표면전하가 CoenzymeQ10 liposome의 물리화학적 성질과 약물동력학에 미치는 영향 = Effect of Surface Charge on the physicochemical properties and pharmacokinetic parameters of Liposome Containing CoenzymeQ10

국문 초록 (Abstract)

실험목적. 표면전하가 CoenzymeQ10 (CoQ10)을 함유하는 liposome의 물리화학적성질과 약묵동력학에 어떤 영향을 주는지 조사하기 위하여 연구를 진행하였다.
실험방법. Liposome은 Phospholipon 85G (PL)와 cholesterol 그리고 CoQ10으로 만들어졌다. Dioleoyl-trimethylammonium-propane (DOTAP)은 양이온성지질로서, dimyristoyl glycerophosphate (DMPA)은 음이온성 지질로서 사용되었다. Liposome의 물리화학적성질의 연구는 크기를 측정하고 봉입효율을 계산하며 안정성을 시험하는 방법으로 진행되었다. 안정성 시험은 각각의 온도, 빛, pH의 조건에서 실행되었다. 약물동력학실험은 쥐에게 CoQ10의 liposome 제형을 경구투여한 후, 혈장속의 CoQ10의 농도를 HPLC로 분석하는 방법으로 진행되었다.
결과. 세가지 liposome의 크기는 1 μm보다 작았다. 봉입효율의 측정결과 anionic liposome은 약 68%, neutral liposome과 cationic liposome은 약 41 %의 효율은 기록했다. 전하를 가진 liposome은 온도의 조건에서 안정성이 neutral liposome에 비해 약간 더 좋았으나 큰 차이는 없었다. 빛에 대한 안정성은 neutral liposome이 전하를 가진 liposome에 비하여 약간 더 좋았으나 역시 큰 차이는 없었다. PH에서의 안정성시험에서도 표면전하의 효과를 찾아볼 수 없었다. 전하를 가진 liposome에 비하여, CoQ10이 neutral liposome으로서 쥐에게 경구투여 되었을 때, AUC와 Cmax에서의 큰 증가를 확인할 수 있었다
결론. 안정성 시험에서 표면전하의 효과는 크게 없었다. liposome의 크기는 neutral liposome이 가장 컸으며, 봉입효율은 anionic liposome이 가장 컸다. 약물동력학 실험에서, neutral liposome이 약물전달시스템을 고려했을 때, 가장 적합한 liposome제형이라고 생각된다.

다국어 초록 (Multilingual Abstract)

Purpose. To investigate the effect of surface charge on the physicochemical properties and pharmacokinetic parameters of liposomes containing Coenzyme Q(CoQ10).
Method. Three different liposomes (neutral, cationic, and anionic) containing CoQ10 were prepared using Phospholipon 85G (PL) and cholesterol. Dioleoyl-trimethylammonium-propane (DOTAP) or dimyristoyl glycerophosphate (DMPA) were also added for charge-bearing liposomes in addition to PL and cholesterol. Physicochemical properties were evaluated in terms of particle size, entrapment efficiency, and stability (light, temperature, pH). Pharmacokinetic parameters were studied after oral administration of the liposomal formulations to Sprague-Dawley rats, and measurement of CoQ10 was performed by HPLC.
Result. Particle size of the three liposomes was less than a micron. Entrapment efficiency was about 46% in anionic liposome while it was about 28% in both neutral and cationic liposomes. Charged liposomes were more stable than neutral liposome at temperature condition but there was significant difference. Stability of CoQ10 against light was slightly improved in neutral liposome comparison with cationic and anionic liposome. However, there was no significant charge effect among them. Stability of CoQ10 in the liposomal formulation did not differ in pH tested. When CoQ10 was administered to the rats as neutral liposome, there were significant increases in AUC and Cmax compared to cationic and anionic liposome.
Conclusion. Charged liposomes of CoQ10 slightly improved stability of CoQ10 against temperature but there was no significant surface charge effect. Neutral liposome had the largest size and anionic liposome had the largest entrapment efficiency among them. In pharmacokinetic test, neutral liposome had significant increases of AUC and Cmax compared to charged liposomes.

목차 (Table of Contents)

• Ⅰ. Introduction 1
• 1. CoenzymeQ10 1
• 2. Liposome 3
• 3. Objective 5
• Ⅱ. Method 6
• 1. Reagents 6
• 2. Materials 7
• 3. Preparation of liposome containing CoQ10 9
• 4. HPLC analysis condition 9
• 5. Measurement of size and charge 9
• 6. Entrapment efficiency 9
• 7. Stability test 9
• 7.1. Effect of temperature 10
• 7.2. Effect of pH 10
• 7.3. Effect of light 10
• 8. Pharmacokinetic study 11
• 8.1. Animals 11
• 8.2. Experimental protocol 11
• 8.3. Determination of CoQ10 11
• 8.4. Data analysis 12
• Ⅲ. Result and Discussion 13
• 1. Size of liposomes 13
• 2. Zeta potential of liposomes 13
• 3. Entrapment efficiency 15
• 4. Temperature stability 17
• 5. Light stability 20
• 6. PH stability 23
• 7. Pharmacokinetic study 26
• Ⅳ. Conclusion 28
• Ⅴ. Reference 29