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약물 전달체에 prednisolone을 분산시켜 제조한 고분자 매트릭스를 pH 1.2 및 pH 7.4 완충용액에서 약물 방출실험을 하였다. 약물 방출시간은 pH 1.2보다 pH 7.4에서 더 지연되었으며 약물 전달체의 함유량이 증가함에 따라 약물 방출시간도 지연되었다. 이러한 거동은 약물 전달체가 산성에서 팽윤을 더 잘하기 때문이다. 약물 전달체의 종류에 따라 지연된 약물 방출시간은 키토산 고분자 매트릭스의 경우가 가장 길었으며, 술폰화키토산 고분자 매트릭스, 키토산·염고분자 매트릭스의 순서였다. 특히 이러한 제형들은 초기 방출속도를 억제하는 팽윤성 방출조절형 제제임을 화인할 수 있었다. The release experiments of drug were operated in the buffer solutions of pH 7.4 and pH 1.2 by using drug carriers with prednisolone for delivery drug. The release time of drug was more delayed in pH 7.4 than in pH 1.2. The reason is that drug carriers have greater swelling abilities at low pH than at high pH. The release time of drug carriers was delayed in the order of chitosan polymeric matrix, sulfonated chitosan polymeric matrix, and chitosan hydrochloride polymeric matrix. In short, the fomulation allows polymeric matrix to supress the burst effect of the drug release mechanism, which led to the controlled release pattern by swelling.
Contents of GABA and free amino acid of germinated seomocktae(Rhynchosia nulubilis) treated by low molecular weight soluble chitosan(LMSC) were investigated. Seomocktae was germinated to 2 m-length root at 20oC after presoaking in 0.05% LMSC(1, 3, 5, 10 kDa) solution for 4hr. Total free amino acid content of 5 kDa chitosan-treated group was higher than those of control and the other group, also total esential amino acid content in all chitosan-treated group was higher than those of control. Arginine(Arg), tyrosine(Tyr), valine(Val), methionine(Met), tryptophan(Trp) contents in treated group were higher than those of control. Especially, 5 kDa chitosan of various molecular weight of chitosan was highest content which showed in Arg(331 mg%),Tyr(19 mg%), Val(36 mg%), Met(34 mg%), Trp(53 mg%). In the Met content, chitosan-treated group was four time than control(8 mg%), 33~34 mg% in chitosan-treated group. GABA content in chitosan-treated group was higher than that of control(19 mg%), 28 mg%(LMSC 5 kDa), 24 mg%(LMSC 10 kDa), respectively in treated group.
Chitosan, a natural nontoxic biopolymer, is produced by the deacetylation of chitin, which is a major component of the shells of crustaceans such as crab, shrimp, and crawfish. It has various bioactivities such as reduction of cholesterol, anticancer, immunity enhancement, woundhealing and antimicrobial effect. Thus, chitosan has received considerable attention for its commercial applications in the biomedical field, food, and chemical industries. But, chitosan is limited the application in various fields because of its poor solubility in water or organic solvent. To overcome this problem, we were developed low molecular weight water-soluble chitosan (LMWSC) for improved water solubility and bioactivity. In addition, we were prepared chitosan/herbal honey composite (AMCH) for reduction of atopic dermatitis (AD). And then, we evaluated the effects of AMCH on a mouse model of AD and found that it had a reducing activity in atopic phenomenon.
Chitin, a linked by β (1→4) bonds, is the main component in the cuticles of crustaceas, insects, and mollusks and in the cell walls of some microorganisms. In the nature, three different crystalline polymorphic forms of chitin exit under natural conditions. These forms differ in the packing and polarity of the GlcNAc chains. The most abundant, α-chitin, where chains are antiparral, is present in arthropods, fungi and cysts of Entamoeba; β-chitin, made of parrallel chains. has been identified in the pen of the squid Loligo. In the third form, γ-chitin, two chains would run in one direction, and another in the opposite direction. This form has been reported in cocoon fibers of the beetle ptinus and the stomach of Loligo. In this study, α, β, γ-chitin was isolated from crab shell, squid pen, and beetles of cuticles by treatment with dilute NaOH solution for deprotenization, followed by treatment with dilute HCl solution for demineralization, and physicochemical properties investigated.
