Quercetin-Containing Self-Nanoemulsifying Drug Delivery System for Improving Oral Bioavailability

Quercetin is a dietary flavonoid with potential chemoprotective effects, but has low bioavailability because of poor aqueous solubility and low intestinal absorption. A quercetin-containing self-nanoemulsifying drug delivery system (Q-SNEDDS) was developed to form oil-in-water nanoemulsions in situ for improving quercetin oral bioavailability. On the basis of the quercetin solubility, emulsifying ability, and stability after dispersion in an aqueous phase, an optimal SNEDDS consisting of castor oil, Tween® 80, Cremophor® RH 40, and PEG 400 (20:16:34:30, w/w) was identified. Upon mixing with water, Q-SNEDDS formed a nanoemulsion having a droplet size of 208.8 ± 4.5 nm and zeta potential of −26.3 ± 1.2 mV. The presence of Tween® 80 and PEG 400 increased quercetin solubility and maintained supersaturated quercetin concentrations (5 mg/mL) for >1 month. The optimized Q-SNEDDS significantly improved quercetin transport across a human colon carcinoma (Caco-2) cell monolayer. Fluorescence imaging demonstrated rapid absorption of the Q-SNEDDS within 40 min of oral ingestion. Following oral administration of Q-SNEDDS in rats (15 mg/kg), the area under the concentration curve and maximum concentration of plasma quercetin after 24 h increased by approximately twofold and threefold compared with the quercetin control suspension. These data suggest that this Q-SNEDDS formulation can enhance the solubility and oral bioavailability of quercetin for appropriate clinical application.     

Supersaturated Self-Nanoemulsifying Drug Delivery Systems (Super-SNEDDS) Enhance the Bioavailability of the Poorly Water-Soluble Drug Simvastatin in Dogs

This study investigates the potential of supersaturated self-nanoemulsifying drug delivery systems (super-SNEDDS) to improve the bioavailability of poorly water-soluble drugs compared to conventional SNEDDS. Conventional SNEDDS contained simvastatin (SIM) at 75% of the equilibrium solubility (S_eq). Super-SNEDDS containing SIM at 150 and 200% of S_eq were produced by subjecting the SNEDDS preconcentrates to a heating and cooling cycle. The super-SNEDDS were physically stable over 10 months. During in vitro lipolysis of SNEDDS and super-SNEDDS the SIM concentration in the aqueous phase increased for the first 30 min almost proportional to the drug loads and amounts of preconcentrate employed. The 200% drug-loaded super-SNEDDS generated an amorphous SIM precipitate at the end of in vitro lipolysis. In vivo, the relative bioavailability of SIM from super-SEDDDS increased significantly to 180 ± 53.3% (p = 0.014) compared to the dosing of two capsules of (dose equivalent) 75% drug-loaded SNEDDS. A significant increase in the terminal half-life of elimination was observed for super-SNEDDS (2.3 ± 0.6 h) compared to conventional SNEDDS (1.4 ± 0.3 h) as well as a decreased area under the curve ratio of the SIM metabolite simvastatin acid to the parent compound (0.57 ± 0.20 and 0.90 ± 0.3), possibly due to a combination of saturation effects on presystemic metabolising enzymes and prolonged absorption along the small intestine. In summary, this study demonstrated that super-SNEDDS are a viable formulation option to enhance the bioavailability of poorly water-soluble drugs such as simvastatin while reducing the pill burden by an increased drug load of SNEDDS.Key words: bioavailability, in vitro digestion, in vitro lipolysis, simvastatin, supersaturated self-nanoemusifying drug delivery systems (super-SNEDDS) poorly soluble drugs     

Self-Nanoemulsifying Drug Delivery System of Lutein: Physicochemical Properties and Effect on Bioavailability of Warfarin

