ABSTRACT
In this study, artemether (ARM)-loaded mixed micelles (MM) composed of the sodium glycocholate (SGC) and soybean lecithin (SL) were prepared by film dispersion method. The effects of hydration medium, SL mass ratio and total concentration of excipients on the solubilization of ARM were investigated and the stability of MM was evaluated. Results showed that the particle size distribution of SGC-SL-MM prepared by phosphate buffer solution (PBS, pH 7.4, 0.05 mol·L-1) was uniform, with an average size of 3.58 ± 0.14 nm and the polydispersity index (PDI) value was 0.16 ± 0.04. The solubility of ARM increased significantly from 0.64 ± 0.04 mg·mL-1 to 13.7 ± 0.13 mg·mL-1 along with the concentration of total excipient increasing from 1.0% to 30.0% (w/w). The calculated results of Arrhenius parameter and storage stability showed that the degradation rate constant of ARM in MM was smaller than that in acetonitrile-PBS (pH 7.4) at either 37 ℃ or 60 ℃. The experimental ARM-MM was clear after storing for two months at 25 ℃ and the degradation of ARM was less than 7.0%. In conclusion, the SGC-SL-MM can not only improve the solubility of ARM in aqueous solution, but also improve its chemical stability in aqueous solution at low temperature.
ABSTRACT
Liposomes are a kind of common drug delivery system in pharmaceutics. They can be used as the dosage form of water insoluble drugs to improve their bioavailability. However, these traditional liposomes have some disadvantages such as low encapsulation efficiency, instability and drug leakage in a long term of storage, which have limited the development of dosage form products based on liposomes. Recently, a novel kind of liposomes, namely composite phospholipids liposomes, has been devel-oped. Compared to traditional liposomes, composite phospholipids liposomes have a very promisingly application prospect due to their advantages including higher encapsulation efficiency and drug-loading efficiency, good stability and no drug leakage. This article re-viewes the research progress in the composite phospholipids liposomes, including their composition, structure, preparation method, function property and recent application in pharmaceutics.
ABSTRACT
Objective: To prepare and optimize the prescription of betulinic acid (BA) ethosomes modified by sodium deoxycholate (SDC) and then to investigate its transdermal penetration as carrier of BA. Methods: The BA ethosomes modified by SDC were prepared by the ethanol injection method. The encapsulation efficiency (EE) was considered as the evaluation index to optimize the prescription of the ethosomes by orthogonal design, and the shape and particle size of the optimized ethosomes were analyzed. The in vitro transdermal absorption of BA was evaluated using Franz diffusion cells. The accumulated permeation amounts and permeation rate of liposomes, ethosomes, and BA ethosomes modified by SDC were compared. Results: The best formulation consisted of soybean lecithin-SDC-BC (18:1:1) and 35% ethanol. The average EE and the particle size were (93.8 ± 1.6)% and (102.3 ± 3.6) nm, respectively. The accumulated permeation amount of BA ethosomes modified by SDC in 12 h was (99.62 ± 9.44) μg/cm2, which was 1.67, 3.85, and 8.33 times of ethosomes, liposomes, and satuated solution containing 10% isopropanol, respectively. Conclusion: The BA ethosomes, modified by SDC with high EE, obviously enhance the percutaneous absorption of BA and might be one of the most perspective percutaneous preparations.
ABSTRACT
Objective: To optimize the two types of colchicine ethosome patches using uniform design and to investigate their in vitro release, transdermal properties, stability, and stimulus. Methods: Two kinds of colchicine ethosomes made of soybean lecithin (SL) and hydrogenated phosphatidy (HP) were prepared using injection method. By the DPS 7.0 sotfware, the uniform design was used to optimize the patch components of colchicines, polyacrylic resin IV, succinic acid, triethyl citrate, and azone in patch pressure-sensitive adhesive, with its initial adhesion and hold tack as indexes. The colchicine ethosomes patches of SL and HP were prepared, respectively. The automated dissolution test analyzer and improved Franz diffusion cell were adopted to compare the in vitro release and transdermal properties of the two types of colchicine ethosomes patches, respectively. Moreover, the preparation stability under different light, humidity, and high temperature conditions was studied, and the skin irritation test for rabbits was carried out. Results: The optimized colchicine ethosome patches by the uniform design adhere with the viscous standards in Chinese Pharmacopeia 2010. The in vitro release of the three types of patches were fitted with the Higuchi equation and their release rates increased in turn, respectively, which were (3.1331 ± 0.3272), (2.8724 ± 0.3481), and (2.3802 ± 0.2134) μg/(cm2·h1/2). Their in vitro transdermal releases were fitted with the zero-class equation and increased in turn, respectively, which were (0.9390 ± 0.0731), (0.8775 ± 0.0908), and (0.6167 ± 0.0816) μg/(cm2·h). During the storage, the HP patches had better stability than the SL patches, especially with the stable color. In the skin irritation test for rabbits, there was no erythema and oedema reactions in 48 h. Conclusion: The HP patches have obviously higer in vitro release rate and transdermal rate, and for its better stability of preparation, the HP patches are superior to the SL ones.
ABSTRACT
No presente trabalho, estudaram-se os efeitos de diversos parâmetros sobre a extração das proteínas caseína e albumina de soro bovino empregando micelas reversas de lecitina de soja. Independentemente da condição empregada, a extração da albumina apresentou baixo rendimento (variando de 0 por cento a 4 por cento, aproximadamente), resultado de um significativo efeito de exclusão por tamanho. Com relação à caseína, o rendimento da extração aumentou 23 vezes com o aumento do tempo de agitação, ou seja, com o maior tempo de contato entre a proteína e o sistema de micelas reversas. A adição de 1-hexanol ao sistema, usado como co-solvente, foi efetiva, aumentando a solubilização da caseína em 36 por cento, sendo os rendimentos da extração desta proteína muito influenciados pelo pH. Os valores máximos de eficiência obtidos foram de 20 por cento em pH 7,9, 80 por cento em pH 5,4 e 100 por cento em pH 5,0 (pH próximo ao pI da proteína).
In this work, the effect of different parameters for extraction of casein and bovine serum albumin (BSA) were studied. Such proteins were extracted by soybean lecithin reversed micelles. BSA extraction was not effective, independent of the extraction conditions employed. Owing to its molar mass, the effect of exclusion by size was clearly observed. The casein extraction yield increased about 23-fold as a function of agitation time. In other words, the increase occurred by using higher contact time between protein and reversed micelles. The use of hexanol as a co-solvent was effective, and increased casein extraction to 36 percent. The extraction values were strongly influenced by pH, and the high extraction yield was obtained under the following conditions: 20 percent at pH 7.9, 80 percent at pH 5.4 e 100 percent at pH 5.0 (close to casein isoelectrical point).