폴리락티드 - 글리콜리드 마이크로피어에 봉입된 단백질의 항원성 평가

송세현(Seh Hyon Song),조성완(Seong Wan Cho),신택환(Taek Hwan Shin),윤미경(Mi Kyoung Yoon),최영욱(Young Wook Choi) 한국약제학회 2001 Journal of Pharmaceutical Investigation Vol.31 No.3

N/A Biodegradable polymeric microspheres were studied for their usefulness as carriers for the delivery of vaccine antigens. However, protein antigen could be denatured during microencapsulation processes due to the exposure to the organic phase and stress condition of cavitation and shear force. Therefore this study was carried out to re-evaluate the degree of protein denaturation during microencapsulation with poly(lactide-co-glycolide) (PLGA) copolymer. PLGA microspheres containing ovalbumin (OVA), prepared by W/O/W multiple emulsification method, were suspended in pH 7.4 PBS and incubated with shaking at 37.5℃. Drug released medium was collected periodically and analyzed for protein contents by micro-BCA protein assay. In order to evaluate the protein integrity, release medium was subjected to the analyses of SDSPAGE and size exclusion chromatography (SEC). And enzyme-linked immunosorbent assay (ELISA) was introduced to measure the immunoreactivity of entrapped OVA and to get an insight into the three-dimensional structure of epitope. The structures of entrapped protein were not affected significantly by the results of SDS-PAGE and SEC. However, immunoreactivity of released antigen was varied, revealing the possibility of protein denaturation in some microspheres when it was evaluate by ELISA method. Therefore, in order to express the degree of protein denaturation, antigenicity ratio (AR) was obtained as follows: amount of immunoreactivity of OVA/total amount of OVA released × 100(%). ELISA method was an efficient tool to detect a protein denaturation during microencapsulation and the comparison of AR values resulted in more accurate evaluation for immunoreactivity of entrapped protein.

생체시료 중 실로스타졸의 분석조건 설정 및 실로스타졸 제제의 생물학적동등성

신택환,우혜승,전현주,박혜숙,최영욱 중앙대학교 약학연구소 2001 약학 논총 Vol.15 No.-

Cilostazol has both antithrombotic and cerebral vasodilating effects, and one of the mechanism is the selective inhibition of platelet cyclic AMP phosphodiesterase. A fast short-step and simple method for determining of cilostazol in human plasms has been developed and validated. The procedure was linear in the range from 0.05 to 2ug/ml for cilostazol. The intraday and interday validation for coefficient of variance (CV, %) and relative error (RE) were less than ±15%. Based on this analysis method, the bioequivalence of two cilostazol tablets, Pletaal^TM and Stazol^TM was evaluated according to the guidlines of Korea Food and Drug Administration (KFDA). Sixteen healthy male volunteers, 64.6±5.9kg in body weight and 23.2±1.5 yr in age, were divided into two groups and a randomized 2×2 cross-over study was employed. After two tablets containing 50mg of cilostazol were orally administered, blood samples were taken at the predetermined time intervals. The concentrations of cilostazol in plasma were determined by liquid-liquid extraction method using HPLC with UV detector. Pharmacokinetic parameters such as AUC, C_max and T_max were calculated and ANOVA was employed for the statistical analysis of the parameters. The results were revealed that the differences in AUC, C_max and T_max between two tablets were 7.903%, 1.100% and 10.654%, respectively. The power (1-β) for AUC and C_max were above than 80%. Minimum detectable differences (Δ) at α=0.1 and 1-β=0.8, and 90% confidence intervals for AUC and C_max were all less than ±20. All of the above mentioned parameters met the criteria of KFDA guidlines for bioequivalence, indicating that Stazol^TM tablet is bioequivalent to Pletaal^TM tablet.

