• 한국섬유공학회:학술대회논문집
• /
• 한국섬유공학회 2002년도 봄 학술발표회 논문집
• /
• pp.29-32
• /
• 2002

Thermodynamics of copolymerization is one of the fundamental elements for studying the effects of copolymerization parameters on the copolymer characteristics. Up until now, it has not been easy work not because there are not effective models but because the known thermodynamic values are limited to some copolymer pairs. Recently, owing to the development of molecular modeling methods, some thermodynamic parameters can be calculated and estimated on computer. (omitted)

• Journal of Pharmaceutical Investigation
• /
• 제18권2호
• /
• pp.49-53
• /
• 1988

Pivaloyloxymethyl ester of piperacillin was synthesized by reacting sodium piperacillin with chloromethyl pivalate, and its chemical structure was determined by infrared and $^1H$ nuclear magnetic resonance spectroscopic methods. The pharmaceutical properties of the ester were investigated to assess its potential as a novel prodrug of piperacillin. The interface transfer of piperacillin and the ester was studied in a two-phase in vitro system composed of aqueous pH buffers and n-octanol. The ester was more lipophilic, and less water soluble above pH 4.0 than piperacillin. Significant antibacterial activity was not observed in the ester in vitro, but the ester was hydrolyzed into the parent drug in the rat liver homogenate. The serum levels of orally administered ester suspension containing 0.1% Tween 80 were measured in rabbits. It was found that the ester showed higher blood level, comparing with no observation of piperacillin in serum, but the time reaching the maximum serum concentration was 5 hr.

• 한국임상수의학회:학술대회논문집
• /
• 한국임상수의학회 2008년도 춘계학술대회
• /
• pp.83-83
• /
• 2008

• 한국섬유공학회:학술대회논문집
• /
• 한국섬유공학회 2003년도 가을 학술발표회 논문집
• /
• pp.104-107
• /
• 2003

Poly(vinyl alcohol) (PVA) obtained by the saponification of poly(vinyl ester) like poly(vinyl acetate) o. poly(vinyl pivalate) is a linear semicrystalline polymer, which has been widely used as fibers for clothes and industries, films, membranes, medicines for drug delivery system, and cancer cell-killing embolic materials[1-3]. PVA fibers and films have high tensile and compressive strengths, high tensile modulus, and good abrasion resistance due to its highest crystalline lattice modulus. (omitted)

• Journal of Pharmaceutical Investigation
• /
• 제18권4호
• /
• pp.197-201
• /
• 1988

Pivaloyloxymethyl ester of cefoperazone was synthesized by treating sodium cefoperazone with chloromethyl pivalate and its chemical structure was determined by spectroscopic trials. The pharmaceutical properties of the ester were investigated to assess its potential as a prodrug of cefo perazone. Cefoperazone pivaloyloxymethyl ester was microbiologically inactive itself in vitro, but hydrolyzed into the parent drug in vivo. After a single oral dose of each drug to rabbits, serum concentrations of cefoperazone were determined by high performance liquid chromatographic assay. The ester showed higher and more sustained blood level than cefoperazone. Therefore, the total area under the serum concentration-time curve of the derivative was 16.8 times larger than that of the parent drug.

• 한국임상수의학회지
• /
• 제28권2호
• /
• pp.244-248
• /
• 2011

부신피질기능저히증은 부신에서 생산되는 글루코코르티코이드와 미네랄로코르티코이드의 결핍으로 발생한다. 개에서 부신피질기능저하증을 관리하기 위해 fludrocortisone이 사용되어왔다. 그러나 desoxycorticosterone pivalate의 경우 fludrocortisone과 대등한 효과와 보호자와 환자에게 적은 부담을 주기 때문에 최근 몇 년간 부신피질기능저하증 개의 관리를 위해 사용되었다. 임상증상, 전해질불균형, adrenocorticotropic hormone stimulation test를 통하여 부신피질 기능저하증으로 진단된 14마리의 개에서 DOCP의 효과를 분석하였다. DOCP의 초기용량은 2.2 mg/kg 으로 사용되었으며 25일 간격으로 근육 또는 피하로 주사되었다. DOCP의 효능을 보기 위해 25일 간격으로 임상증상, 혈청 전해질 수치, 혈청 요소질소, 크레아티닌 수치를 모니터링 하였다. Fludrocortisones은 개에서 효과적인 치료법이지만 부작용과 불충분한 반응으로 7마리의 개에서 DOCP로의 전환이 필요하였다. 7마리의 개는 처음부터 DOCP가 투약되어 총 14마리의 개가 DOCP로 관리 받았다. 12마리의 개에서 임상증상, 전해질 불균형이 완전히 해소되었으나 2마리의 개에서는 몸 떨림과 같은 약간의 임상증상이 여전히 남아있었다. 4마리의 개는 프레드니손의 정기적 투여가 필요하였다. 이러한 결과를 종합해 보면, fludrocortisone과 비교하여 DOCP가 임상증상과 전해질불균형의 개선에 훨씬 효과적이었으며 이 결과는 부신피질기능저하증 개에서 DOCP가 더 좋은 치료법임을 제시해준다.

