Characteristic hydrolyzing of megalosaccharide by human salivary α-amylase and small intestinal enzymes,and its bioavailability in healthy subjects

The digestibility of Megalosaccharide® (newly developed carbohydrate comprising α-1,4-glucosaccharide) was investigated in vitro and in vivo. Isomaltosyl-megalosaccharide® (IMS) and nigerosyl-megalosaccharide® (NMS) contain 20% and 50% of the megalosaccharide fraction (degree of polymerization (DP) 10–35), respectively. IMS was hydrolyzed readily by α-amylase to oligosaccharides (DP?≤?7), and a small amount of glucose was produced from oligosaccharides by small intestinal enzymes (SIEs). NMS was partially hydrolyzed by α-amylase to oligosaccharides, and a small amount of glucose produced by SIEs. When IMS and NMS were treated by SIEs after treatment with human saliva α-amylase for a few minutes, IMS and NMS were hydrolyzed readily to glucose. Plasma levels of glucose and insulin upon ingestion of 50?g of IMS or NMS were elevated the same as those for 50?g of glucose, and breath hydrogen was not excreted. These results suggest that IMS and NMS are digestible carbohydrates.     

Extension to the use of tolerance intervals for the assessment of individual bioequivalence

For the determination of bioequivalence, researchers have recently shifted their emphasis from average bioequivalence alone to average and individual bioequivalence. Existing methods for assessing average bioequivalence were first developed for the standard 2 × 2 crossover design, but these methods are easily generalized to the two-treatment, ρ-period crossover designs (e.g., TRR, RTT, and TTRR, RRTT, TRRT, RTTR). With respect to individual bioequivalence, Westlake (1,2) implemented the use of parametric and distribution-free tolerance intervals for assessing individual bioequivalence. Anderson and Hauck (3) described what they call the test of individual equivalence ratios (TIER) for the same purpose. Note that these methods have been applied and/or developed only for the standard 2 × 2 crossover design. The present work extends the method of using parametric tolerance intervals for assessing individual bioequivalence.     

The role of particle physico-chemical properties in pulmonary drug delivery for tuberculosis therapy

Abstract

There is increasing interest in the use of inhaled aerosol drug therapy for the treatment of tuberculosis (TB). A number of methods of preparation of particles have been employed including spray drying, solvent evaporation, emulsion and phospholipid methods to create microparticles, macroaggregated nanoparticles, solid lipid nanoparticles and liposomes. Each of these methods involves the use of different proportions of additives to aid in the particle formation or to achieve important physico-chemical properties such as ease of dispersion. While these approaches all have merit their practical value is limited by constraints on dose and means of delivery as an aerosol in order to achieve a therapeutic effect. A review of a number of approaches is presented and placed in the context of the need for effective aerosol delivery systems for the treatment of TB as a guide to selection of appropriate excipients, processes and delivery strategies to support product development activities.     

Improvement of Oral Bioavailability and Anti-Tumor Effect of Zingerone Self-Microemulsion Drug Delivery System

This study sought to prepare a self-microemulsion drug delivery system containing zingerone (Z-SMEDDS) to improve the low oral bioavailability of zingerone and anti-tumor effect. Z-SMEDDS was characterized by particle size, zeta potential and encapsulation efficiency, while its pharmacokinetics and anti-tumor effects were also evaluated. Z-SMEDDS had stable physicochemical properties, including average particle size of 17.29 ± 0.07 nm, the zeta potential of -22.81 ± 0.29 mV, and the encapsulation efficiency of 97.96% ± 0.02%. In vitro release studies have shown the release of zingerone released by Z-SMEDDS was significantly higher than free zingerone in different release media. The relative oral bioavailability of Z-SMEDDS was 7.63 times compared with free drug. Meanwhile, the half inhibitory concentration （IC50）of Z-SMEDDS and free zingerone was 8.45 μg/mL and 13.30 μg/mL, respectively on HepG2. This study may provide a preliminary basis for further clinical research and application of Z-SMEDDS.     

Nasal in-situ gels for delivery of rasagiline mesylate: improvement in bioavailability and brain localization

Abstract

Intranasal thermosensitive gel for rasagiline mesylate (RM) was developed for effective treatment of Parkinson’s disease. Intranasal gels were prepared by combination of poloxamer 407 and poloxamer 188 (1:1) with mucoadhesive polymers (carbopol 934?P and chitosan). The formulations were evaluated for sol–gel transition temperature, in-vitro drug release and in-vivo mucociliary transit time. Further, optimal intranasal gel formulations were tested for in-vivo pharmacokinetic behavior, nasal toxicity studies and brain uptake studies. It was found that optimal formulations had acceptable gelation temperature (28–33?°C) and adequate in-vitro drug release profile. Pharmacokinetic study in rabbits showed significant (p?<?0.05) improvement in bioavailability (four- to six-folds) of the drug from intranasal gels than oral solution. Chronic exposure studies in Wistar rats showed that these intranasal gels were non-irritant and non-toxic to rat nasal mucosa. Estimation of RM in rat brain tissue showed significant (p?<?0.01) improvement in uptake of RM form intranasal gel formulations than nasal solution.     

