Intravenous doses were also given to obtain disposition and bioavailability parameters. The blood samples were assayed by a stereoselective HPLC method (2). The time to onset of the active phase of the gastric cycle showed an excellent correlation with the time to celiprolol peak concentration. Furthermore, bioavailability was increased when celiprolol was administered during the active phase. Double peaks were observed when the first active phase was relatively short, suggesting that a portion of the drug remained in the stomach until the next active phase. Population pharmacokinetic modeling of the data with a two-compartment open model with two lag times incorporating the motility data confirmed the effect of time to gastric empyting on the variability of the oral pharmacokinetics of celiprolol. The fasted-state motility phases determine the rate and extent of celiprolol absorption and influence the occurrence of double peaks. Peak plasma levels of celiprolol exhibit less variability if lag times, and therefore gastric emptying times, are taken into consideration.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45049/1/10928_2006_Article_BF02354285.pd
Computational approaches for modeling human intestinal absorption and permeability
Human intestinal absorption (HIA) is an important roadblock in the formulation of new drug substances. Computational models are needed for the rapid estimation of this property. The measurements are determined via in vivo experiments or in vitro permeability studies. We present several computational models that are able to predict the absorption of drugs by the human intestine and the permeability through human Caco-2 cells. The training and prediction sets were derived from literature sources and carefully examined to eliminate compounds that are actively transported. We compare our results to models derived by other methods and find that the statistical quality is similar. We believe that models derived from both sources of experimental data would provide greater consistency in predictions. The performance of several QSPR models that we investigated to predict outside the training set for either experimental property clearly indicates that caution should be exercised while applying any of the models for quantitative predictions. However, we are able to show that the qualitative predictions can be obtained with close to a 70% success rate
Five meal patterns are differently associated with nutrient intakes, lifestyle factors and energy misreporting in a sub-sample of the Malmö Diet and Cancer cohort
OBJECTIVE: Examine how meal patterns are associated with nutrient intakes, lifestyle and socioeconomic factors, and energy misreporting. DESIGN: A cross-sectional study within the Malmö Diet and Cancer (MDC) cohort. Participants reported on the overall types and frequency of meals consumed, and completed a modified dietary history, a lifestyle and socioeconomic questionnaire, and anthropometric measurements. Based on the reported intake of six different meal types, meal pattern groups were distinguished using Ward's cluster analysis. Associations between meal patterns and nutrient intakes, anthropometric, lifestyle and socioeconomic variables were examined using the chi(2)-method and analysis of variance. SUBJECTS: A sub-sample of the MDC study cohort (n=28,098), consisting of 1,355 men and 1,654 women. RESULTS: Cluster analysis identified five groups of subjects with different meal patterns in both men and women. These meal pattern groups differed regarding nutrient intakes, lifestyle and socioeconomic factors. Subjects reporting frequent coffee meals were more likely to report an 'unhealthy' lifestyle, e.g. smoking, high alcohol consumption and low physical activity, while those with a fruit pattern reported a more 'healthy' lifestyle. Women were more likely to underreport their energy intake than men, and the degree of underreporting varied between the meal pattern groups. CONCLUSIONS: The meal pattern groups showed significant differences in dietary quality and socioeconomic and lifestyle variables. This supports previous research suggesting that diet is part of a multifaceted phenomenon. Incorporation of aspects on how foods are combined and eaten into public health advices might improve their efficiency
Equilibrium solubility versus intrinsic dissolution: characterization of lamivudine, stavudine and zidovudine for BCS classification
Solubility and dissolution rate of drugs are of major importance in pre-formulation studies of pharmaceutical dosage forms. The solubility improvement allows the drugs to be potential biowaiver candidates and may be a good way to develop more dose-efficient formulations. Solubility behaviour of lamivudine, stavudine and zidovudine in individual solvents (under pH range of 1.2 to 7.5) was studied by equilibrium solubility and intrinsic dissolution methods. In solubility study by equilibrium method (shake-flask technique), known amounts of drug were added in each media until to reach saturation and the mixture was subjected to agitation of 150 rpm for 72 hours at 37 ºC. In intrinsic dissolution test, known amount of each drug was compressed in the matrix of Wood's apparatus and subjected to dissolution in each media with agitation of 50 rpm at 37 ºC. In solubility by equilibrium method, lamivudine and zidovudine can be considered as highly soluble drugs. Although stavudine present high solubility in pH 4.5, 6.8, 7.5 and water, the solubility determination in pH 1.2 was not possible due stability problems. Regarding to intrinsic dissolution, lamivudine and stavudine present high speed of dissolution. Considering a boundary value presented by Yu and colleagues (2004), all drugs studied present high solubility characteristics in intrinsic dissolution method. Based on the obtained results, intrinsic dissolution seems to be superior for solubility studies as an alternative method for biopharmaceutical classification purposes
The Role of Transporters in the Pharmacokinetics of Orally Administered Drugs
Drug transporters are recognized as key players in the processes of drug absorption, distribution, metabolism, and elimination. The localization of uptake and efflux transporters in organs responsible for drug biotransformation and excretion gives transporter proteins a unique gatekeeper function in controlling drug access to metabolizing enzymes and excretory pathways. This review seeks to discuss the influence intestinal and hepatic drug transporters have on pharmacokinetic parameters, including bioavailability, exposure, clearance, volume of distribution, and half-life, for orally dosed drugs. This review also describes in detail the Biopharmaceutics Drug Disposition Classification System (BDDCS) and explains how many of the effects drug transporters exert on oral drug pharmacokinetic parameters can be predicted by this classification scheme
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