Application and development of stabilizers in coronary artery bypass grafting / 中国医师杂志

The first robotic heart surgery was performed more than two decades ago. Less invasive cardiac surgical techniques have become increasingly popular in recent years. The integration of emerging materials, computers and engineering technologies has provided the conditions for the application of robotic surgery in various cardiac procedures. Coronary artery bypass grafting (CABG), mitral valvuloplasty/valvuloplasty and radiofrequency/cryoablation for atrial fibrillation are some of the most common surgical procedures. Currently, only a few international cardiac centers have teams specializing in total endoscopic coronary artery bypass grafting. Although some studies have shown good results in robot-assisted heart surgery, questions remain about its safety, cost-benefit ratio, and long-term clinical outcomes. Robotic heart surgery poses higher challenges to myocardial protection and precise anastomosis. The role of stabilizers is to provide a relatively stable field of vision for heart surgery, which is the basis of all non-stop heart surgery. Because of their importance, researchers around the world are constantly exploring how to develop new, more sophisticated stabilizers. This review focuses on the research and development status and development trend of the stabilizer, summarizes the advantages and disadvantages of the current commonly used stabilizer, closely follows the clinic, makes in-depth analysis, and puts forward the key points of the future development of the stabilizer in coronary artery bypass surgery.

Research progress on the preparation and application of flavonoid nanocrystals / 浙江大学学报·医学版

Flavonoids have been reported to possess significant pharmacological activities,such as antioxidant, anti-inflammatory and anticancer effects. However, the low solubility and low bioavailability limits their clinical application. Nanocrystal technology can solve the delivery problems of flavonoids by reducing particle size, increasing the solubility of insoluble drugs and improving their bioavailability. This article summaries nanosuspension preparation methods and the stabilizers for flavonoid nanocrystals, and reviews the drug delivery routes including oral, Injection and transdermal of flavonoid nanocrystals, to provide information for further research on nanocrystal delivery system of flavonoids.

Effect of different diluents on stability of mixed enzyme-labeled antibody / 中国生物制品学杂志

@#Objective To investigate the effect of different diluents on the stability of the mixed enzyme-labeled antibody,and screen a suitable diluent for the mixed enzyme-labeled antibody,which can protect the stability of the cocktail mixture of horseradish peroxidase(HRP) conjugated secondary antibody and alkaline phosphatase(AP) conjugated secondary antibody.Methods Using Tris-HCl buffer as the base solution,four different diluent formulations(A,B,C,D) were prepared with different kinds of stabilizers contained in each formula,such as protein,metalion,surfactant and bacteriostatic agent.Mixed enzyme-labeled antibodies were prepared with different diluents and stored at 2～8 ℃ and 37 ℃,which were detected for the stability by ELISA,enzyme activity assay and immunohistochemistry(IHC) staining.Results D solution [Tris(50 mmol/L)+BSA(1.5%,g/100 mL)+Tween-20(0.3%)+Proclin-950(0.1%,g/100 mL)+sodium chloride(150 mmol/L)+L-Ascorbic Acid(1 mmol/L)+L-methionine(5 mmol/L)+L-histidine(5 mmol/L)+sodium caseinate(1%,g/100 mL)+zinc chloride(0.1 mmol/L)+trehalose(8%,g/100 mL)] was of the optimal protective effect.When stored at 37 ℃ for 10 weeks,the working solution of HRP conjugated secondary antibodies and AP conjugated secondary antibodies showed the highest titer,the activity residual ratios of HRP and AP were 93.46% and96.07%,respectively,and there was no significant difference in IHC results.Conclusion This formula diluent can be used for the preparation of mixed enzyme-labeled antibody working solution.