Objective of present study was to prepare and characterize self-nanoemulsifying drug delivery system (SNEDDS) of lutein and to evaluate its effect on bioavailability of warfarin. The SNEDDS was prepared using an oil, a surfactant, and co-surfactants with optimal composition based on pseudo-ternary phase diagram. Effect of the SNEDDS on the bioavailability of warfarin was performed using Sprague Dawley rats. Lutein was successfully formulated as SNEDDS for immediate self-emulsification and dissolution by using combination of Peceol as oil, Labrasol as surfactant, and Transcutol-HP or Lutrol-E400 as co-surfactant. Almost complete dissolution was achieved after 15 min while lutein was not detectable from the lutein powder or intra-capsule content of a commercial formulation. SNEDDS formulation of lutein affected bioavailability of warfarin, showing about 10% increase in C_max and AUC of the drug in rats while lutein as non-SNEDDS did not alter these parameters. Although exact mechanism is not yet elucidated, it appears that surfactant and co-surfactant used for SNEDDS formulation caused disturbance in the anatomy of small intestinal microvilli, leading to permeability change of the mucosal membrane. Based on this finding, it is suggested that drugs with narrow therapeutic range such as warfarin be administered with caution to avoid undesirable drug interaction due to large amount of surfactants contained in SNEDDS.     

Improved Oral Bioavailability of BCS Class 2 Compounds by Self Nano-Emulsifying Drug Delivery Systems (SNEDDS): The Underlying Mechanisms for Amiodarone and Talinolol

Pharmaceutical Research - Superior bioavailability of BCS Class 2 compounds incorporated into SNEDDS was previously reported. This study aims to elucidate the underlying mechanisms accountable for...     

A Self-Nanoemulsifying Drug Delivery System for Enhancing the Oral Bioavailability of Candesartan Cilexetil: Ex Vivo and In Vivo Evaluation

The drug delivery of candesartan cilexetil encounters an obstacle of low absolute oral bioavailability which is attributed mainly to its low aqueous solubility and efflux by intestinal P-glycoprotein (P-gp) transporters. However, the extent of P-gp contribution in the reduced oral bioavailability of candesartan cilexetil is not clear. In this study, a previously developed candesartan cilexetil–loaded self-nanoemulsifying drug delivery system (SNEDDS) was evaluated for its ability to increase the drug oral bioavailability via the inhibition of intestinal P-gp transporters. Despite the developed SNEDDS showing P-gp inhibition activity, P-gp–mediated efflux was found to have a minor role in the reduced oral bioavailability of candesartan cilexetil. On the other hand, the high surfactant concentration used in SNEDDS formulation represents a major challenge toward their widespread application especially for chronically administered drugs. The designed acute and subacute toxicity studies revealed that the degree of intestinal mucosal damage decreases as the treatment period increases. The latter observation was attributed to the reversibility of surfactant-induced mucosal damage. Thus, the developed SNEDDS could be considered as a promising delivery system for enhancing the oral bioavailability of chronically administered drugs.     

The Effect of Digestion and Drug Load on Halofantrine Absorption from Self-nanoemulsifying Drug Delivery System (SNEDDS)

A super-saturated self-nanoemulsifying drug delivery system (super-SNEDDS), containing the poorly water-soluble drug halofantrine (Hf) at 150% of equilibrium solubility (S_eq), was compared in vitro and in vivo with a conventional SNEDDS (75% of S_eq) with respect to bioavailability and digestibility. Further, the effect of digestion on oral absorption of Hf from SNEDDS and super-SNEDDS was assessed by incorporation of the lipase inhibitor tetrahydrolipstatin (orlistat) into the SNEDDS. The SNEDDS contained soybean oil/Maisine 34-I (1:1), Kolliphor RH40, and ethanol at a ratio of 55:35:10, w/w percent. For the dynamic in vitro lipolysis, the precipitation of Hf at 60 min was significantly larger for the super-SNEDDS (66.8 ± 16.4%) than for the SNEDDS (18.5 ± 9.2%). The inhibition of the in vitro digestion by orlistat (1% (w/w)) lowered drug precipitation significantly for both the super-SNEDDS (36.8 ± 1.7%) and the SNEDDS (3.9 ± 0.7%). In the in vivo studies, the super-SNEDDS concept proved valid in a rat model with a significantly larger C_max for the super-SNEDDS (964 ± 167 ng/mL) than for the SNEDDS (506 ± 112 ng/mL). The bioavailability of Hf dosed in super-SNEDDS (32.9 ± 3.6%) and SNEDDS (22.5 ± 6.3%) did not change significantly with co-administration of orlistat (45.5 ± 7.3% and 21.9 ± 6.5%, respectively). However, the pharmacokinetic parameters changed; the t_max of the super-SNEDDS (1.3 ± 0.1 h) and SNEDDS (2.8 ± 1.2 h) were significantly lower when dosed with orlistat (6.0 ± 1.3 and 6.3 ± 1.2 h, respectively). These findings suggest that the role of lipid digestion for the absorption of drugs from SNEDDS may be less important than previously thought.KEY WORDS: absorption, digestion, halofantrine, orlistat, SNEDDS, super-SNEDDS     

