基于生物等效性分析呋塞米片体内外试验的相关性

目的 开展体内外相关性试验以探讨国内生产的呋塞米片的药物溶出度试验是否可以替代生物等效性试验。方法 选择呋塞米片受试与对照制剂,按照中国药典要求和光纤药物溶出度实时测定仪测试方法,监测呋塞米累积溶出百分率并计算f₂相似因子,测定2种制剂的体内血药浓度并计算药动学参数,测算其体内吸收分数、生物利用度和生物等效性,分析呋塞米片体内外试验的相关性。结果 经f₂相似因子方法评估,受试与对照制剂的呋塞米溶出曲线相似,2种制剂的主要药动学参数t_max、C_max、AUC_0-24和AUC_0-∞、生物利用度和生物等效性均差异明显,其体内百分吸收系数和体内外试验的相关性较差。结论 国内生产的呋塞米片的药物溶出度试验尚不能替代生物等效性试验。     

国内外阿那曲唑片溶出曲线相似性评价及采用GastroPlusTM建立体内外相关性模型的研究

目的 建立阿那曲唑片新溶出度检查方法,研究阿那曲唑的溶出行为,评价国内3家片剂产品与原研片溶出曲线的相似性;并建立体内外相关性模型,预测口服阿那曲唑片的药动学参数,评价其生物等效性。方法 新溶出度检查方法：桨法,50 r·min^-1,溶出介质为水900 mL,30 min取样,HPLC测定,限度为标示量的80%。通过GastroPlus^TM软件,结合体外溶出实验结果,建立体内外相关性模型。结果 新建立的溶出度检查方法在0.22~1.10 μg·mL^-1内与峰面积呈良好的线性关系,平均回收率为99.3%（RSD=0.8%,n=9）。国内3家制药公司产品与原研样品在4种溶出介质中的溶出曲线均相似。溶出曲线与软件模拟的体内行为非常相似,吻合度较高。结论 采用浆法,转速为50 r·min^-1,能有效的控制本品的质量。通过体内外相关性的分析,可见建立的体外溶出方法能较好地体现阿那曲唑片在体内的溶出行为。     

国产硝苯地平缓释片的体外溶出度和虚拟生物等效性研究

摘 要 目的：通过体外溶出试验考察4种国产硝苯地平缓释片的质量一致性,并利用GastroPlus软件进行虚拟生物等效性研究。方法: 采用日本橙皮书和中国药典的溶出方法,测定不同厂家硝苯地平缓释片的溶出曲线,利用溶出曲线相似性f2因子法比较溶出曲线相似性。将原研制剂的体外溶出度数据与GastroPlus软件结合计算得到模拟的药物体内吸收曲线,通过与文献实测值比较,选择体内外相关性良好的溶出介质;采用选定的溶出介质进行国产硝苯地平缓释片的溶出试验,得到模拟的体内吸收参数,与原研制剂比较,进行虚拟生物等效性评价。结果: 两种溶出方法的考察结果显示,4种国产制剂与原研制剂的f2因子均小于50;与日本橙皮书方法相比,采用中国药典方法得到的原研制剂溶出曲线的体内外相关性更好。4种国产硝苯地平缓释片的药动学参数Cmax及AUC0~∞模拟值与原研药的实测值相差在±20%以内。结论:4种国产硝苯地平缓释片与原研制剂相比,体外溶出曲线不相似,但体内模拟生物等效。     

基于体外溶出度与体内生物利用度的西罗莫司增溶技术研究

目的 评价不同增溶技术对西罗莫司（sirolimus,SRL）的体外溶出与体内吸收的影响。方法 选取固体分散体（SD）、包合物（IC）、自微乳（SMEDDS）和纳米结构脂质载体（NLC）为SRL的增溶技术。SRL-SMEDDS和SRL-NLC已在前期研究中获得最优处方。另外,以包封率、体外溶出度等为指标,筛选SRL-SD和SRL-IC的处方工艺。分别采用0.4% SDS,水,及pH 1.2、pH 4.5、pH 6.8、pH 7.4缓冲液为溶出介质,考察市售制剂Rapamune^®,以及自制的各增溶制剂的溶出曲线。采用比格犬体内药动学试验,考察上述制剂的体内吸收度。结果 在0.4% 十二烷基硫酸钠（SDS）中,各制剂在2 h的溶出度均超过80%。在pH 1.2的介质中,无法测得SRL-SD的溶出度,而IC、SMEDDS和NLC的溶出度呈先增大后减小的趋势。在其他介质中,SRL的溶出度均有所降低,而SRL-IC显示了最佳的溶出度,未出现明显的降低趋势。体内药动学试验结果显示,原料药、SRL-SD、SRL-IC、SRL-NLC和SRL-SMEDDS的相对生物利用度分别为9.1%、18.7%、33.2%、78.0%、97.6%。结论 SD、SMEDDS、NLC、IC均可提高SRL的体外溶出度和体内吸收度,其中,SMEDDS对SRL的生物利用度改善最为明显。     

