Consumption of a functional fermented milk containing collagen hydrolysate improves the concentration of collagen-specific amino acids in plasma

Clinical studies have shown that collagen hydrolysate (CH) may be able to protect joints from damage, strengthen joints, and reduce pain from conditions like osteoarthritis. CH is a collection of amino acids and bioactive peptides, which allows for easy absorption into the blood stream and distribution in tissues. However, although various matrices have been studied, the absorption of specific amino acids from CH added to a fresh fermented milk product (FMP) was not studied. The primary objective of the present study was to compare the plasma concentrations of four representative amino acids from the CH (glycine, proline, hydroxyproline, and hydroxylysine) contained in a single administration of a FMP with that of a single administration of an equal amount of neat hydrolyzed collagen. These four amino acids were chosen because they have already been used as markers of CH absorption rate and bioavailability. This was a single-center, randomized open, and crossover study with two periods, which was performed in 15 healthy male subjects. The subjects received randomly and in fasted state a single dose of product 1 (10 g of CH in 100 mL of FMP) and product 2 (10 g of CH dissolved in 100 mL of water) separated by at least 5 days. After administration, the subjects were assessed for plasma concentrations of amino acids and for urine concentrations of hydroxyproline. After FMP administration, mean values of the maximal concentration (Cmax) of the four amino acids were greater than after ingredient administration (p < 0.05). This effect was related to an increased Cmax of proline (p < 0.05). In conclusion, because of their physicochemical characteristics, the fermentation process, and the great homogeneity of the preparation, this milk product improves the plasma concentration of amino acids from CH, that is, proline. The present study suggests an interesting role for FMP containing CH to improve the plasmatic availability of collagen-specific amino acids. Hence, this FMP product could be of potential interest in the management of joint diseases.

Continuous infusion of ceftazidime in critically ill patients undergoing continuous venovenous haemodiafiltration: pharmacokinetic evaluation and dose recommendation

Introduction

In seriously infected patients with acute renal failure and who require continuous renal replacement therapy, data on continuous infusion of ceftazidime are lacking. Here we analyzed the pharmacokinetics of ceftazidime administered by continuous infusion in critically ill patients during continuous venovenous haemodiafiltration (CVVHDF) in order to identify the optimal dosage in this setting.

Method

Seven critically ill patients were prospectively enrolled in the study. CVVHDF was performed using a 0.6 m² AN69 high-flux membrane and with blood, dialysate and ultrafiltration flow rates of 150 ml/min, 1 l/hour and 1.5 l/hour, respectively. Based on a predicted haemodiafiltration clearance of 32.5 ml/min, all patients received a 2 g loading dose of ceftazidime, followed by a 3 g/day continuous infusion for 72 hours. Serum samples were collected at 0, 3, 15 and 30 minutes and at 1, 2, 4, 6, 8, 12, 24, 36, 48 and 72 hours; dialysate/ultrafiltrate samples were taken at 2, 8, 12, 24, 36 and 48 hours. Ceftazidime concentrations in serum and dialysate/ultrafiltrate were measured using high-performance liquid chromatography.

Results

The mean (± standard deviation) elimination half-life, volume of distribution, area under the concentration-time curve from time 0 to 72 hours, and total clearance of ceftazidime were 4 ± 1 hours, 19 ± 6 l, 2514 ± 212 mg/h per l, and 62 ± 5 ml/min, respectively. The mean serum ceftazidime steady-state concentration was 33.5 mg/l (range 28.8–36.3 mg/l). CVVHDF effectively removed continuously infused ceftazidime, with a sieving coefficient and haemodiafiltration clearance of 0.81 ± 0.11 and 33.6 ± 4 mg/l, respectively.

Conclusion

We conclude that a dosing regimen of 3 g/day ceftazidime, by continuous infusion, following a 2 g loading dose, results in serum concentrations more than four times the minimum inhibitory concentration for all susceptible pathogens, and we recommend this regimen in critically ill patients undergoing CVVHDF.