Study on preparation and formation mechanism of danazol-sodium caseinate composite nanoparticles / 中国药房

OBJECTIVE To prepar e and characterize danazol （DAZ）-sodium caseinate （SC）composite nanoparticles ，and to study the mechanism of preparing nanoparticles in “bottom-up”technology. METHODS SC was used as a stabilizer for regulating nanoparticles，so that DAZ-SC composite nanoparticles were prepared by anti-solvent precipitation method. The particle size ， Zeta-potential，micro-morphology，stability，encapsulation efficiency ，drug loading and in vitro dissolution rate were characterized. Fluorescence spectra ，IR spectra ，FBRM and other methods were used to analyze the interaction mechanism between DAZ and SC. RESULTS The particle size of DAZ-SC composite nanoparticles was （223.7±12.5）nm，and the polydispersity index was 0.274± 0.012. Zeta-potential was －（17.81±1.63）mV（n＝3）. The stability of nano-suspension was good ，the solid properties of DAZ were greatly improved ，and the dissolution rate was significantly increased. SC was statically quenched under the action of DAZ and the secondary structures of SC were changed. The crystallization process of DAZ was controlled under the action of SC ，and the interaction between DAZ and SC was mainly hydrogen bond and van der Waals force. CONCLUSIONS In this study ，DAZ-SC composite nanoparticles are successfully prepared. In the “bottom-up”technology，the interaction between SC and DAZ caused by hydrogen bond and van der Waals force inhibits the growth and agglomeration of drug crystals .

Hands Free 3.c Technique - Step by Step Maximizes the Duration of Sublingual Microcirculatory Image - A Prognosis to Monitor Microcirculation in Patients with Covid-19 and Sepsis

ABSTRACT: The sublingual area is the most used site to assess microcirculation in critically ill patients at bedside. The prerequisite for microcirculation evaluation, using HVM imaging (Handheld Vital Microscopy), is to ensure measurements free of image artifacts, confirming an adequate analysis of blood flow. However, this would only be possible with standardizati on in the process of image capture. Currently, with the Hands On technique, the recommended capture time is 4 to 20 seconds, which is already considered laborious. In this study, the Hands Free 3.C technique proposes an alternative that maximizes the image period of sublingual microcirculation (as suggested by the Second Consensus) for more than 12 minutes, and thus opening the way for future research aiming at therapeutic maneuvers in critically ill patients such as COVID -19 and sepsis.

RESUMEN: El área sublingual es el sitio más utilizado para evaluar la microcirculación junto a la cama en pacientes críticamente enfermos. El requisito previo para la evaluación de la microcirculación, utilizando imágenes HVM (Microscopía Vital Portátil), es asegurar mediciones libres de artefactos de imagen, confirmando un análisis adecuado del flujo sanguíneo. Sin embargo, esto solo sería posible con la estandarización en el proceso de captura de imágenes. Actualmente, con la técnica Hands On, el tiempo de captura recomendado es de 4 a 20 segundos, lo que ya se considera laborioso. En este estudio, la técnica Hands Free 3.C propone una alternativa que maximiza el período de imagen de la microcirculación sublingual (como sugiere el Segundo Consenso) durante más de 12 minutos, y abre así el camino a futuras investigaciones encaminadas a maniobras terapéuticas en pacientes con enfermedades graves como COVID -19 y sepsis.

Hands Free Technique: New Tool Possibility for Image Capture of Sublingual Microcirculation with Handheld Vital Microscopy - HVM

ABSTRACT: New microcirculatory imaging techniques allowed direct observation of microcirculation at the bedside. This study presents a new device that assists the operator with the unprecedented Hands Free technique. To this end, a replica of Handheld Vital Microscopy was developed to simulate the method of capturing the image in the sublingual area, the most used site to assess microcirculation in critically ill patients. We achieved a reduction in the displacement of micros cope replica with a Hands Free method. The immediate consequence is an increase in the stability of HVM replica by 75 times, or more, over the current 4 seconds, during its contact with the sublingual tissue. The device also offers better control of th e pressure of the tip of the HVM replica over the sublingual area. The results demonstrated that the Hands Free technique, operating in the same sublingual area for 900 seconds, should allow for future research aimed at therapeutic maneuvers in patients with serious illnesses.