依托泊苷固体自微乳的研制及大鼠体内生物利用度研究

目的:制备依托泊苷固体自微乳制剂(SSMEDDS)并研究大鼠灌胃后的药动学行为,提高依托泊苷口服生物利用度.方法:通过相图法得到相应的自乳化区域,并以自乳化速率、粒径及溶解度等作为考察指标筛选处方,寻找出最佳处方配比;采用溶出度实验测定依托泊苷固体自微乳的体外溶出度等理化参数;考察了依托泊苷固体自微乳制剂、市售制剂和原料药混悬液经大鼠灌胃给药后的药动学行为.结果:依托泊苷自微乳的平均粒径为(21.8±1.5)nm,且固体自微乳制剂45 min溶出95％以上,同时药动学数据显示依托泊苷固体自微乳、原料药和市售制剂的AUC分别为12.20、8.25、10.49 mg·h·L-1.结论:VP-16制成固体自微乳制剂后的AUC略高于市售制剂,且大大提高了依托泊苷原料药的生物利用度.     

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.     

口腔粘膜粘附给药系统

本文对口腔粘膜粘附给药系统这一新型给药系统从口腔粘膜的结构与分类、粘膜粘附的理论及影响因素、处方的设计、剂型、质量评价等方面作了介绍。     

Zanamivir Oral Delivery: Enhanced Plasma and Lung Bioavailability in Rats

The objective of this study was to enhance the oral bioavailability (BA) of zanamivir (ZMR) by increasing its intestinal permeability using permeation enhancers (PE). Four different classes of PEs (Labrasol^®, sodium cholate, sodium caprate, hydroxypropyl β-cyclodextrin) were investigated for their ability to enhance the permeation of ZMR across Caco-2 cell monolayers. The flux and P_app of ZMR in the presence of sodium caprate (SC) was significantly higher than other PEs in comparison to control, and was selected for further investigation. All concentrations of SC (10-200 mM) demonstrated enhanced flux of ZMR in comparison to control. The highest flux (13 folds higher than control) was achieved for the formulation with highest SC concentration (200 mM). The relative BA of ZMR formulation containing SC (PO-SC) in plasma at a dose of 10 mg/kg following oral administration in rats was 317.65% in comparison to control formulation (PO-C). Besides, the AUC_{0-24 h} of ZMR in the lungs following oral administration of PO-SC was 125.22 ± 27.25 ng hr ml^-1 with a C_max of 156.00 ± 24.00 ng/ml reached at 0.50±0.00 h. But, there was no ZMR detected in the lungs following administration of control formulation (PO-C). The findings of this study indicated that the oral formulation PO-SC containing ZMR and SC was able to enhance the BA of ZMR in plasma to an appropriate amount that would make ZMR available in lungs at a concentration higher (>10 ng/ml) than the IC₅₀ concentration of influenza virus (0.64-7.9 ng/ml) to exert its therapeutic effect.     

Development and Evaluation of a Novel Mucus Diffusion Test System Approved by Self-Nanoemulsifying Drug Delivery Systems

The aim of this study was the development of a novel mucus diffusion model and the approval thereof by self-nanoemulsifying drug delivery systems (SNEDDSs). For diffusion experiments, various SNEDD formulations were developed, spiked with fluorescein diacetate, and evaluated for their mucus diffusion behavior through an intestinal mucus layer within the novel setup. In brief, SNEDD formulations resulting in particle sizes of 12.0 nm produced 70.3% of diffused model drug through the mucus layer. In comparison, SNEDDSs with particle sizes of 455.5 nm led to a permeation of 8.3% only. Apart from this size dependence, two SNEDDS excipients namely Cremophor RH 40 and triacetin were identified to strongly affect the permeation through mucus. Hence, it could be demonstrated that particle size and single excipients can positively influence mucus diffusion of SNEDDSs. Furthermore, it could be shown that the developed mucus diffusion model is a promising tool for pharmaceutical research in comparison with already established systems as it allows an easy handling coupled with the possibility to test different kinds of mucus in parallel within one setup.     