难溶性药物口服吸收体内外相关性的研究进展

体内外相关性(in vitro-in vivo correlation,IVIVC)是将药物剂型体外的释药情况与其体内相应的应答关联起来,用数学模型描述药物体外性质(药物溶出的速率或程度)与体内特性(血药浓度或药物吸收量)的关系.它是体外溶出度和体内生物利用度参数的函数.研究某个药物制剂的体内外相关性的目的,在于建立一个可以说明生物利用度的体外质量标准和用作制剂批量生产时的质控指标.水难溶性药物制剂是中国药典规定需要进行生物利用度和溶出度测定的药物类型之一.药物的生物利用度试验操作过程较溶出度试验复杂,在实际工作中,对于具有良好体内外相关性的药物,通过测定体外溶出度来预测难溶性药物的体内生物利用度,进而筛选制剂处方和控制其质量具有重要的意义.一个制剂的改变需要进行一系列生物利用度实验,以证明新制剂与旧制剂具有生物等效性.这过程需要耗费大量的时间和金钱.而具有良好体内外相关性的药物,能很好预测体内释药特征,可以申请豁免生物等效性研究,不仅节约时间,还降低成本.影响药物体内外相关性的因素很多,主要包括体外溶出度研究,体内生物利用度试验研究和拟合模型的数学方法这3个方面.     

口服药物溶出技术与体内外相关性的研究进展

溶出度不仅是口服药物质量评价的重要手段,而且是建立体内外相关性的基础.传统溶出方法由于自身局限,所建立的体内外相关性程度不高.近年来,国内外对口服药物溶出技术进行了大量的研究和改进,以提高其预测体内外相关性的水平.本文对溶出介质、溶出装置以及模型药物与体内外相关性进行了综述.根据模型药物的BCS分类,选择合适的溶出装置和生物相关介质能够获得较好的体内外相关性.     

难溶性药物口服固体制剂的溶出度测定法和体内外相关性的研究进照

综述近年中外文献中有关难溶性药物体外溶出度测定的试验方法、实验条件的选择和影响因素,以及体内外相关性的评价方法.溶出介质的种类、pH值、离子强度、增溶剂和表面活性剂和溶出度仪等均可影响体外溶出度的测定结果.应根据药物的物理化学性质,选择尽可能接近体内状态的方法,可得到更好的体内外相关性.     

难溶性药物口服固体制剂的溶出度测定法和体内外相关性的研究进照

综述近年中外文献中有关难溶性药物体外溶出度测定的试验方法、实验条件的选择和影响因素,以及体内外相关性的评价方法。溶出介质的种类、pH值、离子强度、增溶剂和表面活性剂和溶出度仪等均可影响体外溶出度的测定结果。应根据药物的物理化学性质,选择尽可能接近体内状态的方法,可得到更好的体内外相关性。     

非诺贝特纳米混悬剂溶出度测定与体内吸收的相关性评价

目的 考察非诺贝特纳米混悬剂、原料药粉、微粉化原料药粉的体外溶出特性,研究比较三者在大鼠体内的生物利用度,并对其体内外相关性作出评价。方法 以紫外分光法测定体外溶出度;以高效液相色谱法测定大鼠灌胃给药后的血药浓度;以Wagner-Nelson法计算体内吸收分数,考察体内吸收与体外溶出的相关性。结果 纳米组AUC0-36h 和Cmax分别为原料组、微粉组的10倍和2倍,纳米混悬剂组体内吸收分数fa与体外溶出速率ft的关系为：fa=4.407 9ft- 303.31,r=0.983 8。结论 与原料和微粉组相比,非诺贝特制成纳米混悬剂后,药物的溶出速度和生物利用度均有显著提高,体外溶出与体内吸收相关性良好。     