RESUMEN: Las nuevas técnicas de imagen microcirculatoria permitieron la observación directa de la microcirculación junto a la cama del paciente. Este estudio sin precedentes presenta un nuevo dispositivo que ayuda al operador con la técnica manos libres. Con este fin, se desarrolló una réplica de la Microscopía Vital Portátil para simular el método de captura de la imagen en el área sublingual, el sitio más utilizado para evaluar la microcirculación en pacientes críticos. Logramos una reducción en el desplazamiento de la réplica del microscopio con el método de manos libres. La consecuencia inmediata es un aumento en la estabilidad de la réplica de HVM en 75 veces, o más, durante los 4 segundos actuales, durante su contacto con el tejido sublingual. El dispositivo también ofrece un mejor control de la presión de la punta de la réplica de HVM sobre el área sublingual. Los resultados demostraron que la técnica de manos libres, que opera en la misma área sublingual durante 900 segundos, debería permitir futuras investigaciones destinadas a maniobras terapéuticas en pacientes con enfermedades graves.

Preparation and in vitro evaluation of puerarin nanoemulsion lyophilized powder with glycyrrhizic acid as stabilizer / 中草药

Objective: Puerarin nanoemulsion lyophilized powder (Pue-NE-LP) was prepared using natural surfactant glycyrrhizic acid as stabilizer and evaluated in vitro. Methods: Pue-NE was prepared by high-speed shear and high-pressure homogenization method, and further combined with freeze-drying method to prepare Pue-NE-LP. Taking the average particle size and polydispersity index (PDI) as the evaluation indexes, the optimal prescription and process parameters of this experiment were screened out through a single factor test. The prepared Pue-NE-LP was characterized by physicochemical properties and dissolution in vitro. Results: The average particle size and PDI of Pue-NE-LP prepared with 5% glyceryl caprylate as oil phase, 2.0 mg/mL glycyrrhizic acid as stabilizer, and 7% glucose as lyophilization protectant was (215.1 ± 0.7) nm and (0.133 ± 0.024), respectively. Scanning electron microscopy showed that Pue-NE-LP was irregularly small and uniform in size; X-ray diffraction showed that Pue-NE-LP existed in an amorphous state. In vitro release results showed that the dissolution rate of Pue-NE-LP was significantly higher than the physical mixture. Conclusion: Pue-NE-LP prepared with natural surfactant glycyrrhizic acid as a stabilizer is not only simple to prepare, but also can significantly improve the solubility and bioavailability of puerarin. It provides a reference for the multiple development of Pue-NE formulations.

Chia Seed Mucilage Versus Guar Gum: Effects on Microstructural, Textural, and Antioxidative Properties of Set-Type Yoghurts

Abstract Texture is an important parameter which influences on the quality and acceptability of yoghurts. The utilize of stabilizers in yoghurt manufacturing has become a prevalent application to improve the textural properties of yoghurts. In this context, guar gum obtained from Cyamopsis tetragonolobus is generally used as a natural stabilizer for its thickening and gelling properties. Accordingly, this study evaluated the use of chia seed mucilage as an alternative to guar gum to improve the textural properties of yoghurt. This study focused on the effect of using chia seed mucilage (CSM) and guar gum (GG) at 1, 2, and 3% concentrations on the textural and microstructural characteristics of yoghurts. The results of fortifications with CSM and GG on the physicochemical, sensory, and antioxidative properties of yoghurts were also evaluated. Compared to GG, CSM provided higher antioxidant activity which improved with increasing concentrations of CSM. An enhancement was observed in textural properties of yoghurts containing CSM and GG, but CSM concentrations up to 2% gave better effect on firmness. Besides, the microstructure of yoghurt was enhanced depending on the increase in CSM and GG amounts. No negative effect was determined on the sensory properties of the samples by CSM and GG additions. The results showed that CSM can be used in set-type yoghurt production as an alternative stabilizer by improving firmness and consistency and reducing syneresis. Furthermore, its use is suitable for industrial yoghurt production with regards to sensorial properties.

Implantes endodónticos - Vitalium vs. Titanio Caso clínico con un seguimiento de 18 años / Endodontic implants-Vitallium vs. Titanium Clinical case with 18 years follow-up

Resumen Una de las primeras consideraciones en la Odontología moderna, es preservar y mantener los dientes naturales, por lo que se han buscado técnicas alternativas que permiten conservar los órganos dentales en boca, el mayor tiempo posible. Por esta razón, se presenta un caso clínico donde se logra salvar dos piezas dentales anteriores, que poseían una movilidad grado tres, posterior a un tratamiento ortodóntico que le habían mantenido al paciente por más de dos años. Este caso, se resolvió exitosamente por medio de dos implantes endodónticos: uno de vitalium y otro de titanio, dándole un seguimiento de más de 18 años. A continuación, se expone una técnica de manejo y colocación de estabilizadores endodónticos, tomando en consideración indicaciones y contraindicaciones.

