Phosphate Loading Does not Improve 30-km Cycling Time-Trial Performance in Trained Cyclists.

Phosphate is integral to numerous metabolic processes, several of which strongly predict exercise performance (i.e., cardiac function, oxygen transport, and oxidative metabolism). Evidence regarding phosphate loading is limited and equivocal, at least partly because studies have examined sodium phosphate supplements of varied molar mass (e.g., mono/di/tribasic, dodecahydrate), thus delivering highly variable absolute quantities of phosphate. Within a randomized cross-over design and in a single-blind manner, 16 well-trained cyclists (age 38 ± 16 years, mass 74.3 ± 10.8 kg, training 340 ± 171 min/week; mean ± SD) ingested either 3.5 g/day of dibasic sodium phosphate (Na2HPO4: 24.7 mmol/day phosphate; 49.4 mmol/day sodium) or a sodium chloride placebo (NaCl: 49.4 mmol/day sodium and chloride) for 4 days prior to each of two 30-km time trials, separated by a washout interval of 14 days. There was no evidence of any ergogenic benefit associated with phosphate loading. Time to complete the 30-km time trial did not differ following ingestion of sodium phosphate and sodium chloride (3,059 ± 531 s vs. 2,995 ± 467 s). Accordingly, neither absolute mean power output (221 ± 48 W vs. 226 ± 48 W) nor relative mean power output (3.02 ± 0.78 W/kg vs. 3.08 ± 0.71 W/kg) differed meaningfully between the respective intervention and placebo conditions. Measures of cardiovascular strain and ratings of perceived exertion were very closely matched between treatments (i.e., average heart rate 161 ± 11 beats per minute vs. 159 ± 12 beats per minute; Δ2 beats per minute; and ratings of perceived exertion 18 [14-20] units vs. 17 [14-20] units). In conclusion, supplementing with relatively high absolute doses of phosphate (i.e., >10 mmol daily for 4 days) exerted no ergogenic effects on trained cyclists completing 30-km time trials.

Non-destructive, reverse iontophoretic extraction of phytochemicals from Mangifera indica, Centella asiatica, Punica granatum, and Citrus sinensis.

For the commercial-scale isolation of phytochemicals, a suitable plant biomass source (including species, origin, growing season, etc.) must be identified, and frequent analytical verification is required to ensure that the phytochemicals are present at predefined minimum threshold concentrations. While the latter are typically assessed in the laboratory, a more efficient and less resource-intensive approach would involve non-destructive and environmentally friendly measurements in situ. Reverse iontophoretic (RI) sampling offers a potential solution to this challenge. OBJECTIVE: We aimed to demonstrate the non-destructive, RI sampling of phytochemicals of interest from biomass from four different sources. MATERIALS AND METHODS: RI experiments were performed in side-by-side diffusion cells using a current density of 0.5 mA/cm2 , for a predetermined time in a defined pH environment, using (1) fresh leaves from Mangifera indica and Centella asiatica and (2) isolated peel from Punica granatum and Citrus sinensis. RESULTS: Mangiferin, madecassoside, punicalagin, ellagic acid, and hesperidin were extracted from the different biomasses by RI. The amounts extracted ranged from 0.03 mg/100 mg of biomass for the cathodal extraction of madecassoside to 0.63 mg/100 mg of biomass for the anodal extraction of punicalagin. A linear relationship (r2  = 0.73) between the RI-extracted quantities of punicalagin and those determined using conventional methods was demonstrated. CONCLUSION: The non-destructive, in situ measurement of phytochemical levels by RI represents a feasible approach for timing the harvesting process.

Novel beads made of alpha-cyclodextrin and oil for topical delivery of a lipophilic drug.

PURPOSE: To investigate the potential of a novel lipid carrier, comprising beads of alpha-cyclodextrin and soybean oil, for topical drug delivery. Adapalene was chosen as a model drug to explore the ability of the beads to encapsulate and release a highly lipophilic compound. MATERIALS AND METHODS: Adapalene-loaded beads were prepared and characterised. Skin tolerance to unloaded beads was tested on human volunteers, while drug release and delivery into stratum corneum, was evaluated in pig skin ex vivo. RESULTS: The preparation and physical characteristics of the beads were not dependent on whether adapalene had been previously dissolved or dispersed in soybean oil. Drug encapsulation efficiency was high (>96%) and drug loading on the order of a therapeutic level could be achieved in freeze-dried beads prepared from an oily dispersion of adapalene. After application to human skin, unloaded beads induced no adverse reaction and were better tolerated than an alcoholic gel. Tape-stripping the stratum corneum from treated pig skin showed that adapalene release and penetration from the beads was comparable to that from gel and cream formulations available on the market. CONCLUSION: These novel beads may offer a well-tolerated and efficient system for the encapsulation and topical delivery of lipophilic drugs.