Consumption of supplements and energy drinks is common among athletes; however, there is a lack of research on the efficacy of energy drink consumption before and during short-duration, intense exercise. The purpose of this research was to investigate the acute effects of a low-calorie, caffeine-taurine, energy drink (AdvoCare Spark®) on repeated sprint performance and anaerobic power in National Collegiate Athletic Association Division I football players. Twenty well-trained Division I football players (age: 19.7 ± 1.8 years, height: 184.9 ± 5.3 cm, weight: 100.3 ± 21.7 kg) participated in a double-blind, randomized crossover study in which they received the energy drink or an isoenergetic, isovolumetric, noncaffeinated placebo. The two trials were separated by 7 days. The Running Based Anaerobic Sprint Test (RAST), consisting of six 35-m sprints with 10 s of rest between each sprint, was used to assess anaerobic power. Sprint times were recorded with an automatic electronic timer. On average, there iv was no statistically significant difference between the placebo (15.06 ± 3.80 W·s-1) and beverage (15.3 ± 4.18 W·s-1) measurements of fatigue index. Neither were there statistically significant main effects of the beverage treatment on power F(1, 18) = 3.84, p = 0.066; or sprint time F(1, 18) = 3.06, p = 0.097. However, there was a significant interaction effect between caffeine use and the beverage for sprint times (F = 4.62, p = 0.045), as well as for anaerobic power (F = 5.40, p = 0.032), indicating a confounding effect. In conclusion, a caffeine-taurine energy drink did not improve the sprint performance or the anaerobic power of collegiate football players, but the level of caffeine use by the athletes likely influenced the effect of the drink.

<p> </p><p><strong><em> </em></strong></p><p><strong><em> </em></strong></p><p><strong><em> </em></strong></p><p><strong><em> </em></strong></p><p><strong>Construction of a laboratory lesson for upper secondary school in the area of Liquid Chromatography, including carrying through the laboratory lesson in a class</strong></p><p><strong> </strong></p><p>Laboratory lessons constitute an important part of science education. There are different sorts of laboratory lessons. In some laboratory lessons the students themselves are active, and in others the teacher demonstrates an experiment for the students. Some laborative work can be defined by the teacher while other can give the students an opportunity to plan an investigation themselves.</p><p> </p><p>A new laboratory lesson, on the area of Liquid Chromatography, for upper secondary school has been made. In the laboratory lesson chocolate is analysed regarding the content of caffeine and theobromine. The laboratory lesson has been carried out in a class, to see what the students know about solubility, dilution, chromatography and analytical procedure after they have gone through the laboratory lesson. To get information about the students knowledge a questionnaire study was done. Teachers also have been interviewed, for their opinion about laboratory lessons as a part of science education.</p><p> </p><p>All students showed some knowledge about solubility, and most students also had knowledge about chromatography even if they described different aspects of it. Dilutions was not a problem for most of the students. Many students also showed an understanding of the analytical procedure. For the teachers interviewed laborative work was an important part of science education.</p><p> </p><p><strong>Key words:</strong> Liquid chromatography, laboratory lesson, upper secondary school, chocolate, theobromine, caffeine, questionnaire study, and interviews.</p><p> </p><p> </p><p>Advisor:  <strong>Margareta Sandahl, </strong>Lund University</p><p><strong>Olle Eskilsson, </strong>Kristianstad University</p><p>Degree project 30 credits in Chemistry/Educational Science 2008/2009</p><p>Department of Chemistry, Lund University</p><p>School of Teacher Education, Kristianstad University</p>