延迟起效型口服给药系统研究进展

综述了延迟起效型口服给药系统的制备工艺、特点及发展。     

口服自微乳给药系统的研究进展

自微乳给药系统能够显著提高水难溶性药物的口服生物利用度,且最终的给药形式多样,在推进高生物利用度口服递药系统的发展中,表现出良好的应用前景。但自微乳给药系统也存在诸如存储运输不便、稳定性不佳、体外释药评价局限等问题。随着近年来新型载体材料和制剂技术的发展,对固体自微乳给药系统、过饱和自微乳给药系统等新型制剂的研究日益增多,在弥补传统自微乳给药系统不足的同时,可发挥自微乳给药系统的优势。综述自微乳给药系统的辅料组成、促进药物口服吸收的机制、固化方法及体外释药评价方法的研究进展。     

口服渗透泵控释制剂的工艺研究发展

渗透泵控释制剂有很好的发展前景,但目前的研究还很有限。通过查阅文献,本文对口服渗透泵制剂的工艺进行了一些总结,以渗透泵制剂的发展、渗透泵制剂的片芯前处理、渗透泵的包衣与致孔、渗透泵的不同类型制备方法为体系希望加以阐述。     

口服多元释药系统研究进展

本文查阅了相关文献,综述了近年来多元给药系统,如微丸、膜片、微片等,在中西药口服制剂中的研究进展,旨在为新型多元释药系统的研究提供思路和方法.     

喷雾干燥氯诺昔康自微乳化制剂在兔体内的生物利用度

以氯诺昔康片剂为参比制剂,考察了自制喷雾干燥氯诺昔康自微乳化制剂在兔体内的相对生物利用度.以吡罗昔康为内标,采用高效液相色谱法测定兔血浆中的氯诺昔康.6只家兔分别灌胃给予氯诺昔康的片剂或喷雾干燥自微乳化制剂,结果显示,其AUC分别为16 304和26 328 ng·h·ml-1,cmax分别为824和1788 ng/ml,tmax分别为7.0和3.0 h.配对t检验分析表明AUC和cmax具有显著性差异(P＜0.05),tmax具有极显著性差异(P＜0.01),自微乳化制剂的相对生物利用度为161.5％.     

Oral Dispersible System: A New Approach in Drug Delivery System

Dosage form is a mean used for the delivery of drug to a living body. In order to get the desired effect the drug should be delivered to its site of action at such rate and concentration to achieve the maximum therapeutic effect and minimum adverse effect. Since oral route is still widely accepted route but having a common drawback of difficulty in swallowing of tablets and capsules. Therefore a lot of research has been done on novel drug delivery systems. This review is about oral dispersible tablets a novel approach in drug delivery systems that are now a day''s more focused in formulation world, and laid a new path that, helped the patients to build their compliance level with the therapy, also reduced the cost and ease the administration especially in case of pediatrics and geriatrics. Quick absorption, rapid onset of action and reduction in drug loss properties are the basic advantages of this dosage form.     

复合型结肠靶向给药系统的研究进展

口服结肠靶向给药系统(oral colon-specific drug delivery system,OCDDS)具有明显的靶向定位性、可提高局部药物浓度、直接作用于病变部位、降低药物剂量、减少不良反应等优点,常用于提高炎症性肠病和结肠癌的治疗效果。复合型OCDDS较单一型OCDDS具有靶向性好、局部刺激小和药效高等优势,近年来备受研究者们的关注。本文通过对复合型OCDDS在结肠性疾病治疗中的应用进行综述,以期为OCDDS的深入研究和结肠性疾病的临床治疗提供参考。     

口服结肠释药系统的研究进展

目的:综述近年来口服结肠释药系统临床和药学研究动态,为今后在此领域的研究和临床应用提供参考。方法:通过对国内外相关文献资料的整理,对比和分析,总结口服结肠释药系统制剂进展和临床应用的发展方向。结果结论:口服结肠释药系统是通过口服给药,在结肠处定位释放药物的靶向制剂。此类制剂以其靶向释药方式和独特的临床使用价值,越来越广泛地引起了临床医生的关注,同时也成为药学研究领域的一大热点。