Development of microparticles and microparticulated tablets containing piperine

Abstract Piper nigrum (black pepper) is used in Indian traditional medicine and its main alkaloid, Piperine (PIP), presents antioxidant, antitumor and neuroprotective pharmacological properties. This substance is insoluble in aqueous media and can irritate the gastrointestinal tract. Aiming to avoid these inconvenient characteristics and enable PIP oral administration, this study suggested the PIP microencapsulation through the emulsion-solvent evaporation method and the preparation of microparticulated tablets by direct compression. An UV-spectroscopy method was validated to quantify PIP. Microparticles and microparticulated tablets were successfully obtained and the microparticles exhibited excellent flow. The scanning electron microscopy images showed that PIP microparticles were intact after compression. The in vitro release showed a controlled release of PIP from microparticles and PIP microparticles from tablets in comparison to PIP and PIP tablets. The release profiles of PIP microparticles and the microparticulated tablets were similar. Therefore, tablets containing PIP microparticles are promising multiparticulated dosage forms because a tablet allows microparticles administration and the intact ones promote a controlled release, decreasing its irritating potential on the mucosa.

Healthier pineapple tart pastry using oleogel-based solid fat replacement

@#Introduction: Pineapple tarts are a commonly consumed Southeast Asian pastry made using solid fats like butter and palm shortening. These solid fats predominantly contain high amounts of saturated fats which have been implicated in negative health effects. However, solid fats impart important textural properties in pastry formation and is not easy to replace. To overcome this challenge, a concept to enhance the nutritional value whilst maintaining the textural properties of pineapple tart pastry formed the basis of this study. Methods: This short study explored the use of “healthy” avocado-olive oil-based oleogels structured with food-grade ethylcellulose (EC), monoglycerides (MG) or its combination (EC-MG) as solid fat replacements to butter and palm shortening. The textural properties of the pastry dough and tart were determined using a texture analyser, while the nutritional content of the pastries was compared. Results: The firmness of pastry dough decreased in the order: EC >> EC-MG > butter ~ MG ~ shortening, while tart hardness decreased: EC > shortening ~ butter > MG > EC-MG. The combination EC-MG oleogel had positive effects on the textural properties by improving the dough workability and reducing the tart hardness compared to EC. Remarkably, the oleogel tart pastries had up to 70% less saturated fat compared to the butter or palm shortening pastries. Conclusion: This study confirms the ability to create healthier pastries whilst maintaining its texture.

Preparation and evaluation of azithromycin-loaded microspheres for oral administration / 中国药科大学学报

@#To mask the bitterness of azithromycin（AZI） and improve patient compliance, an AZI-loaded microsphere (AZI-EC MS) for oral administration was prepared by O/W emulsion solvent evaporation with ethylcellulose (EC) as carrier. The release profiles and taste-masking effect of AZI-EC MS were preliminarily assessed. Its physical properties and morphology were then investigated by differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). The results indicated that the polymer weight of EC could influence the drug release behavior. With a drug polymer ratio of 1∶1 and mixed EC (N22/T10, 7∶3) as carrier, the cumulative release of AZI-EC MS at 0.5 h was less than 40% and reached 90% at 8 h; the drug loading efficiency of microspheres was (48.95 ± 0.86)% with smooth spherical morphology. The AZI bitterness threshold is 9.93 μg/mL with a strong bitter taste, which indicated a better taste masking effect. Therefore, AZI-EC MS prepared in this study can mask AZI bitterness and improve patient compliance, setting the stage for the research of new AZI preparations.

