Diseño y caracterización de un sistema de entrega de fármacos autoemulsificable (SEDDS) de estradiol por diagramas de fases pseudoternarios y pruebas fisicoquímicas

Introducción: el estradiol es una hormona esteroide sexual femenina usada ampliamente como terapia hormonal que presenta una baja biodisponibilidad, debido a su baja solubilidad acuosa y a su alta hidrofobicidad, perteneciendo a la clase II del sistema de clasificación de biofarmacéutica. Objetivos: diseñar y caracterizar un sistema de entrega de fármacos autoemulsificable (SEDDS) para el fármaco estradiol por pruebas fisicoquímicas con el fin de obtener la relación óptima que permitiera mejorar su solubilidad acuosa, velocidad de disolución y potencialmente su biodisponibilidad. Método: estudios de solubilidad en diferentes solventes, diagramas de fases pseudoternarios constituidos por aceites, tensioactivos, cotensioactivos y agua permitieron reconocer las diferentes regiones de formación de SEDDS e identificar los porcentajes de excipientes que conducen a la formación de soluciones isotrópicas; las formulaciones resultantes fueron caracterizadas en tiempo de autoemulsificación, robustez a la dilución, punto de nube y perfil de disolución en capsula dura. Resultados: las formulaciones que contenían Capmul MCM®, Kolliphor® RH40 y Transcutol®, tuvieron un tiempo de autoemulsificación de aproximadamente 1 min; fueron estables en tres distintos pH (1,2; 4,5 y 7,2), en diferentes volúmenes de dilución, exhibiendo una apariencia transparente, ligeramente azulada, sin precipitados, o separación de fases, puntos de nube mayores en comparación de las formulaciones que contenían Gelucire® 44/14. Conclusiones: las estrategias de caracterización empleadas en el desarrollo de esta investigación demostraron ser eficientes para la selección adecuada de excipientes y su proporción óptima para el diseño eficaz de un sistema de entrega de fármaco autoemulsificable (SEDDS).

SUMMARY Introduction: Estradiol is a female sex steroid hormone widely used as hormonal therapy that has low bioavailability, due to its low aqueous solubility and high hydro-phobicity, belonging to class II of the Biopharmaceutical Classification System. Aim: To design and characterize a self-emulsifying drug delivery system (SEDDS) for the drug estradiol by physicochemical tests to obtain the most optimal ratio that would improve its aqueous solubility, dissolution rate, and potentially its bioavailability. Method: Solubility studies in different solvents; pseudo ternary phase diagrams made up of oils, surfactants, co-surfactants, and water, allowed to recognize the different regions of SEDDS formation and identify the percentages of excipients that lead to the formation of isotropic solutions; The resulting formulations were characterized in autoemulsification time, robustness to dilution, cloud point and dissolution profile in a hard capsule. Results: The formulations containing Capmul MCM®, Kolliphor® RH40, and Transcutol®, had an autoemulsification time of approximately 1 minute; were stable at three different pHs (1.2, 4.5 and 7.2), at different dilution volumes, exhibiting a transparent, slightly bluish appearance, without precipitates, or phase separation, higher cloud points compared to the formulations containing Gelucire® 44/14. Conclusions: The characterization strategies used in the development of this research proved to be efficient for the adequate selection of excipients and their optimal ratio for the effective design of a self-emulsifying drug delivery system (SEDDS).

