桂利嗪自微乳化软胶囊的制备和溶出度的考察

 目的研制桂利嗪自微乳化软胶囊,并考察其溶出度,以降低药物溶出量受pH的影响。方法通过溶解度实验,三相图的绘制,体外乳化和稳定性实验确定最佳处方;以市售硬胶囊为参比制剂测定自微乳化软胶囊(SMESC)的溶出度。结果该自微乳化软胶囊中的乳化剂为聚山梨酯-80,助乳化剂为二甲基异山梨酯,油相为油酸;其最佳比例为4:2:1。SMESC在水,pH6.8缓冲液和0.1mol·L^-1HCl中,45min的溶出度分别为77.9%,87.4%和89.3%,而市售硬胶囊分别为2.4%,3.1%和101.5%。结论桂利嗪自微乳化软胶囊与市售硬胶囊相比,其在水和人工肠液中的溶出度有了显著的提高,且溶出量受pH值的影响较小。     

阿托伐他汀自微乳释药系统的制备和评价

目的制备阿托伐他汀自微乳，为自微乳释药系统的处方设计和体内外评价提供参考。方法采用伪三元相图法研究不同乳化剂、助乳化剂和油相形成微乳的能力和区域，绘制不同处方组成的相图，在此基础上制备阿托伐他汀自微乳，比较温度、介质、稀释等因素对自微乳效率的影响，进行自微乳时间、所成微乳的形态、粒径分布、zeta电位、含量和稳定性等体外评价Beagle犬体内药代动力学研究。结果理想的处方经分散后可得到平均粒径在100 nm以下、呈高斯分布的微乳，稳定性好，自微乳效率高，在Beagle犬体内的吸收明显高于市售片剂。结论本文首次研制阿托伐他汀自微乳，稳定性好，在Beagle犬体内的生物利用度高。     

In vitro and in vivo correlation for lipid-based formulations: Current status and future perspectives

Lipid-based formulations (LBFs) have demonstrated a great potential in enhancing the oral absorption of poorly water-soluble drugs. However, construction of in vitro and in vivo correlations (IVIVCs) for LBFs is quite challenging, owing to a complex in vivo processing of these formulations. In this paper, we start with a brief introduction on the gastrointestinal digestion of lipid/LBFs and its relation to enhanced oral drug absorption; based on the concept of IVIVCs, the current status of in vitro models to establish IVIVCs for LBFs is reviewed, while future perspectives in this field are discussed. In vitro tests, which facilitate the understanding and prediction of the in vivo performance of solid dosage forms, frequently fail to mimic the in vivo processing of LBFs, leading to inconsistent results. In vitro digestion models, which more closely simulate gastrointestinal physiology, are a more promising option. Despite some successes in IVIVC modeling, the accuracy and consistency of these models are yet to be validated, particularly for human data. A reliable IVIVC model can not only reduce the risk, time, and cost of formulation development but can also contribute to the formulation design and optimization, thus promoting the clinical translation of LBFs.     

Pharmacokinetic aspects and in vitro–in vivo correlation potential for lipid-based formulations