Floating ability and drug release evaluation of gastroretentive microparticles system containing metronidazole obtained by spray drying

Abstract Gastroretentive floating microparticles were developed and evaluated for the controlled metronidazole delivery for treatment of gastric disease. Floating microparticles, varying in proportions of chitosan and hydroxypropyl methylcellulose or ethylcellulose, were obtained by spray drying. Floating microparticles were characterized by physicochemical and in vitro studies, according to their floating ability and drug delivery. Microparticles presented mean diameter from 1.05 to 2.20 µm. The infrared spectroscopy confirmed the drug encapsulation and showed no chemical linkage between microparticles components. X-ray diffraction showed changes in the drug`s solid state, from crystalline to amorphous, indicating partial drug encapsulation, due to the presence of some crystalline peaks of metronidazole in microparticles. All microparticles floated immediately in contact of simulated gastric fluid and both floating and drug release profiles were dependent of microparticles composition. Microparticles samples constituted by chitosan and hydroxypropyl methylcellulose revealed the best relationship between floating duration and drug release, remaining floating during the occurrence of the drug release, ideal condition for the floating gastroretentive systems.

Pharmaceutical films made from the waste material from the preparation of propolis extracts: development and characterization

abstract This study investigated the development and characterized the physicochemical properties of films obtained from by-products (BP) from the preparation of propolis extracts. Films were produced in the presence and absence of a polymeric adjuvant (gelatin or ethylcellulose) and propylene glycol by a solvent casting method. Density, surface topography by scanning electron microscopy, mechanical properties (folding endurance, tensile strength and percentage elongation), water vapour permeability (WVP), moisture uptake capacity, thermogravimetry, differential scanning calorimetry and Fourier transform infrared spectroscopy (FTIR) were determined. The films were a transparent, light greenish-yellow colour, with a uniform surface, and were flexible and easy to handle. The thickness and density of the preparations indicated that the compounds were homogeneously dispersed throughout the film. Mechanical properties were influenced by the film composition; films containing gelatin were more resistant to stress, while those containing ethylcellulose were more flexible. Increasing the adjuvant concentration decreased the elasticity and the rupture resistance, but increased the moisture uptake capacity and WVP of the formulations. BP was thermally stable as were the films. FTIR tests suggested interactions between BP and the adjuvants. This work could contribute to the utilization of BP to prepare films for food and pharmaceutical uses.

resumo Este estudo investigou o desenvolvimento e as características físico-químicas de filmes obtidos com o resíduo (BP), normalmente descartado, advindo da preparação de extratos de própolis. Os filmes foram produzidos com e sem adjuvantes poliméricos (gelatina ou etilcelulose) e propilenoglicol, pelo método de evaporação de solvente. Foram determinadas a densidade, a topografia de superfície usando microscopia eletrônica de varredura, as propriedades mecânicas (resistência à dobra, tensão e elongação), transmissão de vapor de água (WVP), capacidade de absorção de umidade, termogravimetria, calorimetria exploratória diferencial e espectroscopia de infravermelho com transformada de Fourier (FTIR). Os filmes demonstraram coloração verde-amarelada, transparência, uniformidade de superfície, homogeneidade, flexibilidade e fácil manuseio. A espessura e a densidade das preparações indicaram que os compostos estavam dispersos de forma homogênea. As propriedades mecânicas foram influenciadas pela composição dos filmes e aqueles que continham gelatina apresentaram-se mais resistentes enquanto os compostos por etilcelulose demonstraram maior flexibilidade. Com o aumento da concentração polimérica, a resistência e a elasticidade diminuíam, porém aumentou a capacidade de absorção de água e a WVP das formulações. BP apresentou estabilidade térmica assim como os filmes. Os testes de FTIR sugeriram interações entre o BP e os adjuvantes utilizados. Este trabalho pôde contribuir com a utilização de BP na preparação de filmes para uso alimentício e farmacêutico.