• Journal of Pharmaceutical Investigation
• /
• 제22권2호
• /
• pp.139-148
• /
• 1992

A prodrug of cefazolin pivaloyloxymethyl ester (CFZ-PV) was synthesized to improve oral absorption and bioavailability of parent drug by esterification of sodium cefazolin (CFZ) with chloromethyl pivalate. The successful synthesis of CFZ-PV was confirmed by spectroscopic analysis. Partition coefficient studies showed that CFZ-PV is more lipophilic than CFZ. The pharmacokinetic characteristics of CFZ-PV and CFZ preparations were compared following oral administrations of these compounds to rabbits. The analysis of CFZ in plasma was conducted by HPLC method. The ester compound (prod rug) was not detected in plasma following oral administration of CFZ-PV, and although CFZ-PV had not microbiological activity in vitro, the plasma taken after CFZ-PV administration had microbiological activity. From above observations, it was noted that CFZ-PV is rapidly hydrolyzed to CFZ in the body. And it was found that the oral absorption of CFZ-PV was increased, yielding 2-fold higher bioavailability than CFZ. From the results of this experiment, it was concluded that CFZ-PV could be a novel prodrug of CFZ which can improve the oral bioavailability of CFZ.

• Journal of Pharmaceutical Investigation
• /
• 제25권4호
• /
• pp.323-330
• /
• 1995

Ceftezole pivaloyloxymethyl ester(CFZ-PV) was synthesized to improve oral absorption and bioavailability of parent drug by esterification of ceftezole(CFZ) with chloromethyl pivalate. The successful synthesis of CFZ-PV was conformed by spectroscopic analysis. Partition coefficient studies showed that CFZ-PV is more lipophillic than CFZ. The pharmacokinetic characteristics of CFZ-PV and CFZ were compared following oral administrations of these compounds to rabbits. The amount of CFZ in plasma was determined with an HPLC method. The ester compound (prodrug) was not detected in plasma following oral administration of CFZ-PV, and although CFZ-PV had not microbiological activity in vitro, the plasma taken after oral administration of CFZ-PV had microbiological activity. From above observations, it was noted that CFZ-PV is rapidly hydrolyzed to CFZ in the body. And the oral absorption of CFZ-PV was increased by yielding 2-fold bioavailability rather than CFZ. Therefore, CFZ-PV could be a novel prodrug of CFZ which can improve the oral bioavailability of CFZ.

• 폴리머
• /
• 제37권4호
• /
• pp.486-493
• /
• 2013

고분자 색전 코일을 제조하기 위하여 교대배열 PVA(s-PVA) 용액을 제조하고 젤방사 조건의 최적화를 위해 고분자용액의 유변학적 특성을 분석하였다. 현탁중합을 통해 비누화도 99%, 교대배열기 함량 56%인 s-PVA를 제조하였고 고분자 용액의 농도에 따른 점도 변화 측정을 통해 최적의 방사농도를 13 wt%로 선정하였다. S-PVA 젤 섬유의 연신비에 따른 구조, 형태, 인장 특성을 측정하였다. S-PVA 젤 섬유의 연신비가 증가함에 따라 인장강도가 증가하였고, 최대 연신비인 15배 연신하였을 때 인장강도는 580 MPa이었고 절단신도는 연신비가 증가함에 따라 감소하는 경향을 나타냈다. S-PVA 젤 섬유는 연신비에 따라 결정구조가 발달하고 배향도가 증가하는 경향을 나타내었다. 색전 코일 제조 시의 열처리온도에 따른 코일의 형태 안정성을 살펴 본 결과 열처리온도가 높을수록 코일의 형태안정성이 우수하였으며 금속 색전 코일로 제조되는 1차 코일 및 2차 코일 형태를 s-PVA 섬유를 이용해 제조하였고 이를 통해 금속 색전 코일의 고분자로의 대체 가능성을 확인하였다.