Construction of a laboratory lesson for upper secondary school in the area of Liquid Chromatography, including carrying through the laboratory lesson in a class Laboratory lessons constitute an important part of science education. There are different sorts of laboratory lessons. In some laboratory lessons the students themselves are active, and in others the teacher demonstrates an experiment for the students. Some laborative work can be defined by the teacher while other can give the students an opportunity to plan an investigation themselves.   A new laboratory lesson, on the area of Liquid Chromatography, for upper secondary school has been made. In the laboratory lesson chocolate is analysed regarding the content of caffeine and theobromine. The laboratory lesson has been carried out in a class, to see what the students know about solubility, dilution, chromatography and analytical procedure after they have gone through the laboratory lesson. To get information about the students knowledge a questionnaire study was done. Teachers also have been interviewed, for their opinion about laboratory lessons as a part of science education.   All students showed some knowledge about solubility, and most students also had knowledge about chromatography even if they described different aspects of it. Dilutions was not a problem for most of the students. Many students also showed an understanding of the analytical procedure. For the teachers interviewed laborative work was an important part of science education.   Key words: Liquid chromatography, laboratory lesson, upper secondary school, chocolate, theobromine, caffeine, questionnaire study, and interviews.     Advisor:  Margareta Sandahl, Lund University Olle Eskilsson, Kristianstad University Degree project 30 credits in Chemistry/Educational Science 2008/2009 Department of Chemistry, Lund University School of Teacher Education, Kristianstad University

Caffeine is a commercially important member of a group of purine alkaloids found in coffee, tea and cacao particularly. It is an important ingredient in beverages and most important chemical element of stimulating pharmaceuticals. Caffeine is either manufactured by total synthesis or as a by-product from the decaffeinated coffee manufacturing. To investigate the equilibrium relationship of caffeine in ion exchange systems, which are widely used for recovery and purification processes, was the aim of this study. The effects of initial caffeine concentration and pH of the solution on equilibrium were also investigated. Stock solutions of caffeine were prepared for screening of available adsorbents and cation exchange resins. A batch type operation was carried out in a shaker bath at 40 oC with 200 rpm agitation rate. After preliminary experiments, only Lewatit S100, which is a strongly acidic cation exchange resin with s-dvb copolymer matrix, was studied. For the analysis of samples, HPLC equipment with Shimadzu PDA Detector at 254 nm and Nucleosil 100 C18 column was used. As mobile phase, a mixture of 8% acetonitrile, 8% 2-Propanol, and 1% acetic acid was introduced at 1.5 mL/min flow rate. Results showed that, the caffeine uptake capacity of cation exchange resin was poor. A set of experiments were performed at three initial concentrations (0.005 M, 0.0075 M, and 0.01 M) and four different pH regions (acidic, slightly acidic, neutral, and basic). It was found that, at extreme pH conditions, the caffeine loading capacity of the resin was slightly increased. A significant effect of initial caffeine concentration, however, couldn&rsquo / t be observed. Due to the poor performance of gel type cation exchange resin and large molecular structure of caffeine molecule, Lewatit&rsquo / s SPC 112 macroporous resin was studied briefly for caffeine uptake performance. It was observed that SPC 112 has also poor but better loading capacity than S100 cation exchange resin.