具明胶交联现象的氟伐他汀钠胶囊溶出度方法研究

目的 针对氟伐他汀钠胶囊交联现象建立溶出度试验方法,为修订现行氟伐他汀钠胶囊溶出度标准提供依据。方法 通过比较氟伐他汀钠胶囊国内外现行标准中溶出度方法,比对国内2家公司样品在4种pH条件下的溶出曲线相似度,考察样品在水和木瓜蛋白酶溶液（酶活力≥ 550 U·mL^-1）这2种溶出介质中的平均溶出度,确定溶出度检查方法：桨法,50 r·min^-1,溶出介质为500 mL水,30 min取样,HPLC测定,限度为标示量的80%;若出现不符合规定情况,以含木瓜蛋白酶溶液（酶活力≥ 550 U·mL^-1）为溶出介质,照上述方法重新试验,应符合规定。结果 本品未发生交联样品批次在水和木瓜蛋白酶溶液中的溶出结果一致,发生交联样品批次在加酶溶出介质中平均溶出量提高5%~7%。结论 该方法重现性好、准确、可靠,能客观反映本品的溶出情况,为统一和修订本品现行标准中溶出度项目提供了依据。     

Forecasting the In Vivo Performance of Four Low Solubility Drugs from Their In Vitro Dissolution Data

Purpose. To assess the usefulness of biorelevant dissolution tests in predicting food and formulation effects on the absorption of four poorly soluble, lipophilic drugs. Methods. Dissolution was studied with USP Apparatus II in water, milk, SIF_sp, FaSSIF, and FeSSIF. The in vitro dissolution data were compared on a rank order basis with existing in vivo data for the tested products under fasted and fed state conditions. Results. All drugs/formulations showed more complete dissolution in bile salt/lecithin containing media and in milk than in water and SIF_sp (USP 23). Comparisons of the in vitro dissolution data in biorelevant media with in vivo data showed that in all cases it was possible to forecast food effects and differences in absorption between products of the same drug with the physiologically relevant media (FaSSIF, FeSSIF and milk). Differences between products (both in vitro or in vivo) were less pronounced than differences due to media composition (in vitro) or dosing conditions (in vivo). Conclusions. Although biorelevant dissolution tests still have issues which will require further refinement, they offer a promisingin vitro tool for forecasting the in vivo performance of poorly soluble drugs.     

In Vivo and In Vitro Diclofenac Sodium Evaluation After Rectal Application of Soft Gelatine Capsules Enabling Application Induced Transformation (AIT) into a Semisolid System of Liquid Crystals (SSLC) for Controlled Release

Purpose. Reverse micellar solutions of diclofenac sodium were encapsulated in soft gelatine capsules. On contact with aqueous media they exhibited an application induced transformation (AIT) into a semisolid system of liquid crystals (SSLC) which slows down drug release. The aim of the present paper was to study in vitro and in vivo drug release from these systems after rectal application. Methods. In vitro drug release was determined in a self-constructed dissolution apparatus to simulate rectal application. For in vivo bioavailability studies rabbits were used as animal models. In vitro release and in vivobioavailability of the capsules was compared to Voltaren^® suppositories. Results. The release profiles of the in vitro experiments show zero-order kinetics. The in vivo bioavailability studies show bioequivalence in terms of AUC for both formulations (capsules and Voltaren^® suppositories). The mean residence time (parameter of sustained release) of the capsules is three time longer in comparison to Voltaren^® suppositories. Conclusions. Rectal administration of capsules provides an appropiate route for controlled release via AIT-SSLC which could be clearly verified in rabbits.     

Formulation,characterization, in vitro and in vivo evaluation of castor oil based self-nano emulsifying levosulpiride delivery systems

Context: Levosulpiride (LSP) is a hydrophobic benzamide derivative used in the treatment of schizophrenia. SNEDDS were extensively practiced for systemic delivery of poorly aqueous soluble drugs to achieve maximum bioavailability.

Objective: The present study was focussed on the formulation, optimisation and evaluation of LSP SNEDDS using castor oil, for enhancement of drug absorption and bioavailability.

Materials and methods: Pseudo-ternary phase diagram was plotted to identify the range of SNEDDS components. Twenty formulations were designed, prepared and characterised by its particle size, zeta potential, viscosity, and stability. In vitro dissolution data modelling was performed. Microscopy, FTIR and in vivo bioavailability studies were conducted for optimum formulation.

Results, discussion and conclusion: F18 containing castor oil, 0.9?mL; PEG 600, 1.36?mL and Tween 80, 2.74?mL was found to be optimum. The optimised formulation had shown uniform globule size, no interactions of LSP with SNEDDS components and higher pharmacokinetic parameters than that of commercial preparation.     