This study introduced the novel colon targeting drug delivery system as preparing the microspheres loaded drug using low molecular water soluble chitosan(LMWSC). This LMWSC microspheres are a suitable device for pharmaceutical application because of theirs biodegradable, biocompatibility, and mucoadhesive characteristics. The LMWSC was prepared by acid decomposition with high molecular insoluble chitosan. And then the WSC microspheres were prepared by crosslinking agent, glutaradehyde, chitosan aqueous in liquid paraffin oil contained emulsifier, span80. The morphology of the LMWSG microspheres which were prepared according to amounts of cross-linking agent was observed by a scanning electron microscopy(SEM). This LMWSC microspheres were prepared by loading drug, Norfloxacin(NFx). In vitro, the biodegradable experiment was carried out in phosphate buffered saline(PBS, 0.1M, pH 7.4) at 37±0.5℃. It was observed that the biodegradability was influenced by amounts of cross-linking agent.
In this study, low molecular and water soluble free-amine chitosan(LM-WSFC) was prepared to use as the carriers of drug or gene and its characterization was investigated using spectroscopic analysis method. Resultantly, the character of the pure LM-WSFC was quantitatively analyzed by these results. Also, LM-WSFC prepared in this experiment is highly water soluble, and can form complex with pasmids in physilogical buffer because of its high positive charges and low toxicity to cells. Through the experiments on the potential as gene carrier of LM-WSFC, it was showed that LM-WSFC is non-toxic and has higher transfection efficiency than poly-L-lysine (PLL). Therefore, LM-WSFC will be useful in the development of safe gene carriers.
In this study, the drug release behaviors of low molecular water soluble chitosan(LMWSC) microspheres was investigated. The LMWSC microspheres having good spherical geometry and a smooth surface were prepared by crosslinking agent, glutaraldehyde, chitosan aqueous in liquid paraffin oil contained emulsifier, span80. This LMWSC microspheres were prepared by loading drug, Norfloxacin(NFx). In vitro, the release experiment was carried out in phosphate buffered saline (PBS, 0.1M, pH 7.4) at 37±0.5℃. The release kinetic of NFx was governed not only amounts of cross-linking agent but also drug contents and particle size parameter. Resultantly, the higher amounts of cross-linking agent, the higher drug contents and the larger particle size resulted in slower the drug release.
방출조절성 약제를 개발하기 위한 방법으로 1-ethyl-6-fluoro-1, 4-dihydro-4-oxo-7-(1-piperazinyl) quinoline-3-carboxylic acid의 C₃ 위치를 Vilsmeier reagent로 chlorination하여 이를 dextran과 반응시켜 1-ethyl-6-fluoro-1, 4-dihydro-4-oxo-7-(1-piperazinyl) quinoline-3-carboxylic acid-dextran 중합체약을 합성하였다. 중합체약에 대한 최소 발육저지농도(MICs)로서 Gram 양성세균 Bacillus subtillis ATCC 6633, Staphyloccus aureus ATCC 25923, Mycrobacterium phlei IFO 3158 및 Salmonella typhimurium KCTC 1925에 대해서 각각 5 ㎍/㎖의 농도로 균의 발육을 억제하였다. Micrococcus luteus ATCC 9341에 대해서는 80 ㎍/㎖로 약한 활성을 보였을 뿐, Gram 양성세균들에 대하여 전반적으로 강한 저항성을 보여주었다. Gram 음성세균인 Escherichia coli KCTC 1039, Escherichia coli ESS, Klebsiella pueumouiae KCTC 1560 및 Pseudomonas aeruginosa IFO 13130 균주들에 대해서도 각각 5㎍/㎖로 대조물질과 유사한 항균성을 보여 주었다. 한편, quinolone계 항균제가 진균류에 대하여 감수성을 보이지 않는 것처럼 중합체약도 진균인 Candida albicans ATCC 10231에 대해서는 감수성을 보여주지 않았다. 1-Ethyl-6-fluoro-1, 4-dihydro-4-oxo-7-(1-piperazinyl) quinolinea-3-car-boxylic acid-dextran was synthesized by the reaction of 1-ethyl-6-fluoro-1, 4-dihydro-4-oxo-7-(1-piperazinyl)quinoline-3-acryloyl chloride with dextran. Polymeric drug was tested for antimicrobial activity in vitro against ten species of microorganisms. Polymeric drug revealed good antibacterial activity against Bacillus subtillis ATCC 6633, Staphyloccus aureus ATCC 25923, Mycrobacterium phlei IFO 3158, Salmonella typhimurium KCTC 1925, Escherichia coli KCTC 1039, Escherichia coli ESS, Klebsiella pueumouiae KCTC 1560 and Pseudomonas aeruginosa IFO 13130. Polymeric drug have no antimicrobial against Candida albicans ATCC 10231, but moderately active Micrococcus luteus ATCC 9341.