Use of hydrophilic and hydrophobic polymers for the development of controlled release tizanidine matrix tablets

The aim of the present study was to develop tizanidine controlled release matrix. Formulations were designed using central composite method with the help of design expert version 7.0 software. Avicel pH 101 in the range of 14-50% was used as a filler, while HPMC K4M and K100M in the range of 25-55%, Ethylcellulose 10 ST and 10FP in the range of 15 - 45% and Kollidon SR in the range of 25-60% were used as controlled release agents in designing different formulations. Various physical parameters including powder flow for blends and weight variation, thickness, hardness, friability, disintegration time and in-vitro release were tested for tablets. Assay of tablets were also performed as specified in USP 35 NF 32. Physical parameters of both powder blend and compressed tablets such as compressibility index, angle of repose, weight variation, thickness, hardness, friability, disintegration time and assay were evaluated and found to be satisfactory for formulations K4M2, K4M3, K4M9, K100M2, K100M3, K100M9, E10FP2, E10FP9, KSR2, KSR3 & KSR9. In vitro dissolution study was conducted in 900 ml of 0.1N HCl, phosphate buffer pH 4.5 and 6.8 medium using USP Apparatus II. In vitro release profiles indicated that formulations prepared with Ethocel 10 standard were unable to control the release of drug while formulations K4M2, K100M9, E10FP2 & KSR2 having polymer content ranging from 40-55% showed a controlled drug release pattern in the above mentioned medium. Zero-order drug release kinetics was observed for formulations K4M2, K100M9, E10FP2 & KSR2. Similarity test (f 2) results for K4M2, E10FP2 & KSR2 were found to be comparable with reference formulation K100M9. Response Surface plots were also prepared for evaluating the effect of independent variable on the responses. Stability study was performed as per ICH guidelines and the calculated shelf life was 24-30 months for formulation K4M2, K100M9 and E10FP2.

O objetivo do presente estudo foi desenvolver matriz de de tizanidina de liberação controlada. As formulações foram projetadas usando o método do componente, central com a ajuda de software Design expert(r), versão 7.0. Utilizou-se Avicel pH 101, no intervalo de 14-50%, como material de preenchimento, enquanto HPMC K4M e K100M, no intervalo de 25-55%, Etilcelulose 10 ST e 10FP, no intervalo de 15-45% e Kollidon SR, na faixa de 25-60% foram utilizados como agentes de liberação controlada, no planejamento de formulações diferentes. Vários parâmetros físicos, incluindo o fluxo de pó para as misturas e variação de peso, espessura, dureza, friabilidade, tempo de desintegração e liberação in vitro, foram testados para comprimidos. Ensaios dos comprimidos foram, também, realizados, tal como especificado em USP 35 NF 32. Avaliaram-se os parâmetros físicos de ambos, mistura em pó e comprimidos, como índice de compressibilidade, ângulo de repouso, variação de peso, espessura, dureza, friabilidade, tempo de desintegração e de ensaio, considerando-os satisfatórios para as formulações K4M2, K4M3, K4M9, K100M2, K100M3, K100M9, E10FP2, E10FP9, KSR2, KSR3 e KSR9. O estudo de dissolução in vitro foi realizado em 900 mL de HCl 0,1 N, tampão de fosfato pH 4,5 e meio 6,8, usando aparelho USP II. Os perfis de liberação in vitro indicaram que as formulações preparadas com Ethocel 10 padrão não foram capazes de controlar a liberação do fármaco, enquanto as formulações K4M2, K100M9, E10FP2e KSR2, com teor de polímero variando entre 40 e 55% apresentaram padrão de liberação controlada de fármaco no meio anteriormente mencionado. Observou-se cinética de liberação de fármaco de ordem zero para as formulações K4M2 , K100M9, E10FP2 e KSR2. Resultados do teste de similaridade (f 2) para K4M2, E10FP2 e KSR2 foram comparáveis com a formulação de referência K100M9. Gráficos de superfície de resposta também avaliaram o efeito da variável independente sobre as respostas. Estudo de estabilidade foi realizado conforme as diretrizes do ICH e a vida de prateleira calculada foi de 24-30 meses para as formulações K4M2, K100M9 e E10FP2.

