Speciation of Phosphorus in Pet Foods by Solid-State 31P-MAS-NMR Spectroscopy.

Solid-state magic angle spinning 31P NMR spectroscopy is used to identify and quantify phosphorus-containing species in pet foods. The measurement is challenging due to the long spin-lattice relaxation times (T1s). Data acquisition times are shortened by acquiring data with a tip angle smaller than 90° and shortening the repetition time. However, the spin-lattice relaxation times (T1s) of the different 31P compounds are quite different, necessitating a separate measurement for each compound in the pet food. Knowledge of T1 is used to calculate the relative amount of 31P in the samples. Samples of known concentration are also measured, enabling the quantitative measurement of total phosphorus content.

A Randomized, Two-Way Crossover Study to Evaluate the Pharmacokinetics of Caffeine Delivered Using Caffeinated Chewing Gum Versus a Marketed Caffeinated Beverage in Healthy Adult Volunteers.

Background: This study was conducted to compare the pharmacokinetics of caffeine delivered using caffeinated chewing gum to that delivered using a marketed caffeinated beverage (instant coffee) in 16 healthy adult volunteers. Materials and Methods: This was a controlled open-label, randomized, two-period crossover study. Caffeinated chewing gum and a serving of instant coffee, each containing ∼50 mg caffeine, were administered with blood samples collected before and up to 24 hours after administration starts. Plasma caffeine levels were analyzed using validated liquid chromatography coupled with tandem mass spectrometry methodology. Results: There were no statistical differences between the two caffeine products in tmax (p = 0.3308) and ka (p = 0.3894). Although formulated at ∼50 mg caffeine each, mean dose released from chewing gum was ∼18% less than beverage. Dose-normalized area under the concentration-time curve (AUC)0-t, AUC0-∞, and Cmax was similar between products. Although the criteria were not set a priori and the study was not powered for concluding bioequivalence, the 90% confidence intervals fell within the bioequivalence limit of 80% to 125%. Conclusions: Existing scientific literature on caffeine, based mostly on data from caffeinated beverages, can be leveraged to support the safety of caffeine delivered by chewing gum and current maximum safe caffeine dose advice should be applicable irrespective of delivery method.