Self-nanoemulsifying drug delivery system (SNEDDS) of the poorly water-soluble grapefruit flavonoid Naringenin: design,characterization, in vitro and in vivo evaluation

Abstract

Naringenin (NRG), predominant flavanone in grapefruits, possesses anti-inflammatory, anti-carcinogenic, hepato-protective and anti-lipid peroxidation effects. Slow dissolution after oral ingestion due to its poor solubility in water, as well as low bioavailability following oral administration, restricts its therapeutic application. The study is an attempt to improve the solubility and bioavailability of NRG by employing self-nanoemulsifying drug delivery technique. Preliminary screening was carried out to select oil, surfactant and co-surfactant, based on solubilization and emulsification efficiency of the components. Pseudo ternary phase diagrams were constructed to identify the area of nanoemulsification. The developed self-nanoemulsifying drug delivery systems (SNEDDS) were evaluated in term of goluble size, globule size distribution, zeta potential, and surface morphology of nanoemulsions so obtained. The TEM analysis proves that nanoemulsion shows a droplet size less than 50?nm. Freeze thaw cycling and centrifugation studies were carried out to confirm the stability of the developed SNEDDS. In vitro drug release from SNEDDS was significantly higher (p?<?0.005) than pure drug. Furthermore, area under the drug concentration time-curve (AUC_0–24) of NRG from SNEDDS formulation revealed a significant increase (p?<?0.005) in NRG absorption compared to NRG alone. The increase in drug release and bioavailability as compared to drug suspension from SNEDDS formulation may be attributed to the nanosized droplets and enhanced solubility of NRG in the SNEDDS.     

Toxic trace elements at gastrointestinal level

Many trace elements are considered essential [iron (Fe), zinc (Zn), copper (Cu)], whereas others may be harmful [lead (Pb), cadmium (Cd), mercury (Hg), arsenic (As)], depending on their concentration and chemical form. In most cases, the diet is the main pathway by which they enter our organism. The presence of toxic trace elements in food has been known for a long time, and many of the food matrices that carry them have been identified. This has led to the appearance of legislation and recommendations concerning consumption. Given that the main route of exposure is oral, passage through the gastrointestinal tract plays a fundamental role in their entry into the organism, where they exert their toxic effect. Although the digestive system can be considered to be of crucial importance in their toxicity, in most cases we do not know the events that occur during the passage of these elements through the gastrointestinal tract and of ascertaining whether they may have some kind of toxic effect on it. The aim of this review is to summarize available information on this subject, concentrating on the toxic trace elements that are of greatest interest for organizations concerned with food safety and health: Pb, Cd, Hg and As.     

乙酰半胱氨酸颗粒在健康人体的生物等效性研究

目的：建立人血浆乙酰半胱氨酸浓度测定方法,研究乙酰半胱氨酸颗粒在健康人体内的相对生物利用度与生物等效性。方法采用二制剂三周期自身对照完全三交叉试验设计,其中每位受试者有一周期不服药,健康男性受试者24例分别单剂量口服乙酰半胱氨酸受试制剂或参比制剂0.6 g。高效液相色谱串联质谱法测定血浆乙酰半胱氨酸浓度,应用DAS 3.0版统计软件计算药动学参数并评价两种制剂生物等效性。结果单剂量口服乙酰半胱氨酸颗粒受试制剂和参比制剂0.6 g的主要药动学参数：AUC0→t分别为(8547.64±2860.04)和(8783.07±4042.10)μg·h·L-1;AUC0→∞分别为(9481.64±3444.76)和(9540.51±4239.30)μg·h·L-1;Cmax分别为(1994.39±726.42)和(2090.27±885.46)μg·L-1;tmax分别为(1.18±0.60)和(1.13±0.53) h;t1/2分别为(8.60±3.76)和(7.75±5.01) h;相对生物利用度以AUC0→t和AUC0→∞计算分别为(107.0±43.3)％和(106.5±40.1)％。结论乙酰半胱氨酸颗粒两种制剂具有生物等效性。     

Determination and pharmacokinetic study of p-hydroxyphenethyl anisate following intravenous and oral administration in rats by RP-HPLC method

In the present study, we developed a rapid and specific reversed-phase high-performance liquid chromatographic (RP-HPLC) method for the quantification of p-hydroxyphenethyl anisate (HPA), one of the main bioactive constituents of the roots and rhizomes ofNotopterygium incisumand N. franchetii, in rat plasma after an intravenous (20 mg/kg, i.v.) and an intragastrical (200 mg/kg,i.g.) administration to rats, respectively. The method involved a plasma clear-up step using liquid-liquid extraction by EtOAc, followed by RP-HPLC separation and detection. Separation of HPAwas performed on an analytical Diamonsil^TM ODS C₁₈ column with the mobile phase of MeOH–H₂O at ratios of 75:25 (v/v) for i.v. and 70:30 (v/v) for i.g. administration. The flow-rate was 1.0 mL/min, and UV detection was performed at 256 nm. The calibration curves were linear over the ranges of 0.05–5.0 μg/mL (r² = 0.9984) for i.v. and 0.5–10.0 μg/mL (r² = 0.9995) for i.g. administrationin rat plasma. The extraction recoveries were in the range of 82.01%–87.97%. The intra- and inter-day precisions were between 1.71% and 3.99%, with accuracies ranging from 91.22% to 110.5%. The absolute bioavailability of an orally administered HPA in rats was about 48.17%. The developed method was suitable for the determination and pharmacokinetic studyof HPA in rat plasma.