Lipid-based formulations have been an attractive choice among novel drug delivery systems for enhancing the solubility and bioavailability of poorly soluble drugs due to their ability to keep the drug in solubilized state in the gastrointestinal tract. These formulations offer multiple advantages such as reduction in food effect and inter-individual variability, ease of preparation, and the possibility of manufacturing using common excipients available in the market. Despite these advantages, very few products are available in the present market, perhaps due to limited knowledge in the in vitro tests (for prediction of in vivo fate) and lack of understanding of the mechanisms behind pharmacokinetic and biopharmaceutical aspects of lipid formulations after oral administration. The current review aims to provide a detailed understanding of the in vivo processing steps involved after oral administration of lipid formulations, their pharmacokinetic aspects and in vitro in vivo correlation (IVIVC) perspectives. Various pharmacokinetic and biopharmaceutical aspects such as formulation dispersion and lipid digestion, bioavailability enhancement mechanisms, impact of excipients on efflux transporters, and lymphatic transport are discussed with examples. In addition, various IVIVC approaches towards predicting in vivo data from in vitro dispersion/precipitation, in vitro lipolysis and ex vivo permeation studies are also discussed in detail with help of case studies.KEY WORDS: Pharmacokinetics, Lipolysis, IVIVC, Efflux transporters, Lymphatic delivery, Food effectAbbreviations: ADME, absorption/distribution/metabolism/elimination; AUC, area under the curve; BCS, biopharmaceutics classification system; BDDCS, biopharmaceutics drug disposition classification system; CACO, human epithelial colorectal adenocarcinoma cells; C_max, maximum plasma concentration; CMC, critical micellar concentration; CYP, cytochrome; DDS, drug delivery systems; FaSSGF, fasted-state simulated gastric fluid; FaSSIF, fasted-state simulated intestinal fluid; FeSSIF, fed-state simulated intestinal fluid; GIT, gastrointestinal tract; IVIVC, in vitro in vivo correlation; LCT, long chain triglyceride; LFCS, lipid formulation classification system; log P, n-octanol/water partition coefficient; MCT, medium chain triglyceride; MDCK, Madin–Darby canine kidney cells; NCE, new chemical entity; P-app, apparent permeability; P-gp, permeability glycoprotein; SCT, short chain triglyceride; SEDDS, self-emulsifying drug delivery system; SIF, simulated intestinal fluid; SMEDDS, self-microemulsifying drug delivery system; SNEDDS, self-nanoemulsifying drug delivery system; Vit E, vitamin E     

Characterization of brusatol self-microemulsifying drug delivery system and its therapeutic effect against dextran sodium sulfate-induced ulcerative colitis in mice

Brusatol (BR) is one of the main bioactive components derived from Brucea javanica, a medicinal herb historically used in the treatment of dysenteric disorders (also known as ulcerative colitis(UC)). Due to its poor aqueous solubility, a novel brusatol self-microemulsifying drug delivery system (BR-SMEDDS) nanoformulation with smaller size, higher negative zeta potential and drug content, and excellent stability was developed. The appearance of BR-SMEDDS remained clear and transparent, and transmission electron microscopy showed microemulsion droplets to be spherical with homogeneous distribution. Pharmacokinetic parameters indicated that oral bioavailability was greatly improved by BR-SMEDDS as compared with aqueous suspension. Meanwhile, the anti-colitis activity of BR-SMEDDS was evaluated on dextran sodium sulfate (DSS)-induced colitis mice model. The result illustrated that the nano-formation significantly reduced the body weight loss, recovered colon length, decreased disease activity index and microscopic score, regulated immune-inflammatory cytokines, diminished oxidative stress and repressed the colonic expression of myeloid differentiation factor 88 (MyD88), toll-like receptor 4 (TLR4) and nuclear factor kappa B p65 (NF-κB p65) proteins. Our findings demonstrated for the first time that BR could effectively attenuate colonic inflammation in mice, at least partially, via favorable regulation of anti-oxidative and anti-inflammatory status and inhibition of the TLR4-linked NF-κB signaling pathway. The BR nano-formulation was superior to BR suspension and sulphasalazine, in treating experimental UC, and exhibited similar effect with azathioprine, with much smaller dosage. The enhanced anti-UC effect of BR might be intimately associated with the improved pharmacokinetic property by SMEDDS. The developed nano-delivery system might thus be a promising candidate for colitis treatment.     

尼索地平自微乳制剂稳定性的影响因素

目的：研究影响尼索地平自微乳制剂稳定性的因素。方法：以温度、稀释倍数、稀释递质种类、絮凝剂及反絮凝剂为主要影响因素，采用测定微乳粒子大小及其分布、Zeta电位进行综合评价。结果：本自微乳制剂对稀释倍数、稀释递质种类、絮凝剂及反絮凝剂敏感，但对温度不敏感，且粒径稳定。结论：本自微乳制剂质量稳定，但稀释后的微乳稳定性下降。     