Abstract One of the first and main considerations in modern odontology, is to preserve and maintain natural teeth, reason why alternative techniques have been searched, to preserve dental organs in mouth, as long as possible. That is why this article presents a clinical case where two frontal dental pieces, that had mobility in grade three were saved, after an orthodontic treatment -maintained for more than two years- was removed. The case was successfully solved through two endodontic implants made from vitallium and titanium, with a follow-up for more than 18 years. The following is an exposition of the procedure of endodontic stabilizers, considering indications and contraindications.

Comparative Evaluation of Efficacy and Safety of BepotastineBesilate versus Olopatadine and Ketorolac Combination in Patients with Vernal Keratoconjunctivitis

Objective: Comparative evaluation of efficacy and safety ofBepotastine besilate versus Olopatadine and Ketorolaccombination in patients with vernal keratoconjunctivitis.Materials and Methods: This was a prospective, open label,randomized, comparative clinical study. Hundred patients ofvernal keratoconjunctivitis between 6 to 20 years of age ofeither sex willing to give informed consent were enrolled in thestudy. In Group 1, 50 patients received Bepotastine besilate(0.15%) eye drops twice daily for 8 weeks whereas in Group 2,50 patients received Olopatadine (0.2%) and Ketorolac (0.4%)combination eye drops twice daily for 8 weeks. Symptoms andsigns scoring of VKC were recorded on baseline and at thetime of follow up at 4 and 8 weeks. Safety assessments werealso done in both the drug groups during the study period forany serious adverse effects.Results: After the 2 months of drug therapy, patients in boththe groups showed improvement in the symptoms and signsscoring of VKC. However, there was no statistically significantdifference between the two treatment groups at 4th and 8thweek. Both the drugs were well tolerated without any seriousadverse effect.Conclusion: Both bepotastine besilate versus olopatadine andKetorolac combination ophthalmic solutions were found to beeffective in alleviating the clinical symptoms and signs of VKC.

Preparation of baicalin solid nanocrystal using glycyrrhizic acid as a natural stabilizer / 中草药

Objective To prepare baicalin solid nanocrystal (BCN-SN) stabilized by glycyrrhizic acid (GA) and determine its in vitro release characteristics. Methods The high-speed shearing-high pressure homogenization technology was adopted in the preparation of BCN nanosuspension, and then BCN nanosuspension was solidified into BCN-SN by freeze-drying. The formula and process of BCN-SN were optimized by the single factor experiment with average particle size and polydispersity index (PDI) as indicator. BCN-SN were prepared under the optimal conditions and characterized for crystal-linity and particle size. In vitro release of BCN-SN was also determined. Results The particle size of BCN-SN stabilized by GA and protected by mannitol-GA was (478.0 ± 6.5) nm, and the polydispersity index (PDI) was 0.230 ± 0.015, respectively. The results of SEM showed that BCN-SN was irregular spherical and DSC showed that BCN-SN was amorphous after being prepared into solid nanocrystal. In the in vitro dissolution test, BCN-SN showed a significantly increased dissolution. Conclusion The method employed to prepare the BCN-SN stabilized by GA is simple and low-cost. BCN-SN can significantly improve the dissolution of BCN, which has a broad application.

Effect of lithium carbonate on oxidative stress in patients with bipolar disorder / 上海交通大学学报（医学版）