생분해성 폴리락티드/글리콜리드 미립구를 이용한 재조합 소 성장호르몬(rBST)의 지속성주사제 설계

전홍렬,이봉상,권도우,윤미경,전현주,신택환,최영욱 한국약제학회 2002 Journal of Pharmaceutical Investigation Vol.32 No.3

In order to develope a sustained release formulation of bovine somatotropin(BST), which has been used to increase the body weight of oxen or the milk production of dairy cows, poly(D,L-lactide-co-glyceride)(PLGA) microspheres were made by W/O/W multiple emulsification method and solvent extraction method. Physical properties including particle size, drug entrapment, drug release, protein denaturation, and in vivo body weight increase in rats were characterized. The size of the microspheres was increased as the molecular weight of PLGA increased. When Span 65 and stearic acid during preparation were added, the size was decreased but the amount of surface protein was increased, resulting in a high loading efficiency, with fast release of BST from the microspheres. Aggregation of fragmentation of BST by SDS-PAGE during microspheres preparation and drug release study was not observed. Body weight of Sprague-Dawley's male rats was significantly increased after subcutaneous administrations of BST-loaded PLGA microspheres. There was a good correlation between in vivo weight gain and vitro release rate of microspheres. PLGA microspheres with a high surface protein ratio could be a good candidate for the sustained delivery of BST.

친수성 폴리머 제피를 이용한 말레인산암로디핀 정제의 안정성 개선

최인식,신택환,최성업,이재휘,최영욱 한국약제학회 2004 Journal of Pharmaceutical Investigation Vol.34 No.5

New formulations of amlodipine maleate tablet have been investigated to enhance the stability of the drug against light and humidity. Three kinds of amlodipine maleate tablets were prepared. One is prepared by previously known formulation (formulation C), the others were by new formulations using hydrophilic polymer (Opadry?) coated granules (formulations A and B). Amlodipine maleate powder was coated with Opadry? to produce the coated granules and it was mixed with other excipients to produce the tabletting mass of new formulations A and B. Dissolution rate of newly formulated tablets was over 80% within 10 minutes in 0.01 M HC1 medium, and its dissolution pattern was similar to that of Norvasc? tablet. After 6 months storage under accelerated conditions, residual drug contents of tested formulations (A and B) were not significantly different from formulation C, ranging from 96.2 to 100.4%. Meanwhile, dissolution amount of formulation C was significantly reduced compared to that of formulation A (p<0.05), showing formulation A was more stable than unprotected formulation C at the accelerated conditions. Results of appearance, hardness and disintegration remained unchanged during stability study. In conclusion, it showed that the new formulations had enhanced the stability characteristics and hydrophilic coating technique was an alternative and promising method to improve the stability of amlodipine maleate tablet.

혈장 중 트리플루살의 분석조건설정 및 트리플루살 제제의 생물학적 동등성

우혜승,신택환,전호성,최성업,이상길,조성완,최영욱 중앙대학교 약학연구소 2000 약학 논총 Vol.14 No.-

Triflusal is an inhibitor of platelet aggregation structurally related to the salicylate group. Triflusal and its active metabolite 2-hydroxy-4-trifluoromethyl benzoic acid (HTB) have platelet antiaggregant effect. A fast short-step and simple method for determining of triflusal in human plasma has been developed and validated. The procedure was linear in the range from 0.1 to 5 ug/ml for triflusal. The intraday and interday validation for coefficient of variance (CV, %) and relative error (RE) were less than ±15%. Based on this analysis method, the bioequivalence of two triflusal capsules, Disgren^TM and Tris^TM was evaluated according to the guidlines of Korea Food and Drug Administration (KFDA). Sixteen healthy male volunteers, 66.25±6.82kg in body weight and 23.25±1.48 in age, were divided into two groups and a randomized 2×2 cross-over study was employed. After one capsule containing 300mg of triflusal was orally administered, blood samples were taken at the predetermined time intervals and the concentrations of triflusal in plasma were determined by protein precipitation method using HPLC with UV detector. Pharmacokinetic parameters such as AUC, C_max and T_max were calculated and ANOVA was employed for the statistical analysis of parameters. The results were revealed that the differences in AUC, C_max and T_max between two capsules were 2.58%, -0.74% and 17.09%, respectively. The power (1-β) for AUC and C_max were above than 80%. Minimum detectable differences (Δ) at α=0.1 and 1-β=0.8 and 90% confidence intervals for AUC and C_max were all less than ±20. All of the above mentioned parameters met the criteria of KFDA guidlines for bioequivalence, indicating that Tris^TM capsule is bioequivalent to Disgren^TM capsules.