Pharmaceutical cocrystals use principles of crystal engineering for the design of crystalline forms of drugs and can improve their solubility, bioavailability, stability and other important properties without changing the efficacy of the drug. Herein reported are pharmaceutical cocrystals of two API's, caffeine and Pentoxifylline. Research has indicated that caffeine has the ability to reverse AB; plaque deposition in the brain (believed to be the primary cause of Alzheimer's pathogenesis) and thus revert memory and improve cognitive impairment. But owing to the fast absorption rate and short half life, a controlled release formulation of caffeine would be clinically beneficial. Thus, novel cocrystals of caffeine are presented with varying solubilities with respect to caffeine. The pharmaceutical cocrystals of caffeine used herein include: caffeine.cyanuric acid monohydrate, caffeine.syringic acid tetrahydrate, caffeine.chlorogenic acid and caffeine.catechin hydrate. Three caffeine cocrystals were prepared in our lab previously which include caffeine.ferulic acid, caffeine.ethyl gallate dihydrate and caffeine.caffeic acid. In addition, six caffeine cocrystal forms were reproduced from the literature and included in the solubility study: caffeine.quercetin, caffeine.salicylic acid, caffeine.1-hydroxy-2-napthoic acid, caffeine.gallic acid hemihydrate, caffeine.ellagic acid monohydrate and caffeine.coumaric acid. Dissolution studies were performed in aqueous media at room temperature. All of the cocrystals decreased the solubility of caffeine with the highest being a 278 fold decrease in the solubility of caffeine. Analysis of melting point, crystal packing efficiency and solubility of cocrystal former with solubility was also done to determine if they influenced the solubility. Presented herein are the results of the analyses. It was seen that solubility of the cocrystal former had no effect on the decrease in cocrystal solubility. Moreover melting point and solubility of the cocrystal could not be correlated probably due to the variability in the cocrystal formers. Crystal packing efficiency though did not show a high correlation with solubility but it was seen that highest solubility achieved by pure caffeine achieved the lowest crystal packing efficiency and vice versa suggesting its role in cocrystal solubility. Pentoxifylline is contraindicated for its use in autism. But owing to high solubility of the drug, a less soluble form of the drug would help in decreasing the half life and thereby help in forming a sustained form of the drug by modifying the inherent solubility of the API. Here, novel cocrystals of Pentoxifylline are presented with varying solubilities with respect to the API. The pharmaceutical cocrystals used herein include: pentoxifylline.benzoic acid, pentoxifylline.1-hydroxy-2-napthoic acid, pentoxifylline.salicylic acid, pentoxifylline.gallic acid, pentoxifylline. salicylamide, pentoxifylline.coumaric acid, pentoxifylline.caffeic acid and pentoxifylline.catechin hydrate. Dissolution studies were also performed in aqueous media at room temperature. All of the cocrystals decreased the solubility of Pentoxifylline with the highest being a 99 fold decrease in the solubility with pentoxifylline.coumaric acid. On analyzing melting point, crystal packing efficiency and relation of solubility of cocrystal former with solubility of cocrystal, as was done in the case of caffeine, the parameters showed no effect on solubility of the cocrystal.

Dispersing co-crystals in a polymeric carrier may improve their physicochemical properties such as dissolution rate and solubility. Additionally co-crystal stability may be enhanced. However, such dispersions have been little investigated to date. This study focuses on the feasibility of dispersing co-crystals in a polymeric carrier and theoretical calculations to predict their stability. Acetone/chloroform, ethanol/water, and acetonitrile were used to load and grow co-crystals in a HPMCAS film. Caffeine-malonic acid and ibuprofennicotinamide co-crystals were prepared using solvent evaporation method. The interactions between each of the co-crystals components and their mixtures with the polymer were studied. A solvent evaporation approach was used to incorporate each compound, a mixture, and co-crystals into HPMCAS films. Differential scanning calorimetry data revealed a higher affinity of the polymer to acidic compounds than their basic counterparts as noticed by the depression of the glass transition temperature (Tg). Moreover, the same drug loading produced films with different Tgs when different solvents were used. Solubility parameter values (SP) of the solvents were employed to predict that effect on the depression of polymer Tg with relative success. SP values were more successful in predicting the preferential affinity of two acidic compounds to interact with the polymer. This was confirmed using binary mixtures of naproxen, flurbiprofen, malonic acid, and ibuprofen. On the other hand, dispersing basic compounds such as caffeine or nicotinamide with malonic acid in HPMCAS film revealed the growth of co-crystals. A dissolution study showed that the average release of caffeine from films containing caffeine-malonic acid was not significantly different to that of films containing similar caffeine concentration. The stability of the caffeine-malonic acid co-crystals in HPMC-AS was prolonged to 8 weeks at 95% relative humidity and 45°C. The theory developed in this project, that an acidic drug with a SP value closer to the polymer will dominate the interaction process and prevent the majority of the other material from interacting with the polymer, may have utility in designing co-crystal systems in polymeric vehicles

