Caffeine is an ergogenic substance that is consumed globally in many forms. The use of buccally absorbable formulations instead of gastrointestinal uptake has become increasingly popular over the years, especially when accelerated absorption with minimal gastrointestinal stress is desired. This study investigated the impact of five different formulations and administration routes of caffeine on the whole blood concentrations of caffeine, paraxanthine, and theobromine: caffeinated capsules, tablets, shots, pouches, and chewing gums. A uniform dose of caffeine (200 mg) was administered to 16 healthy recreational athletes (26.0 ± 2.1 years) using a randomized crossover design. Samples were taken in the form of dried blood spots at 16 different time points in a 2-hr timeframe after drug administration. The samples were analyzed using a validated liquid chromatography–tandem mass spectrometry method. The results for caffeine showed no significant differences in the overall bioavailability (area under the concentration–time curve), maximal concentration, and time to maximum concentration. However, when analyzing the bioavailability of caffeine in the first 5, 10, and 15 min, the liquid caffeine formulation was superior to other administered forms (p < .05). This indicates that caffeine solubility has a major influence on its absorption rate. In sports, the rate of caffeine absorption must be considered, not only when ingesting anhydrous caffeine, but also when choosing buccal absorption. These findings imply that general guidelines for ergogenic caffeine use should consider the formulation used and, accordingly, the corresponding route of absorption.

咖啡因是一种强效物质，在全球范围内以多种形式被消费。多年来，使用口腔可吸收制剂代替胃肠道吸收已变得越来越流行，特别是当需要在最小胃肠道压力下加速吸收时。这项研究调查了五种不同的咖啡因配方和给药途径对咖啡因、副黄嘌呤和可可碱全血浓度的影响：含咖啡因的胶囊、片剂、注射剂、袋装和口香糖。采用随机交叉设计，对 16 名健康休闲运动员（26.0 ± 2.1 岁）给予均匀剂量的咖啡因（200 毫克）。在给药后 2 小时内的 16 个不同时间点以干血点的形式采集样本。使用经过验证的液相色谱-串联质谱方法对样品进行分析。咖啡因的结果显示，总体生物利用度（浓度-时间曲线下的面积）、最大浓度和达到最大浓度的时间没有显着差异。然而，在分析前 5 分钟、10 分钟和 15 分钟内咖啡因的生物利用度时，液体咖啡因制剂优于其他给药形式 ( p  < .05)。这表明咖啡因的溶解度对其吸收率有重大影响。在运动中，不仅在摄入无水咖啡因时，而且在选择口腔吸收时，都必须考虑咖啡因的吸收率。这些发现意味着，增强剂咖啡因使用的一般指南应考虑所使用的配方，以及相应的吸收途径。