Introdução: o estradiol é um hormônio esteroide sexual feminino amplamente utilizado como terapia hormonal que apresenta baixa biodisponibilidade devido à sua baixa solubilidade aquosa e alta hidrofobicidade, pertencente à classe II do sistema de classificação biofarmacêutica. Objetivos: projetar e caracterizar um sistema de liberação de drogas autoemulsificante (SEDDS) para o fármaco estradiol por meio de testes físico-químicos a fim de obter a proporção ideal que melhore sua solubilidade aquosa, taxa de dissolução e potencialmente sua biodisponibilidade. Método: estudos de solubilidade em diferentes solventes, diagramas de fases pseudoternários compostos por óleos, tensoativos, cotensoativos e água permitiram reconhecer as diferentes regiões de formação de SEDDS e identificar as porcentagens de excipientes que levam à formação de soluções isotrópicas; as formulações resultantes foram caracterizadas quanto ao tempo de autoemulsificação, robustez à diluição, ponto de turvação e perfil de dissolução da cápsula dura. Resultados: as formulações contendo Capmul MCM®, Kolliphor® RH40 e Transcutol®, tiveram um tempo de autoemulsificação de aproximadamente 1 min; foram estáveis em três diferentes pH's (1,2; 4,5 e 7,2), em diferentes volumes de diluição, apresentando aspecto transparente, levemente azulado, sem precipitados ou separação de fases, pontos de turvação mais elevados em relação às formulações contendo Gelucire® 44/14. Conclusões: as estratégias de caracterização utilizadas no desenvolvimento desta pesquisa mostraram-se eficientes para a seleção adequada de excipientes e sua proporção ideal para o desenho eficaz de um sistema de liberação de fármacos autoemulsificante (SEDDS).

Preparation of resveratrol nanoemulsions and evaluation their pharmacokinetics profiles in rats in vivo / 中草药

Objective :To fabricate resveratrol nanoemulsions and probe their pharmacokinetics profiles in rats in vivo. Methods The nanoemulsions of resveratrol were tailored by using aethylis oleas as the oil phase, Cremophor RH40 as emulsifiers, absolute alcohol as co-emulsifiers, respectively. The formulation was optimized by pseudo-ternary phase diagrams and their physicochemical properties of nanoemulsions were characterized by particle size distribution, transmission electron microscope (TEM), and Fourier transform infrared spectroscopy (FTIR). The pharmacokinetics experiments were also performed in rats after gavage and the plasm concentration of resveratrol were determined by HPLC as well as the profiles of pharmacokinetic parameters were obtained by Drug and Statistics (DAS) software. Results: The formula of nanoemulsions were as follows: the ratio of resveratrol-aethylis oleas-mixture surfactant- distilled water was 1:10:24:65. The average particle size diameters of prepared resveratrol nanoemulsions were about 40 nm and the droplets of nanoemulsions were in spherical shape observed by TEM. The results of IR disclosed that the active trans-resveratrol presented in the oil droplet of the nanoemulsions. Compared with resveratrol suspensions, the bioavailability of resveratrol nanoemulsions was increased 1.45-fold, and Cmax reached to 1.93-fold. Conclusion : These results indicated that nanoemulsions may be a promising tool for the delivery of resveratrol.

Study on Preparation of Triptolide-glycyrrhetic Acid Compound Microemulsion and Its Physicochemical Properties and in vitro Release Characteristics / 中国药房

