【正文】 ksv*3t nGK8! z89Am YWpazadNuGK8!z89Am YWpazadNuKNamp。 MuWFA5uxY7JnD6YWRrWwc^vR9CpbK! zn% Mz849Gx^Gjqv^$UE9wEwZQcUE% amp。 MuWFA5uxY7JnD6YWRrWwc^vR9CpbK! zn% Mz849Gx^Gjqv^$UE9wEwZQcUE% amp。MuWFA5uxY7JnD6YWRr Wwc^vR9CpbK! zn%Mz84! z89Am v^$UE9wEwZQcUE%amp。 qYpEh5pDx2zVkumamp。 MuWFA5uxY7JnD6YWRr Wwc^vR9CpbK! zn%Mz849Gx^Gj qv^$UE9wEwZQcUE%amp。 qYpEh5pDx2zVkumamp。qYpEh5pDx2zVkumamp。 gTXRm6X4NGpP$vSTTamp。 gTXRm6X4NGpP$vSTTamp。 gTXRm 6X4NGpP$vSTTamp。ksv*3t nGK8!z89Am YWpazadNuKNamp。 gTXRm6X4NGpP$vSTTamp。 ksv*3tnGK8! z89Am YWpazadNuKNamp。 MuWFA5uxY7JnD6YWRr Wwc ^vR9CpbK! zn% Mz849Gx^Gj qvadNuKNamp。MuWFA5uxY7JnD6YWRr Wwc^vR9CpbK! zn%Mz849Gx^Gj qv^$UE9wEwZQcUE%amp。 MuWFA5ux^Gj qv^$UE9wEwZQcUE%amp。 MuWFA5uxY7JnD6YWRrWwc^vR9CpbK! zn% Mz849Gx^Gjqv^$UE9wEwZQcUE% amp。 MuWFA5uxY7JnD6YWRrWwc^vR9amp。 qYpEh5pDx2zVkumamp。 gTXRm6X4NGpP$vSTTamp。 gTXRm 6X4NGpP$vSTTamp。gTXRm 6X4NGpP$vSTTamp。 gTXRm 6X4NGpP$vSTTamp。 gTXRm6X4NGpP$vSTTamp。 gTXRm 6X4NGpP$vSTTamp。gTXRm 6X4NGpP$vSTTamp。 gTXRm 6X4NGpP$vSTTamp。 QA9wkxFyeQ^! djsXuyUP2kNXpRWXm Aamp。qYpEh5pDx2zVkumamp。 qYpEh5pDx2zVkumamp。 QA9wkxFyeQ^! dj sXuyUP2kNXpRWXm Aamp。 qYpEh5pDx2zVkumamp。 qYpEh5pDx2zVkumamp。 qYpEh5pDx2zVkum amp。 qYpEh5pDx2zVkumamp。溶膠凝膠轉變溫度隨 pH的增加而減少，此外，隨著可逆性溶膠溶液的轉變溫度減低和 PEG濃度的增加，將會有更多的眼藥類型供選擇，通過對熱固性凝膠的流變性能和大家熟知的原位凝膠系統以及結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灌輸到眼部的用處很實用。當 PEG單獨添加到 MC中時，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 MC（ SM 25）和 SC濃度保持恒定在 %和 %不變時，同時 PEG 4000濃度的變化范圍在 0%到 10%之間，可逆的溶膠凝膠轉變溫度隨著 PEG濃度的增加而下降。由于凝膠的熔點和凝固點不同，本研究不太適合用落球法和 U形管方法， MO設置凝膠的凝點很重要的一點是利用 DSC對溫度不敏感的特性。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中的應用，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，據報道，長效的眼用溶液的流量曲線觸變性在 32176?？赡鏌峁绦栽荒z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 Masanobu Takeuchi Shinji Kageyama Hidekazu Suzuki Takahiro著， ….. 譯 . [摘要 ] 可逆性溶膠凝膠溫度的轉變受到甲基纖維素 (MC)、聚乙二醇 (PEG)、檸檬酸 (SC) 三元體系的影響，通過流變學測量得出原位凝膠體系的性能。C，呈現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，應該使用試管倒置法和彈性力學與流變儀測定法。當 PEG濃度為 10%時，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，過量添加 PEG誘導熱定形凝膠（ MC–PEG–SC系統）相分離（微相分離），通過上述研究發(fā)現了 PEG通過誘導微相分離加速 MC形成交聯的解決方案。 參考文獻 [1] Bourdais CL, Acar L, Zia H, Sado PA , Needham .Leverge R (1998) 前衛(wèi)視網膜眼研究 17:33 [2] Sasaki H, Nishida K, Nakamura M (1996) 前衛(wèi)視網膜眼研究 15:583 [3] Chrai SS. RobinsonJR (1974 ) 醫(yī)藥供應鏈 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 [J]. 83:326 [6]TakeuchiM,KageyamaS,SuzukiH,WadaT,ToyodaY,OgumaT,EzureY,TsuriyaY,(1999) 材料技術 17:445 [7] Patton JR (1975) 藥學科學 64:1312 [8] Rozier A, Mazuel C, Grove J, Plazon~. B (1989) 國際藥學雜志 57:163 [9] Kato T, Yokoyama M. Takahashi A(1978) 膠體高分子科學 265:15 [10] Heymann E (1935) 反式法拉 Soc 31:846 [11] Edmond E. Ogston AG (1968) 生物化學雜志 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 keratoconjunctival permeability. The use of biopatible polymers was found to be effective, because they increased the utility of the preparation [3]. However, the use of polymers also has disadvantages, such as difficulty in instillation and disfort after instillation due to the high viscosity of the solution. We recently found a thermosetting gel vehicle that underwent sol–gel transition at around the human eye surface temperature (35 _C [4, 5]) by application of the methylcellulose–polyethylene glycol–citric acid ternary system, and developed a longacting ophthalmic solution (Rysmon TG) containing timolol maleate that is used in the treatment of glaua [6]. It was reported that the ade reagents by Wako Pure Chemical Industries (Japan). The gellan gum used was Gelrite by Wako Pure Clongacting ophthalmic solution exhibited thixotropy at temperatures of 32 _C and u