Objective • To explore the effect on oxidative stress status of lithium treatment in bipolar disorder patients. Methods • This was a case-control study of 61 patients with bipolar disorder (8 manic patients and 53 depressed patients) matched with 49 healthy volunteers from Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine. Patients with bipolar disorder were treated with lithium carbonate for 6 weeks. The 17 Hamilton Depression Rating Scale (HAMD-17), Young Mania Rating Scale (YMRS), Clinical Global Impression-Severity of Illness (CGI-SI) were used to assess the clinical outcomes at baseline and endpoint. The serum levels of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) were measured at baseline and endpoint. The oxidative stress status of the patients and controls was compared, as well as its change after lithium treatment. Results • In the patients with bipolar mania or bipolar depression, the level of SOD was lower (t=5.403, P=0.000) and the levels of GSH-Px and MDA were higher (t=8.371, P=0.000; t=6.063, P=0.000) than those of the normal population, and the level of CAT had no difference in these two groups. There was no difference in the four oxidative stress indicators between the manic state and the depressive state. There were significant differences in plasma GSH-Px and MDA contents after lithium treatment (t=4.352, P=0.000; t=2.720, P=0.009), while there was no significant difference in plasma SOD and CAT levels after lithium treatment. After treatment with lithium, MDA content in bipolar mania and bipolar depression decreased significantly (t=3.072, P=0.018; t=3.532, P=0.001), and that in the manic state decreased more. There was a significant decrease in GSH-Px level in bipolar depression (t=2.880, P=0.006). Conclusion • Oxidative stress injury exists in the patients with bipolar disorder. Lithium carbonate may adjust the imbalance of oxidative stress in these patients, and its effect in different disease states is slightly different.

Preparation, characterization and dissolution characteristics of dragon's blood extract nanosuspensions / 中国中药杂志

The single-factor test was used to optimize the high-pressure homogenization method to prepare the phenolic extract nanosuspensions(DBNs). The physicochemical properties of the obtained nanosuspensions were characterized and the cumulative release in vitro was evaluated. The results showed that the drug concentration was 0.5 g·L~(-1), the mass concentrations of PVPK30 and SDS were 0.5 and 0.25 g·L~(-1), respectively, the probe ultrasonic time was 5 min, the homogenization pressure was 900 bar, and the number of homogenization was 2 times. The prepared DBNs had an average particle size of(168.80±0.36) nm, polydispersity index(PDI) of 0.09±0.04, stability index(SI) of 0.85, and DBNs were stable for storage within 30 days. Scanning electron microscopy showed that the particle size of the dragon's blood extract was reduced and the uniformity was improved in the obtained nanosuspensions. X-ray diffraction pattern and differential scanning calorimetry showed that the phenolic extract of dragon's blood was still in an amorphous state after being prepared into nanosuspensions. The results of saturated solubility measurement showed that the solubility of DBNs lyophilized powder reached 6.25 g·L~(-1), while the solubility of DB raw powder was only 28.67 mg·L~(-1). The in vitro dissolution experiments showed that DBNs lyophilized powder accumulated in gastrointestinal fluid for 8 h. The release amount was 90%,the cumulative release of the raw powder in the gastrointestinal fluid for 24 h was less than 1%, and the solubility and dissolution rate of the DBNs lyophilized powder were significantly higher than the DB raw powder. The method is simple in process and convenient in operation, and can successfully prepare uniform and stable nanosuspensions to improve its solubility, and provides a research basis for solving the application limitation of dragon's blood extract.

Effect of mood stabilizer on gray matter volume in patients with bipolar disorder Ⅰ / 中华行为医学与脑科学杂志

Objective To investigate the abnormal change of gray matter volume in patients with euthymic bipolar disorder Ⅰ (BD-Ⅰ),and to elucidate the relationship between the use of different mood stabilizers and brain structure variations.Methods Voxel-based morphometry (VBM) was used to analyze the volume of local gray matter in 35 patients with BD-Ⅰ and 30 healthy controls(HC).The patients were divided into BD-Ⅰ with lithium group and BD-Ⅰ with valproate group according to different mood stabilizers.The volume differences of gray matter of the three groups were compared by one-way ANOVA.Results Compared with HC,BD-Ⅰ patients showed significantly reduced gray matter volume in the medial frontal cortex (MNI (x,y,z):2,34,-18),orbital frontal cortex (MNI(x,y,z):-32,22,-4),frontal operculum (MNI(x,y,z):38,18,4) and insula cortex (MNI(x,y,z):-32,22,-4) (P＜0.05).There was no significant difference in thevolume of gray matter between BD-Ⅰ with lithium group and BD-Ⅰ with valproate group(P＞0.05).Conclusion Emotional disturbance in patients with BD-Ⅰ may be associated with reduced gray matter volume in the medial frontal cortex,orbital frontal cortex,frontal operculum and insula cortex.There are not significant difference about the effects of lithium carbonate and valproate on cerebral gray matter volume in patients with BD-Ⅰ.