OBJECTIVE： To establish content determination method of Triptolide-glycyrrhetic acid compound microemulsion， optimize the formula and investigate its physicochemical properties and release rate in vitro. METHODS： The content of Triptolide- glycyrrhetic acid compound microemulsion was determined by UPLC. The determination was performed on ACQUITY UPLC BEH C18 column with mobile phase consisted of 0.1％ formic acid aqueous solution-acetonitrile （gradient elution） at the flow rate of 0.4 mL/min. The column temperature was 40 ℃. The detection wavelength was set at 218 nm， and sample size was 5 μL. Pseudo-ternary phase diagrams were drawn by water titration method. Using oil phase， surfactants and co-surfactants as index， the formula was optimized， and in intro release characteristics was investigated by in vitro release test. RESULTS： The linear range of triptolide and glycyrrhetinic acid were 1-40 μg/mL（r＝0.999 7） and 10-400 μg/mL（r＝0.999 8）， respectively. The limits of quantitation were 0.5 and 0.8 μg/mL； the limits of detection were 0.1 and 0.2 μg/mL. RSDs of precision， stability and reproducibility tests were all less than 2％. Average recoveries were 100.32％-101.15％ （RSD＝0.36％， n＝6）， 99.78％-101.42％ （RSD＝0.59％，n＝6）. The optimal formula included that medium chain triglyceride as oil phase， polyethylene glycol hydroxy stearate as surfactants， ethanol as co-surfactants， water as water phase， the proportion of them was 8 ∶  28 ∶ 14 ∶ 50. The obtained microemulsion was O/W type， being transparent and clear， with average diameter， average polydispersity index and average viscosity of （62.38±3.44） nm， 0.096±0.001 and （26.84±1.10） mPa·S. Within 24 h， cumulative release rates of triptolide and glycyrrhetinic acid in obtained microemulsion were 99.8％ and 99.7％ （in PBS pH 2.0）， 99.3％ and 99.4％ （in PBS pH 7.4）， 98.9％ and 98.4％ （in PBS pH 9.0）， respectively. Triptolide and glycyrrhetinic acid released faster in the single microemulsion than in the compound microemulsion. CONCLUSIONS： Established content determination method is simple and stable. The optimized formula is stable and feasible. Obtained iriptolide-glycyrrhetinic acid compound microemulsion show better sustained-release effect than sigle microemulsion.

Development of self-nanoemulsifying tablet (SNET) for bioavailability enhancement of sertraline

The purpose of the study was to combine the advantages of self-nanoemulsifying drug delivery systems and tablets as a conventional dosage form. Self-nanoemulsifying drug delivery system (SNEDDS) was prepared to enhance the solubility and thus oral bioavailability of sertraline. Aqueous titration method was used to prepare the liquid SNEDDS; ternary phase diagrams were constructed and based on smaller droplet size (24.8 nm), minimum viscosity (153.63 cP) and polydispersity index (0.182), higher percentage transmittance (95%) and in vitro drug release (97%), an optimum system was designated. Liquid SNEDDS was transformed into free-flowing powder by solid adsorption technique followed by compression into tablets. In vitro release of sertraline from liquid and solid SNEDDS was found to be highly significant compared to plain sertraline (p<0.01). Pharmacokinetic studies after oral administration of liquid and solid SNEDDS in rats showed about 6-and 5-fold increased absorption of sertraline compared to the aqueous suspension of sertraline. These studies demonstrate that the solid SNEDDS are promising strategies for successful delivery of poorly water-soluble drug like sertraline

Effect of oleic acid and isosorbide mononitrate loading on the phase diagrams and in vitro release profiles of glyceryl monooleate liquid crystalline system / 中国药科大学学报

@#The aim of the study was to investigate the effect of oleic acid(OA)and isosorbide mononitrate(ISMN)on the phase diagrams of glyceryl monooleate(GMO)liquid crystalline systems and release of ISMN from them. Liquid crystalline systems of GMO/H2O, GMO/H2O/ISMN and GMO/H2O/OA were prepared and their phase diagrams were plotted. Investigation of water absorption of GMO and ISMN release profiles shown that the release mechanism of ISMN was diffusion-controlled. Increased drug loading accelerated the release rate. However, the increased loading of OA decreased ISMN release. The result could offer practical basis for drug loading and the selection of additives in GMO liquid crystalline system.

Effect of solvents on the formation thermodynamics of baicalein-nicotinamide cocrystals / 中国药科大学学报

@#The purpose of this study was to investigate the formation thermodynamics of baicalein(BE)-nicotinamide(NCT)cocrystals in three solvents including ethyl acetate, acetone and trichloromethane. The solubilities of BE, NCT and BE-NCT in the above solvents at 25 °C were measured. Ternary phase diagrams(TPDs)of the BE-NCT-solvent systems were established. The non-linear fitting equation according to 1 ∶1 complexation mechanism of BE-NCT cocrystals demonstrated a good correlation between calculated and experiment data. ΔG0< 0 suggested that BE-NCT cocrystal formation was a spontaneous process. Among the organic solvents studied, the absolute value of ΔG0 in trichloromethane was significantly lower than that in the other two solvents. In addition, the cocrystallization zone in trichloromethane was far away from stoichiometric line. This study provides a theoretical foundation for solvent selection and preparation-condition optimization of BE-NCT cocrystals.