Hepatic arterial embolization with glycolic acid-ethylcellulose microspheres in treatment of hepatic tumor in rabbits / 第二军医大学学报

Objective To evaluate the therapeutic effects of glycolic acid-ethylcellulose microspheres infused via hepatic artery on hepatocarcinoma in rabbits. Methods Thirty New Zealand white rabbits were implanted with VX2 liver tumor and received CT examination after 13 days. The tumor volumes were calculated; the tumors were numbered according to volume and were divided into 3 groups by random number table. 3 F catheters were inserted via right femoral artery to hepatic artery in all animals; the nutrition arteries of the tumor were observed by injecting contrast media; and then therapeutic agents were given through the catheter. Group A (n=10) was given glycolic acid-ethylcellulose microspheres (0.023 g/1 ml), Group B (n=10) was given lipiodol (1 ml), and Group C (n=10) was given normal saline (1 ml). The liver function and tumor growth were observed before and after treatment; the pathological changes of tumor tissues and the survival of rabbits were observed with 5 randomly selected animals in each group. Results The liver function and the tumor volumes were not significantly different among groups. One week after treatment, AST and ALT levels were significantly higher in Group A and B compared with those in Group C (P<0.05). CT results showed that the tumor growth rates in group A and B were significantly smaller than that in Group C (P<0.01), and that in group A was significantly smaller than that in Group B(P<0.01). Pathological examination showed greatly thickened tumor fibrous capsule and large necrotic area in tumors in Group A and B, with loosely arranged tumor cells, pyknosis and greatly decreased pathologic mitosis. VEGF expression and proliferation activity in Group A were weaker than those in Group B. Compared with Group B and C, animals in Group A had a significantly longer survival time compared with group B and C(P<0.05, P<0.01). Conclusion Transcatheter infusion of glycolic acid-ethylcellulose microspheres is a safe and effective chemoembolization agent for treatment of rabbit hepatic tumors.

Influence of cellulose polymers type on in vitro controlled release tablets containing theophylline

In this study, the effect of ethylcellulose (EC) and 6 types of hydroxypropylmethylcellulose (Methocel® K100M, K100MPRCR, K15MPRCR, K4MPRCR, K4M PR and E4MCR) on release profile of theophylline from matrix tablets was evaluated. Formulations tablets were prepared by either wet granulation or direct compression technique. The tablets were evaluated for physical characteristics and in vitro release of drug was performed as described in USP 30 ed. (Test 3). All formulations with cellulose polymer produced tablets easily and with physicals characteristics in accordance with official limits. Drug dissolution tests showed that formulations with 15 percent of Methocel® K4MPR, 15 percent of Methocel® K4MPRCR and 30 percent of Ethocel® N10STD, obtained by direct compression method, complied with official specifications, in terms of release profile and diffusion was the main mechanism involved in theophylline delivery.

Os efeitos das variáveis das formulações na liberação da teofilina a partir da hidroxipropilmetilcelulose (HPMC) e etilcelulose (EC) em comprimidos matriciais foram estudados. Formulações de comprimidos foram preparadas pelos métodos da granulação úmida ou compressão direta usando diferentes viscosidades de HPMC. Propriedades físico-químicas dos comprimidos e liberação do fármaco foram estudadas conforme dissolução descrita no Teste 3 da Farmacopéia Americana 30ed. Ensaios "in vitro" mostraram que as formulações com 15 por cento de Methocel® K4MPR, 15 por cento de Methocel® K4MPRCR e 30 por cento de Ethocel® N10STD obtidas por compressão direta apresentaram bom perfil de liberação de teofilina e a difusão foi o principal mecanismo envolvido na liberação.