大蒜素自微乳的制备与质量评价

目的:制备大蒜素(DATS)自微乳制剂,并评价其质量.方法:采用伪三元相图法,以聚氧乙烯氢化蓖麻油RH-40为表面活性剂,无水乙醇为助表面活性剂,油酸为油相,绘制该系统的相图,在此基础上制备DATS自微乳;建立HPLC法测定DATS自微乳中DATS的含量;对自微乳的外观性状、相对密度、黏度、pH值、电导率、形态、粒径及粒度分布、Zeta电位、含量、配伍和稳定性等进行研究.结果:DATS自微乳为无色澄明液体,稳定性良好,相对密度为0.840 g·mL-1,黏度为5.447 mPa·s,遇水形成O/W型微乳,稀释250倍后电镜下观察成圆球形,平均粒径26.4 nm,Zeta电位0.398 mV,pH值5.62,电导率为8.37μs·cm-1,3批制剂的含量分别为31.77,31.45,32.15 mg·mL-1.DATS自微乳与葡萄糖注射液、氯化钠注射液等配伍稳定.结论:DATS自微乳制备工艺简单,性质稳定,质量易控.     

自微乳化系统对细胞紧密连接蛋白的影响

目的从分子细胞水平考察正、负电荷自微乳化系统对细胞紧密连接蛋白复合体的影响。方法建立了模拟小肠上皮细胞结构的Caco-2细胞模型;测定对跨膜电阻和细胞间转运物质甘露醇转运评价制剂对细胞完整性的影响。采用免疫荧光法评价两种自微乳化系统不同稀释倍数对细胞紧密连接蛋白ZO-1和细胞骨架肌动蛋白(actin)的影响。结果负电荷自微乳化系统在不同稀释倍数对跨膜电阻都无显著性影响。正电荷处方在考察的3种稀释倍数显著性降低了跨膜电阻(P<0.05)。细胞单分子层经正电荷自微乳制剂处理2 h，再经过48 h培养，较高稀释倍数跨膜电阻能够完全恢复；50倍稀释的处方不能完全恢复(81.3%)。两种制剂在不同稀释倍数都能显著提高甘露醇的渗透系数(2.9～64.6倍)(P<0.05)，作用与自微乳稀释倍数具有相关性。免疫荧光结果表明，经制剂处理后，影响了actin和ZO-1细胞分布，呈现不连续性。正电荷处方由于静电吸引，可能对细胞膜产生压力，比负电荷处方更能影响actin的分布。对细胞紧密连接影响具有制剂稀释倍数的依赖性。结论自微乳化系统能够提高甘露醇的细胞间转运。通过影响actin和ZO-1的细胞膜分布的作用机制打开细胞紧密连接。     

刺五加总苷自微乳制备工艺的研究

目的研究刺五加总苷自微乳的制备工艺和检测方法。方法考察了刺五加总苷在不同油、乳化剂、助乳化剂中的平衡溶解度,通过伪三元相图的绘制、含药自微乳释药系统自微乳化效率和稳定性考察,确定最佳处方;以刺五加中异嗪皮啶为指标,采用HPLC法测定其在微乳中的量。结果自微乳最佳处方:C af-丙二醇-亚油酸乙酯的比例为16∶4∶5;微乳的平均粒径为40 nm,异嗪皮啶的平均质量浓度为92.6μg/mL。结论刺五加微乳粒径小,稳定性好。以异嗪皮啶为质量控制指标,方法准确可行。     

水飞蓟素自微乳化胶囊的制备及大鼠体内药动学

 目的研制水飞蓟素自微乳化胶囊并对其进行体内外评价。方法通过溶解度试验和伪三元相图的制备筛选处方;制备水飞蓟素自乳化胶囊,考察其乳化后微乳的粒径、形态和体外溶出情况;以原料药作对照,RP-HPLC测定了大鼠灌胃后的血药浓度,用DAS ver1.0软件计算药动学参数。结果以辛癸酸甘油酯为油相,Cremophor RH40为表面活性剂,Transcuto lP为助表面活性剂,制备得自微乳化溶液,稀释100倍后测定粒径为18.8nm,胶囊在10min内基本上能全部溶出;大鼠体内药动学研究结果得自微乳化胶囊和原料药的主要参数分别为t_max=(1.0±0.00),(1.80±0.45)h;ρ_max=(14.62±2.42),(5.75±1.23)mg·L^-1;AUC=(83.60±11.03),(36.00±5.90)mg·h·L^-1。结论将水飞蓟素制成自微乳化胶囊能显著提高其体外溶出和体内吸收。