Optimization and Preliminary Evaluation the Formulation of Self-microemulsifying Drug Delivery System of Potassium Dehydroandrographolidi Succinas / 世界科学技术-中医药现代化

The self-microemulsion formulation of potassium dehydroandrographolidi succinas (PDS) has been optimized and the performance in vitro has been evaluated preliminary. Kinds of prescription accessories were screened by solubility based on the emulsifying result and efficiency, particle size of emulsions. The optimal formulation composition and compatibility proportion were determined by orthogonal design and pseudo-ternary phase diagrams. The appearance, particle size, Zeta potential and stability of this formulation were also investigated. The optimized prescription of PDS was 10% MCT, 40% Tween-20 and 50% glycerol. It can spontaneously form a transparent pale blue opalescent emulsion with emulsification time 31.27 s, particle size 37.1 nm, Zata potential -17.4 mV and good stability.

Effect of polymers on the formation thermodynamics of adefovir dipifoxil-saccharin cocrystal / 中国药科大学学报

@#The aim of this study was to investigate the effect of polymers on the formation thermodynamics of adefovir dipifoxil(AD)-saccharin(SAC)cocrystal. In the absence and presence of polymers such as polyethylene glycol, ethyl cellulose, polyvinylpyrrolidone and Eudragit E100, solubilities of AD and SAC in ethanol solution containing different concentrations of SAC at variable temperatures were determined by high-performance liquid chromatography(HPLC). Appropriate mathematical model for the description of the influence of polymers and temperature on the solubility of AD-SAC cocrystal was established. The ternary phase diagrams were set up using the assayed solubilities data, and they were used to predict changes of cocrystals solubility and product yield. Addition of polymers resulted in increased solubility of AD-SAC cocrystal, decreased complexation constants(K11), enhanced solubility products(Ksp), but there was a gradually decreased free energy change(ΔG0). The areas of homogeneous liquid phase and pure solid cocrystal in equilibrium with the liquid phase in ternary phase diagrams were also found to be larger. Therefore, although there was no change to the spontaneity of AD-SAC cocrystal formation, there existed retardation to cocrystal formation and reduction in product yield of pure cocrystal in the presence of polymers. Moreover, application of polymers could broaden the concentration range of AD and SAC solutions when solution crystallization was selected to prepare cocrystal.

Relationship between composition and organizational levels of nanostructured systems formed by Oleth 10 and PPG-5-Ceteth-20 for potential drug delivery

In this paper, nanostructured systems were developed, with the aid of ternary phase diagrams, from two surfactants, of differing degrees of lipophilicity (PPG-5-Ceteth-20 and the Oleth 10) and two oil phases (oleic acid and isopropyl myristate). It was observed that there were differences between the four resulting phase diagrams in the physical properties of the systems they represent. Thus, due to the capacity of Oleth 10 (as surfactant) and oleic acid (as the oil phase) to reduce interfacial tension, large regions of translucent systems were seen on the diagrams produced by them. By polarized light microscopy, it was possible to identify the isotropic and anisotropic properties of these systems, which were confirmed by small-angle X-ray scattering (SAXS) analysis. Furthermore, it was found that increasing the proportion of water in the formulations led to more highly organized structures, resulting in narrower and well defined SAXS peaks.

Neste trabalho, os sistemas nanoestruturados com diferentes níveis de organização foram obtidos através dos diagramas de fase ternários, utilizando tensoativos com de diferentes graus de lipofilicidade, o PPG-5-Ceteth-20 e o Oleth 10, e ácido oleico e miristato de isopropila como fases oleosas. Através dos diagramas foi possível observar diferenças significativas relacionadas com as características dos sistemas, devido à capacidade que o Oleth 10 (como tensoativo) e o ácido oleico (como fase oleosa) têm em diminuir a tensão interfacial, facilitando a formação de uma extensa região de sistemas transparentes. Através da microscopia de luz polarizada foi possível identificar as características isotrópicas e anisotrópicas dos sistemas, sendo posteriormente confirmadas pelas curvas de dispersão de raios X de pequeno ângulo (SAXS). Além disso, foi possível verificar que o aumento de água nas formulações proporcionou maior estruturação, permitindo a observação de picos mais estreitos e definidos nas curvas de SAXS.

