Search

Objective: This study aims to show that a proprietary topical cream can deliver glucosamine through the skin into the synovial fluid of osteoarthritic patients. This cream contains 10% w/w glucosamine sulfate. It also aims to determine the endogenous level of glucosamine in the synovial fluid of these patients. Therapeutic effectiveness of glucosamine is not addressed in this study. Design: This phase IV, open-label, nonrandomized study enrolled 240 patients. Participants from the Test group received a single dose treatment (2 g of cream), and synovial fluid samples were collected 1 - 3 hours post-treatment. Patients from the Control group were not subjected to any treatment but their synovial fluid was also sampled to establish a glucosamine concentration baseline for Time-0 (T0). Glucosamine concentrations were determined by HPLC analysis. Results: The mean glucosamine concentration in the synovial fluid of patients from the Test group (100.56 ng/ml, 95% CI 66.36 - 134.76, n = 117) was higher than in the Control group (17.83 ng/ml, 95% CI 7.42 - 28.24, n = 117) resulting in a significant between-group difference (p < 0.0001). While the gender of the subjects did not appear to affect the results, a significant difference was observed with age variation. Conclusion: The results suggest that glucosamine can be topically delivered across the human skin into the synovial fluid using a proper vehicle. This suggests that other water-soluble molecules could similarly be delivered transdermally, alleviating the need for oral delivery in cases where oral administration is difficult, or when harmful side effects could ensue.

Ribavirin is found to be absorbed in the intestine through the human concentrative nucleoside transporter 2 (hCNT2). Cellular uptake of ribavirin was strongly inhibited by purine nucleoside in an in vitro study. This study aims to examine the effects of dietary purine on the pharmacokinetics of orally administered ribavirin in vivo. Twenty healthy participants were enrolled in a randomized, 2-period crossover study. Participants were administered a single 600-mg oral dose of ribavirin after either a high-purine meal or a low-purine meal. Serial blood samples were collected predose and over 144 hours after dosing. Ribavirin concentrations were measured by liquid chromatography/tandem mass spectrometry. In comparison with corresponding plasma values of ribavirin following a high-purine meal, C(max), AUC(0-144) and AUC(0-infinity) of ribavirin following a low-purine meal were 136% (90% confidence internal [CI]: 120%-155%), 134% (90% CI: 118%-153%), and 139% (90% CI: 120%-159%), respectively. This study indicates that dietary purines have an effect on ribavirin absorption. Dosage regimens of ribavirin might need to be adjusted according to the purine content of the meal.