兰索拉唑肠溶片体内外相关性研究

目的考察兰索拉唑肠溶片的体外释放与在beagle犬体内吸收间的相关性。方法利用紫外分光光度法测定肠溶片体外释放度;利用高效液相色谱法测定beagle犬口服给药后的体内血药浓度;以Wagner-Nelson法计算其体内吸收分数,考察体内吸收与体外释放的相关性。结果兰索拉唑肠溶片的体内吸收分数fa与体外释放速率ft的关系为:fa=0.812 2ft–9.874 6,r=0.956 8。结论兰索拉唑肠溶片的体外释放与在犬体内吸收相关性良好。     

Enhanced oral bioavailability of acyclovir by inclusion complex using hydroxypropyl-β-cyclodextrin

Abstract

The therapeutic potential of acyclovir is limited by the low oral bioavailability owing to its limited aqueous solubility and low permeability. The present study was a systematic investigation on the development and evaluation of inclusion complex using hydroxypropyl-β-cyclodextrin for the enhancement of oral bioavailability of acyclovir. The inclusion complex of acyclovir was prepared by kneading method using drug: hydroxypropyl-β-cyclodextrin (1:1 mole). The prepared inclusion complex was characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, NMR spectroscopy and evaluated in vitro by dissolution studies. In vivo bioavailability of acyclovir was compared for inclusion complex and physical mixture in rat model. Phase solubility studies indicate the formation of acyclovir–hydroxypropyl-β-cyclodextrin complex with higher stability constant and linear enhancement in drug solubility with increase in hydroxypropyl-β-cyclodextrin concentration. Characterization of the prepared formulation confirms the formation of acyclovir–hydroxypropyl-β-cyclodextrin inclusion complex. Dissolution profile of inclusion complex demonstrated rapid and complete release of acyclovir in 30?min with greater dissolution efficiency (90.05?±?2.94%). In vivo pharmacokinetic data signify increased rate and extent of acyclovir absorption (relative bioavailability ～160%; p?<?0.0001) from inclusion complex, compared to physical mixture. Given the promising results in the in vivo studies, it can be concluded that the inclusion complex of acyclovir could be an effective and promising approach for successful oral therapy of acyclovir in the treatment of herpes viruses.     

口服缓释制剂体内外相关性评价方法研究进展

《药物评价研究》杂志是由中国药学会和天津药物研究院共同主办的国家级期刊,双月刊,国内外公开发行。办刊宗旨:报道药物评价工作实践,推动药物评价方法研究,开展药物评价标准或技术探讨,促进药物评价与研究水平的提高,为广大药物研究人员提供交流平台。内容与栏目:针对药物及其制剂的评价规范以及药学评价、安全性评价、药效学评价、药物代谢动力学评价、临床评价、     

Design of freeze-dried Soluplus/polyvinyl alcohol-based film for the oral delivery of an insoluble drug for the pediatric use

Abstract

Spironolactone (SL) is a poorly water-soluble drug. Being poorly soluble affects its dissolution rate which in turn affects its oral bioavailability. This work aimed to prepare freeze-dried SL-Soluplus®/polyvinyl alcohol (PVA) oral thin film in an attempt to enhance the drug solubility on one hand and at the same time prepare a solid dosage form convenient for the pediatric use. SL-Soluplus®/PVA films were prepared using polyethylene glycol 400 (PEG 400) as a plasticizer applying the solvent-casting technique. The prepared films were evaluated for their thickness, tensile strength, and in vitro dissolution studies. Box–Behnken design (17 runs) was applied to optimize the effects of the formulation variables on the film properties. The optimized film formulation was freeze-dried after casting so as to enhance the drug dissolution. Moreover, the optimized freeze-dried film was re-characterized in vitro and evaluated in vivo in human volunteers to investigate its palatability and satisfaction. The results showed that the optimized formulation composed of 10% polymer concentration containing Soluplus®:PVA (0.33:0.66) and plasticized with 30% PEG 400 possessed the highest desirability value (0.836). Freeze-drying of the optimized formulation succeeded to improve SL in vitro dissolution due to the preparation of a more porous film compared to the non-freeze-dried one. In vivo evaluation of the optimized freeze-dried film showed high satisfaction among the participating volunteers concerning the ease of administration and sensation thereafter, where all the film specimens dissolved without the need for water and no film residues remained in the mouth following film dissolution. In conclusion, freeze-dried Soluplus®/PVA-based oral thin film proved to be a successful carrier for the oral delivery of insoluble drugs like SL for pediatrics.     