Preparation of coenzyme Q10 submicron emulsion for intravenous injection and study on its pharmacokinetics in rats / 中国药学杂志

OBJECTIVE: To investigate the O/W submicron emulsion injection formulation, and investigate its pharmacokinetics in the rat. METHODS: Pseudo-ternary phase diagrams were established using the water titration method. The effects of different surfactants, cosurfactants and Km values on the phase diagram were investigated, and the prescription of submicron emulsion formulation was optimized. Stability of coenzyme Q10 submicron emulsion was evaluated, and the pharmacokinetics in the rat after intravenous injection was study. RESULTS: Coenzyme Q10 submicron emulsion consisting of Poloxamer188/Lipoid S100/ethanol/PEG400/water has the lower viscosity, the smaller size and the higher encapsulation efficiency. An obvious sustained-release effect of coenzyme Q10 submicron emulsion was observed after iv injection in the pharmacokinetics experiment, and mean residence time is 6. 55 h. CONCLUSION: The optimized coenzyme Q10 submicron emulsion consumes smaller quantities of auxiliary materials and shows good stability. Moreover, it is easy to manufacture and convenient for clinical use. Copyright 2012 by the Chinese Pharmaceutical Association.

Preparation and evaluation of self-microemulsifying drug delivery systems containing tanshinone Ⅱ_A / 中草药

Objective To optimize the formulation of self-microemulsifying drug delivery systems containing tanshinone ⅡA(tanshinone ⅡA-SMEDDS) and assess the quality of tanshinone ⅡA-SMEDDS. Methods Pseudoternary phase diagrams were used to choose the oil,emulsifier,co-emulsifier,and their proportion in the formulation on the basis of the ability to form emulsions and regions. Then the self-emulsifying time,droplet and morphology,size distribution,?-potential,stability,and other aspects of the quality were evaluated. Results The formulation of tanshinone ⅡA-SMEDDS was as follows:ethyl oleate-Labrasol-PEG 400=10%:45%:45%,drug loading ratio was 2.25 mg/g. The self-microemulsifying time of tanshinone ⅡA-SMEDDS in 0.1 mol/L hydrochloric acid solution was less than 1 min,the emulsion drops were spherical shape with average particle size of (84.9?2.1) nm and the average ?-potential (-24.0?1.15) mV (n=3). So tanshinone ⅡA-SMEDDS was stable. Conclusion In this paper,the tanshinone ⅡA-SMEDDS has a good self-emulsifying performance. It is expected to further stabilize the preparation of tanshinone ⅡA self-microemulsifying agents.

Research and preparation for nanoemulsion of Fructus Perillae oil / 中草药

Objective To study the preparation of Fructus perrillae oil nanoemulsion and its quality evaluation. Methods The formulations of Fructus Perrillae oil nanoemulsion were optimized by drawing the pseudoternary phase diagrams and investigating the form, viscosity, particle size distribution, stability, conductance, and refractiratio. Results The optimal formulation was composed of wheat oil and cremophor RH40, electron microscopy presented Fructus Perrillae oil nanoemulsion as small spherical drops, viscosity was (5.49?0.02)/mm2?s-1, conductance was 316/ms-1, refractiratio was (1.124?0.002 50), and mean diameter of particle was (50.3?1.1) nm.The average recovery determined by GC was 98.9%, its mean RSD was 0.88%. Conclusion The solubility and stability of Fructus Perrillae oil are promoted by nanoemulsion with better produncibility. It is a favorable medical matrix.