Guar gum/ethylcellulose coated pellets for colon-specific drug delivery / 药学学报

The aim of this work was to investigate guar gum/ethylcellulose mix coated pellets for potential colon-specific drug delivery. The coated pellets, containing 5-fluorouracil as a model drug, were prepared in a fluidized bed coater by spraying the aqueous/ethanol dispersion mixture of guar gum and ethylcellulose. The lag time of drug release and release rate were adjustable by changing the ratio of guar gum to ethylcellulose and coat weight gain. In order to find the optimal coating formulation that was able to achieve drug targeting to the colon, the effect of two independent variables (the ratio of guar gum to ethylcellulose and the coat weight gain) on drug release characteristics was studied using 3×4 factorial design and response surface methodology. Results indicated that drug release rate decreased as the proportion of ethylcellulose in the hybrid coat and the coat weight gain increased. When the ratio of guar gum to ethylcellulose was kept in the range of 0.2 to 0.7, and the coat weight gain in the range of 250% to 500%, the coated pellets can keep intact for about 5 h in upper gastrointestine and achieve colon-specific drug delivery. The pellets prepared under optimal conditions resulted in delayed-release sigmoidal patterns with T5% (time for 5% drug release) of 5.1-7.8 h and T90% (time for 90% drug release) of 9.8-16.3 h. Further more, drug release was accelerated and T90% of the optimum formulation pellets decreased to 9.0-14.5 h in pH 6.5 phosphate buffer with hydrolase. It is concluded that mixed coating of guar gum and ethylcellulose is able to provide protection of the drug load in the upper gastrointestinal tract, while allowing enzymatic breakdown of the hybrid coat to release the drug load in the colon.

Preparation and evaluation of DEET-ethylcellulose microsphere / 第二军医大学学报

Objective:To prepare DEET-ethylcellulose microsphere(DEET-EC) and observe its properties to retard volatilization of DEET. Methods: DEET-EC was prepared with solvent evaporation method. DEET was dissolved in CH 2Cl 2 with EC served as dispersed phase and 1% PVA water solution as continuous phase. The dispersed phase was added into the continuous phase with stirring rate at 1 000 r/min. The stirring rate was changed into 600 r/min after 30 min, and was kept until CH 2Cl 2 was entirely volatilized. After being watered, precipitated and lyophilized for 12 h, DEET-EC was derived, and the shape was observed with electron microscope. The particle size distribution was detected in 500 microspheres with optical microscope. HPLC method was established to determine the embedding ratio and loaded ratio of DEET-EC microsphere. Chromatograph conditions: Diamonsil ODS column (150 mm?4.6 mm), CH 3OH∶H 2O=65∶35 as mobile phase at 1 ml/min, the detected wavelength 210 nm. Results: The DEET-EC was egg-white and had spherical shape. Almost 90% of the MS distributed in 30-70 ?m, while ( ar ) and ( v ) were 49.6 ?m and 51.2 ?m, respectively. The loading ratio was 18.7% and the embedding ratio was 56.1%(n=6). Conclusion: The solvent evaporation method is convenient and simple to prepare DEET-EC microsphere.

Ethylcellulose as sustained release coating membrane of phenylpropanolamine·HCL-resin complexes / 中国药学杂志

To prepare sustained phenylpropanolamine*HCl (PPA*HCl)-resin complexes and to study the factors influencing the in vitro dissolution of it. METHOD: The sustainedPPA*HCl-resin complexes were prepared by coating the complexes with different kinds of ethylcellulose (EC) as coating embranes. The factors influencing the release rate of PPA*HCl from the complexes, such as resin particle size, the viscosity and thickness of coating membrane, the dispersion medium of EC (water or alcohol) as well as thepH and ion strength of dissolution medium were studied in detail. RESULTS: Thefactors above all influenced the dissolution of the complexes to ifferent extent. When prepared by EC 200 Pa*s (150 g*kg-1), the dissolution of the coated complexes in 0.1 mol*L-1 HCl accorded with the requirements of sustained PPA*HCl capsulesof USP ⅩⅩⅢ. ONCLUSION: The sustained PPA*HCl can be prepared by coating the drug-resin complexes with EC.