Influence of Tablet Dissolution on Furosemide Bioavailability: A Bioequivalence Study

In order to evaluate the in vitro dissolution and in vivo bioavailability relationship for furosemide, a bioequivalence study was carried out. Furosemide (40 mg) was administered orally to 12 normal volunteers in a 6 × 6 crossover design using six products (five tablets and one solution) obtained from three pharmaceutical companies. Plasma and urine concentrations of furosemide were quantitated by high-performance liquid chromatography (HPLC). Plasma furosemide profiles were analyzed by non-compartmental methods. Compared to the oral solution, all of the formulations exhibited lower peak furosemide concentrations, longer mean residence times, and, in some cases, diminished bioavailability (range, 66–96%). Similar results were obtained when the reference product (a rapidly dissolving tablet) was used as the standard. All of the products failed the 75/75 rule when compared to either reference standard, apparently because of large intersubject variability. The total amount of furosemide excreted in urine could be associated with the percentage drug dissolved (in vitro) at 30 min. The pH 5.6 dissolution medium (compared to pH 4.6) appears to be an appropriate test medium for assuring batch uniformity and bioequivalence of furosemide products.     

Oral Solid Controlled Release Dosage Forms: Role of GI-Mechanical Destructive Forces and Colonic Release in Drug Absorption Under Fasted and Fed Conditions in Humans

Purpose. This study was undertaken to examine the effects of mechanical destructive forces on drug release from controlled release (CR) dosage forms in vitro and in vivo and their colonic release, using two CR tablets of acetaminophen A and B, showing slower and faster erosion rates, respectively. Methods. In vitro release rates were determined by several official methods. Tablets were administered to healthy volunteers under fasting and fed conditions. Results. Both tablets showed similar release rates under mild destructive conditions (e.g., paddle method at 10 rpm) but CR-B showed faster release under highly destructive conditions (e.g., rotating basket method at 150 rpm), where the tablet was eroded. The in vivo release from CR-B was faster than from CR-A, possibly because of enhanced erosion. The variable in vivo release from CR-B indicated large inter-subject differences in destructive GI forces. The fastest in vivo release from CR-B among individuals was approximated by the in vitro dissolution determined by destructive methods such as the rotating basket at 150 rpm. The slowest in vivo release from tablets A and B was lower than the dissolution by the paddle method at 10 rpm. The release from both tablets was markedly reduced at 3–4 hrs after dosing irrespective of feeding conditions which can be attributed to release inhibition in the colon. Conclusions. Effects of GI destructive forces on the tablet erosion and the release inhibition in the colon must be considered in the development of CR dosage forms.     

Prediction of food effects on the absorption of celecoxib based on biorelevant dissolution testing coupled with physiologically based pharmacokinetic modeling

Since the rate-determining step to the intestinal absorption of poorly soluble drugs is the dissolution in the gastrointestinal (GI) tract, postprandial changes in GI physiology, in addition to any specific interactions between drug and food, are expected to affect the pharmacokinetics and bioavailability of such drugs. In this study, in vitro dissolution testing using biorelevant media coupled with in silico physiologically based pharmacokinetic (PBPK) modeling was applied to the prediction of food effects on the absorption of a poorly soluble drug, celecoxib, from 200 mg capsules. A PBPK model was developed based on STELLA^® software using dissolution kinetics, solubility, standard GI parameters and post-absorptive disposition parameters. Solubility, dissolution profiles and initial dissolution rate from celecoxib 200 mg capsules were measured in biorelevant and compendial media. Standard GI parameters (gastric emptying rate and fluid volume) were varied according to the dosing conditions. Disposition parameters were estimated by fitting compartmental models to the oral PK data, since intravenous data are not available for celecoxib. Predictions of food effects and average plasma profiles were evaluated using the AUC and C_max and the difference factor (f₁). An approximately 7-fold difference in the maximum percentage dissolved was observed in in vitro dissolution tests designed to represent the fed and fasted states. By contrast, the food effect estimated by simulating the plasma profiles with the PBPK model predicted only a slight delay in the peak plasma level (1 h), and modest increases in the C_max and AUC of 1.9-fold and 1.3-fold in the fed state, respectively. The PBPK approach, combining in silico simulation coupled with biorelevant dissolution test results, thus corresponds much better to the food effect observed for celecoxib in vivo. Additionally, point estimates of AUC and C_max as well as f₁ calculations demonstrated clear advantages of using results in biorelevant rather than compendial media in the PBPK model.