Procedimiento para la producción de una bebida láctea fermentada utilizando lactosuero / Production procedure of a fermented milky drink using lactosuero

The present work was carried out with the objective of designing a fermented dairy beverage using whey as a partial substitute of milk and different commercial stabilizers. An experimental design with three replicates was used for each treatment, where two study factors were manipulated: A. Percentage of serum lactum (10, 20 and 30%) in combination with whole milk and B. Stabilizers types, Obsigel 8AGT, Obsigel 955B and CC-729, all at 0.1% dosing). Their properties were compared with a naturally sweetened yogurt using a 500 mL experimental unit. The treatments were physic-chemical analyzed: syneresis, pH, acidity, °brix and consistency after product packaging. The products also underwent an organoleptic evaluation with 30 untrained judges where the following attributes were rated: texture, aroma, taste, and general quality. The results showed that the best treatment was a3b3 (30% whey + 0.1% CC-729), 4.17pH, 0.67% acidity, 3.13 cm3 consistency and 15.23 ° Brix. Sensorial all treatments were statistically the same with very good acceptance. Due to its greater relevance in physicochemical tests, the stabilizer CC-729 Descalzi (0.1%) showed that it maintains the characteristics of the fermented milk beverage.

El presente trabajo se realizó con el objetivo de diseñar una bebida láctea fermentada utilizando lactosuero como sustituto parcial de leche y diferentes estabilizantes comerciales. Se empleó un diseño experimental con arreglo bifactorial AxB con tres réplicas por cada tratamiento, donde se manipularon dos factores de estudio: A. Porcentajes de lacto suero (10, 20 y 30%) en combinación con leche entera y B. Tipos de estabilizantes (Obsigel 8AGT, Obsigel 955B y CC-729, todos al 0,1% de dosificación). Se compararon sus propiedades con un yogur natural azucarado usando una unidad experimental de 500 mL. A los tratamientos se efectuaron análisis físico-químicos: Sinéresis, pH, acidez, °brix y consistencia después del envasado el producto, además de una evaluación organoléptica con 30 jueces no entrenados donde se calificaron los siguientes atributos: textura, aroma, sabor, calidad general. Los resultados encontrados demostraron que el mejor tratamiento, fue a3b3 (30% de lactosuero + 0,1% CC-729), el cual presentó un pH de 4,17, mientras que la acidez fue un 0,67%, consistencia de 3,13 cm³ y °Brix de 15,23 y sensorialmente todos los tratamientos estadísticamente fueron iguales con muy buena aceptación. El estabilizante CC-729 Descalzi (0,1%) al presentar mayor relevancia en las pruebas físico-químicas mostró que mantiene las características de la bebida láctea fermentada.

Research progress in instability mechanism and stabilizer of anthocyanins in oral liquid preparation of traditional Chinese medicine / 药学学报

Anthocyanins has a high health benefits and biological activity, which can make the solution easily absorbed and has a bright color, beautiful appearance in oral liquid. However, due to its particularity antioxidant activity, it is easy to be affected by the external physical and chemical factors, and then oxidation, polymerization, degradation and other unstable phenomena occurs that seriously affect the stability of products and shelf life. The traditional methods of pH regulation, deoxygenation and light avoidance could not meet the demand of stable anthocyanins. Addition of stabilizer to anthocyanins is a new effective way to improve the stability of anthocyanins. This paper is prepared to summarize systematically the principle and application methods of anthocyanins stabilizers to explore the key technology of clarification and stabilization of traditional Chinese medicine in the natural oral liquid, which may provide theoretical support and technical reference for the development and utilization of anthocyanins stabilizer.

Improvement of preparing technique for compound glycyrrhiza oral solution / 国际药学研究杂志

Objective To obtain a clear and qualified compound glycyrrhiza oral solution by using NaSO3 and EDTA as stabi-lizers and Tween80 as solubilizer so as to solve the problem of morphine content instability. Methods NaSO34g and EDTA 0.6 g as stabilizers,and Tween803 g as solubilizer were added in the traditional method. The pH of the solution was adjusted to 8.0. Then the solution was obtained and filled in the brown polyester bottle. Results The preparation was clear,qualified and the content of mor-phine was steady. Conclusion The improved method is feasible,simple,stabilized and suitable for manufacturing.

