Preparation and pharmacokinetics in vivo of linarin solid dispersion and liposome / 中草药·英文版

Objective: The current investigation aimed to determine the appropriate dosage form by comparing solid dispersion and liposome to achieve the purpose of improving the solubility and bioavailability of linarin. Methods: Linarin solid dispersion (LSD) and linarin liposome (LL) were developed via the solvent method and the thin film hydration method respectively. The Transwell chamber model of Caco-2 cells was established to evaluate the absorption of drug. The pharmacokinetics of linarin, LSD and LL in rats after ig administration were carried out by high performance liquid chromatography (HPLC) method. Results: The solubility of LSD and LL was severally 3.29 times and 3.09 times than that of linarin. The permeation coefficients of LSD and LL were greater than 10

Evaluation of fluoride bioavailability in toothpastes / 대한구강보건학회지

OBJECTIVES: The aims of this study were to determine the total fluoride concentration and bioavailable fluoride concentration in different toothpastes, based on a newly suggested method by the International Organization for Standardization (ISO), and to compare the measured concentrations with the concentrations written on the packaging. METHODS: The concentrations of total fluoride (TF) and bioavailable fluoride (BF) were measured in six toothpastes. For the TF measurement, 1 g of each toothpaste was mixed with dipotassium hydrogen phosphate (K2HPO4), and hydrogen chloride (HCl) was placed. After 24 hours, the samples were centrifuged and total ionic strength adjustment buffer (TISAB) solution was added. For the BF measurement, the toothpaste was mixed with K2HPO4 for only 1 minute. The samples were centrifuged, and then HCl was placed and allowed to stand for 24 hours. The TISAB solution was added subsequently. The concentration of fluoride ions was measured using a fluoride ion-selective electrode and calculated against a standard curve. RESULTS: The six toothpastes were composed of different fluoride compounds and abrasives. The measured TF concentration ranged from 624.99 ppm to 1,353.00 ppm, and the similarity to the declared fluoride concentration ranged from 53.48% to 93.31%. The measured BF concentration ranged from 587.61 ppm to 1,360.05 ppm, and the similarity to the expected fluoride concentration ranged from 41.97% to 93.80%. Two samples were clearly separated when the samples were centrifuged, whereas the remaining four samples had unclear supernatants. The clearly separated toothpastes (i.e., toothpastes 5 and 6) had BF concentrations that were similar to or lower than the declared fluoride concentrations and the measured TF concentrations. However, the unclearly separated toothpastes showed inconsistent relationships between the measured TF and BF concentrations. CONCLUSIONS: The measured TF and BF concentrations of the six toothpastes did not reach the expected fluoride concentration. This finding resulted from the different compositions and forms of the toothpastes. Therefore, the properties of toothpastes need to be considered when measuring their fluoride concentrations.

Pharmacokinetics and bioavailability of Yufeng Ningxin Tablet in Beagle dog / 中成药

AIM: The plasma concentration-time curve,pharmacokinetic parameters and bioavilability of puerarin,the main active constituent of Yufeng Ningxin Tablets(total flavone of Radix Puerariae Lobatae) in dog by(oral) administration was determined,and the pharmacokinetics was compared with puerarin injection by intravenous injection individually. METHODS: A single dose(the puerarin amount to 10.49 mg/kg) of Yufeng Ningxin Tablets by oral administration and puerarin injection by intravenous injection(9 mg/kg) were given to dogs in a auto-control way. The concentration of puerarin in plasma was determined by HPLC.The PK solutions 2.0 program,a non-compartmental model software,was applied to calculate the pharmacokinetic parameters. RESULTS: 1.The pharmacokinetic parameters of puerarin in dog showed that the t_(1/2E) f puerarin injection(9 mg/kg) by i.v was(72.11)?3.69 min,CL was 4.19?0.25 mL/min,AUC_((0-∞)) was 2172.42?123.02 ?g/min/mL,and the t_(1/2E) of puerarin in Yufeng Ningxin Tablets(10.49 mg/kg) by oral administration was 271.80?7.94 min, CL was 48.52?(2.20) mL/min,C_(max) was 0.43?0.06 ?g/mL, T_(max) was 150 min, AUC_((0-∞)) was 185.77?8.20 ?g/min/mL,and bioavailability was 7.03% compared to puerarin injection by intravenous injection. CONCLUSION: The absorption of puerarin in Yufeng Ningxin Tablets by oral administration comparing with puerarin injection by intravenous injection in dog is very poor,and the bioavailabilites is also low.