【正文】 溶膠凝膠轉(zhuǎn)變溫度隨 pH的增加而減少， 此外，隨著可逆性溶膠溶液的轉(zhuǎn)變溫度減低和 PEG濃度 的增加，將會(huì)有更多的眼藥類型供選擇，通過對(duì)熱固性凝膠的流變性能和大家熟知的 原位凝膠系統(tǒng) 以及 結(jié)冷膠和泊洛沙姆的解決方案 相比較，很明顯前者的解決方案和后者有明顯的不同， 其作為藥物傳遞系統(tǒng)灌輸?shù)窖鄄康挠锰?很實(shí)用。當(dāng) PEG單獨(dú)添加到 MC中時(shí) ，溶液的熱定形凝膠溫度只是略微 降低 ，但 大大 減少了檸檬酸的加入。 如圖所示 ， 當(dāng) MC（ SM 25）和 SC濃度保持恒定在 %和 %不變時(shí)，同時(shí) PEG 4000濃度的變化范圍 在 0%到 10%之間， 可逆的溶膠凝膠轉(zhuǎn)變溫度隨著 PEG濃度的增加 而 下降 。由于凝膠的熔點(diǎn)和凝固 點(diǎn)不同 ，本研究不太適合 用 落球法和 U形管方法 ， MO設(shè)置凝膠 的 凝 點(diǎn) 很重要的 一點(diǎn)是利用 DSC對(duì)溫度不敏感的 特性 。將 其 冷卻至 5℃ ，在 30ml蒸餾水中混合 SC，然后在 15ml蒸餾水溶液 中混合 400。 我們發(fā)現(xiàn)了一 種 熱固性凝膠溶 液 在甲基纖維素聚乙二醇檸檬酸三元系統(tǒng)中的應(yīng)用，并開發(fā)了一種含馬來酸噻嗎洛爾， 可以 用 來 治療青光眼的眼用溶液 ， 據(jù)報(bào)道，長(zhǎng)效的眼用溶液 的 流量曲線觸變性在 32176。中文 2726 字 可逆熱固性原位膠凝流變特性的解決方案與甲基纖維素聚乙二醇檸檬酸三元系統(tǒng) Masanobu Takeuchi Shinji Kageyama Hidekazu Suzuki Takahiro著， … ..譯 . [摘要 ] 可逆 性 溶膠凝膠 溫度的轉(zhuǎn)變受到 甲基纖維素 (MC)、聚乙二醇 (PEG)、檸檬酸 (SC) 三元體系 的影響 ， 通過流變學(xué)測(cè)量 得出 原位凝膠體系 的 性能。C ，呈現(xiàn)出粘度隨溫度升高 而 明顯變化 的特性。 攪拌該混合物直到透明。 綜合 以上考慮， 應(yīng)該使用 試管倒置法和彈性力學(xué)與流變儀測(cè)定 法 。當(dāng) PEG濃度為 10%時(shí)，溶液的粘度 在 24176。 PEG引起 了 葡聚糖水溶液的相分離 ， 此外，研究發(fā)現(xiàn)，過量添加 PEG誘導(dǎo)熱定形凝膠（ MC– PEG– SC系統(tǒng)）相分離（微相分離 ），通過 上述研究發(fā)現(xiàn) 了 PEG通過 誘導(dǎo)微相分離加速 MC形成交聯(lián) 的 解決方案。 參考文獻(xiàn) [1] Bourdais CL, Acar L, Zia H, Sado PA , Needham .Leverge R (1998) 前衛(wèi)視網(wǎng)膜眼研究 17:33 [2] Sasaki H, Nishida K, Nakamura M (1996) 前衛(wèi)視網(wǎng)膜眼研究 15:583 [3] Chrai SS. RobinsonJR (1974 ) 醫(yī)藥供應(yīng)鏈 63:1218 [4] Kurimoto K, Eguchi K, Kitajima S,Kishimoto N, Matsumoto (1991) Atarashii Ganka 8:1259 [5] Kabayama T, Suzuki H, Horiuchi T,Akutagawa Y. Matsuzaki H (1979) 日本眼科系統(tǒng) [J]. 83:326 [6]TakeuchiM,KageyamaS,SuzukiH,WadaT,ToyodaY,OgumaT,EzureY,TsuriyaY,F(1999) 材料技術(shù) 17:445 [7] Patton JR (1975) 藥學(xué)科學(xué) 64:1312 [8] Rozier A, Mazuel C, Grove J, Plazon~. B (1989) 國(guó)際藥學(xué)雜志 57:163 [9] Kato T, Yokoyama M. Takahashi A(1978) 膠體高分子科學(xué) 265:15 [10] Heymann E (1935) 反式法拉 Soc 31:846 [11] Edmond E. Ogston AG (1968) 生物化學(xué)雜志 109:569 [12] Miyoshi E .Nishinari K (1998) Kobun~shi Ronbunshu 55:567 [13] Vadnere M,AmidonG, LindenbaumS. JohnL (1984) INTJ制藥 22:207 [14] Cho CW,Shin IJ (1997) Drug DevInd Pharm 23:1227 Rheological properties of reversible thermosetting in situ gelling solutions with the methylcellulose–polyethylene glycol–citric acid ternary system Masanobu Takeuchi Shinji Kageyama Hidekazu Suzuki Takahiro Wada Yoshitada Notsu Fumiyoshi Ishii Abstract The position of vehicle on the reversible sol– gel transition temperature in a ternary system made up of methylcellulose (MC), polyethylene glycol (PEG), and citric acid (SC) was investigated. The properties of the in situ gelling system were estimated by rheological measurement. When PEG (4000) concentration was varied from 0% to 10% while MC (SM25) and SC concentrations were kept constant at % and %, respectively, the reversible sol– gel transition temperature lowered from 38 _C to 26 _C with increasing PEG concentration. However, the extent of lowering in temperature was not influenced by the molecular weight of PEG. The reversible sol– gel transition temperature shifted towards the lower temperature with increasing MC concentration, and towards the higher temperature with decreasing pH. Comparison of rheological properties between the present thermosetting in situ gelling solution and a conventional one, such as gellan gum solution or Poloxamer 407 solution, revealed that the present solution radically differed from the conventional solutions in the incipient gelling mechanism. These findings suggest that the ternary system in this study would be useful as a drug delivery system for instillation of drugs into the eye. Keywords Thermosetting gel Sol– gel transition temperature Rheology Methylcellulose– polyethylene glycol– citric acid ternary system Introduction Studies have been made to improve the poor bioavailability of ophthalmic solutions in the eye using various drug delivery systems [1, 2]. For example, polymers gain in viscosity when dissolved and this property is utilized. Thus, attempts were made to prolong the duration of effect by adding a polymer to the ophthalmic solution, thereby increasing precorneal residence time of the drug and improving the ke