BACKGROUND: Exercise is a critical treatment modality in persons with Type II Diabetes Mellitus (T2DM), however people with this disease experience chronic fatigue and a decreased exercise capacity, which affects their ability or willingness to participate in physical activity. Studies suggest that this exercise intolerance may be partly due to a reduced exercising muscle blood flow (MBF), and in particular to a reduced ability of red blood cells (RBCs) to evoke ATP-mediated vasodilation and an increase in MBF as they traverse areas of high O2 demand. Additional evidence suggests that caffeine may attenuate this impairment by enhancing the release of ATP from RBCs. HYPOTHESIS: Persons with T2DM would have reduced Forearm Blood Flow (FBF), oxygen consumption (VO2), and exercise tolerance responses to exercise compared to control (CON) subjects, and caffeine would attenuate these impairments. METHODS: T2DM (n = 4) and CON (n = 4) participants performed rhythmic forearm handgrip exercise at an intensity equivalent to 17.5 kg until “task failure” or 20 minutes of exercise was reached, after having consumed either a caffeine (5mg/kg; Caff) or placebo (Pl) capsule. FBF (Doppler and Echo ultrasound of the brachial artery), VO2 and lactate efflux (deep venous blood sampling), forearm vascular conductance (FVK), mean arterial pressure (MAP) and heart rate (HR) were quantified for each minute of exercise. RESULTS: Steady state FBF was similar across groups and treatment conditions (mean ± SE ml/min; CONCaff 553.80 ± 82.35, CONPl 583.42 ± 112.62, T2DMCaff 523.33 ± 105.39, T2DMPl 569.08 ± 134.20, NS), and this was due to similar MAP and FVK (across groups and treatment conditions, NS). VO2 and Time to Task Failure (TTF) were not different between groups and treatment conditions (NS), although TTF tended to be improved with caffeine versus placebo (10.00 ± 2.02 vs 8.24 ± 1.79 min, P=0.295). There was a strong positive relationship between FBF and TTF (r2=0.763; P=0.005). CONCLUSIONS: In the exercise model utilized, persons with T2DM do not have impaired cardiovascular responsiveness or reduced exercise tolerance, and caffeine does not provide any benefit. Differences in exercising MBF may be an underlying mechanism regarding differences in exercise tolerance. / Thesis (Master, Kinesiology & Health Studies) -- Queen's University, 2009-09-16 16:19:42.537

No description available.

The purpose of this research study was to examine the effects of consumption of beverages (caffeinated and alcoholic) and physical activity on the frequency and severity of hot flashes in peri-menopausal, menopausal, and post-menopausal women by conducting an on-line survey of women over the age of 40 employed at a Midwestern University. One-hundred ninety-six women participated in this study. Majority of participants were age 50-59 (n=104, 53.1%), and were in the naturally post-menopausal reproductive stage (n=81, 41.3%). Overall, results revealed that the effects of self-reported physical activity, average daily caffeine and alcohol intake were not significant in predicting the frequency of hot flashes (R2=.043, F(6, 184) = 1.39, p= .221). However, results revealed a small, but statistically significant effect of physical activity, caffeine, and alcohol intake on severity of hot flashes (R2=.068, F(6,180) = 2.195, p = .046). Additionally, relatively more participation in aerobic physical activity increased frequency of hot flashes (p= .031); while higher intensity of aerobic physical activity had an inverse relationship on both frequency and severity of hot flashes (p=.011, p=.003, respectively). / Department of Family and Consumer Sciences

The purpose of this study was to investigate the effects of: 1) caffeine consumption; 2) Body Mass Index (BMI); and 3) frequency and intensity of physical activity on the frequency and severity of hot flashes, in pre-menopausal, peri-menopausal, menopausal and post-menopausal Hispanic women. Ordinary Least Squares regressions indicated there was a statistical significant correlation between daily total estimated caffeine intake with frequency (R2=0.078 (F(8, 207)=2.2, P=0.029) and severity of hot flashes (R2=0.086 (F(8, 208)=2.45, P=0.015). Analysis of variance revealed that and increase in frequency of 30 min strength physical activity reduced severity of hot flashes by 0.72 on a hedonic scale (p<0.05). Conversely, caffeine intake of 100 mg increased frequency and severity of hot flashes (p<0.001, p=0.004, respectively). / Department of Family and Consumer Sciences