Study on feasibility of puerarin nanocrystalline self-stabilizied Pickering emulsion / 中草药

Objective: To investigate the feasibility of Pickering emulsion stabilized by puerarin nanocrystalline. Methods: The new puerarin nanocrystalline self-stabilized Pickering emulsion (Pu-NSSPE) has been developed using the high pressure homogenization method. The influences of drug addition sequence, property, and construction of oil phase, drug concentration, oil/water ratio, homogenization pressure, and pH value of water phase on the formation and stability of Pu-NSSPE were investigated to optimize the preparation technology of Pu-NSSPE. Results: The stability and structure of optimized Pu-NSSPE were studied. It was difficult to form stable Pu-NSSPE if puerarin was first added into water during preparation. The three-phase contact angle and pH value of water phase were key factors for the formation and stability of Pu-NSSPE. Pickering emulsion could be stabilized by puerarin nanocrystalline only when three-phase contact angle of puerarin approaches 90° and water phase was alkaline. When the drug concentration was between 1.0-5.0 mg/mL, stable Pu-NSSPE could be formed. The higher oil/water ratio was, the more oil creamed from Pu-NSSPE was. Low homogenization pressure (below 80 MPa) could not form stable Pu-NSSPE. The size of emulsion droplet of optimized Pu-NSSPE was (10.66 ± 4.81) μm, and drug content was 4.28 mg/mL. The appearance, morphology, and size of emulsion droplets, Zeta potential and drug content were not changed significantly after storage for six months at room temperature. The adsorption of puerarin at the surface of oil droplets was observed by fluorescence microscope. Conclusion: Nanocrystalline of puerarin could stabilize Pickering emulsions, which will provide a promising drug delivery system for puerarin.

Preparation of poorly soluble drug curcumin nanocrystalline self-stabilized Pickering emulsion / 中草药

Objective: To prepare curcumin nanocrystalline (Cur-NC) self-stabilized Pickering emulsion (Cur-NCSPE). Methods: Cur-NCSPE was prepared by high pressure homogenization. The influences of homogenization pressure on Cur-NC size and drug content on Cur-NCSPE formation were studied. The morphology and structure of emulsion droplets were observed by optical microscope and scanning electron microscope. Furthermore, the stability and in vitro release properties of Cur-NCSPE were evaluated. Results: The particle size of Cur-NC was slightly changed when homogeneous pressure was greater than 100 MPa. With the increase of Cur, the amount of Cur-NC on the surface of oil droplets increases, and the particle size decreases. When the amount of drug added can completely cover the surface of oil droplets, increasing the amount of drug had little effect on the particle size. Cur-NCSPE was more stable than Cur-NC and Cur, and the in vitro release rate of Cur-NCSPE was significantly higher than that of Cur-NC and Cur coarse power. Conclusion: The Cur-NCSPE is prepared successfully, which is expected to provide a novel oral administration technology platform for the poorly soluble drugs.

Pullulan as a stabilizer agent of polymeric nanocapsules for drug delivery

ABSTRACT Polymeric stabilizers have received attention in the preparation of nanostructured systems due to their ability to enhance formulation stability. Considering this, the objective of this work was to prepare poly(ε-caprolactone) nanocapsules using the pullulan as a polymeric stabilizer. The nanocapsules were prepared using the interfacial deposition method of preformed polymers and they were characterized in terms of pH, average diameter, polydispersity index, zeta potential, beclomethasone dipropionate content, encapsulation efficiency, photostability and drug release profiles. The formulations showed physicochemical characteristics consistent with nanocarriers for drug delivery such as: average diameter lower than 270 nm, polydispersity indexes lower than 0.2, negative zeta potential (-22.7 to -26.3 mV) and encapsulation efficiencies close to 100%. In addition, the nanocapsules were able to delay the beclomethasone dipropionate photodegradation under UVC radiation and by the dialysis bag diffusion technique, the nanocapsules were able to prolong the drug release. Thus, pullulan could be considered an interesting excipient to formulate polymeric nanocapsules.