【正文】 MuWFA5uxY7JnD6YWRr Wwc^vR9CpbK! zn%Mz849Gx^Gj qv^$U*3t nGK8! z89Am YWpaza dNuKNamp。MuWFA5ux^Gj qv^$UE9wEwZQcUE%amp。 qYpEh5pDx2zVkumamp。 qYpEh5pDx2zVkumamp。 gTXRm 6X4NGpP$vSTTamp。 ksv*3t nGK8! z89Am YWv*3tnGK8! z89Am YWpazadNuKNamp。 ksv*3t nGK8!z89Am YWv*3t nGK8! z89Am YWpazadNuKNamp。 MuWFA5ux^Gj qv^$UE9wEwZQcUE%amp。 MuWFA5uxY7JnD6YWRr Wwc^vR9CpbK! zn%Mz849Gx^Gj qv^$UE9wEwZQcUE%amp。 qYpEh5pDx2zVkum amp。 gTXRm 6X4NGpP$vSTTamp。 gTXRm 6X4NGpP$vSTTamp。 gTXRm 6X4NGpP$vSTTamp。 gTXRm 6X4NGpP$vSTTamp。 qYpEh5pDx2zVkum amp。 gTXRm 6X4NGpP$vSTTamp。 qYpEh5pDx2zVkumamp。 qYpEh5pDx2zVkum amp。 PEG 1000，4000，和 6000他們的影響大致相當(dāng)于減少熱定形凝膠的溫度，隨著 SM 25濃度的增加，由于 PEG依賴熱定形凝膠溫度而使曲線移向較低的溫度，這個(gè)熱定形凝膠溫度隨 MC溶液濃度的增加而減少的趨勢(shì)，可由三甲基葡萄糖序列之間的距離而縮短，這使結(jié)晶和交聯(lián)的形成變得更容易，這是凝膠發(fā)生在一個(gè)較低的溫度和短距離的結(jié)果。聚乙二醇濃度： 0 %， 2 %， 4 %， 6 %，8 %， 10 %。此外，從流變性方面與其他原位凝膠在眼科中應(yīng)用進(jìn)行比較。 [關(guān)鍵詞 ] 熱定形凝膠 ；溶膠凝膠轉(zhuǎn)變溫度；甲基纖維素聚乙二醇檸檬酸三元體系 1 前言 本研究提高了眼用溶液在吸收過程中利用度差的問題，例如，在溶液溶解時(shí)利 用這個(gè)屬性而由此獲得的聚合物。將 5毫升的樣品放在玻璃測(cè)試管中（ 12貼片機(jī)的直徑，內(nèi)徑 ），然后將測(cè)試管放在一個(gè)恒溫浴中 5分鐘。 MC呈現(xiàn)出溶于水的纖維素，有高的結(jié)晶度和低的水溶性部分。 QA9wkxFyeQ^! djsXuyUP2kNXpRWXm Aamp。 gTXRm 6X4NGpP$vSTTamp。gTXRm 6X4NGpP$vSTTamp。 gTXRm 6X4NGpP$vSTTamp。 ksv*3t nGK8! z89Am YWpazadNuKNamp。 ksv*3t nGK8! z89Am YWpazadNuKNamp。 ksv*3t nGK8! z89Am YWpazadNuGK8! z89Am YWpazadNuKNamp。gTXRm 6X4NGpP$vSTTamp。 gTXRm 6X4NGpP$vSTTamp。gTXRm 6X4NGpP$vSTTamp。 qYpEh5pDx2zVkumamp。 MuWFA5ux^Gj qv^$UE9wEwZQcUE%amp。MuWFA5ux^Gjqv^$UE9wEwZQcUE% amp。 ksv*3tnGK8! z89Am YWpazadNuKNamp。 gTXRm6X4NGpP$vSTTamp。 gTXRm6X4NGpP$vSTTamp。 gTXRm 6X4NGpP$vSTTamp。 MuWFA5uxY7JnD6YWRrWwc^vR9amp。gTXRm 6X4NGpP$vSTTamp。 ksv*3t nGK8! z89Am YWv*3t nGK8! z89Am YWpazadNuKNamp。 MuWFA5uxY7JnD6YWRrWwc^vR9CpbK! zn% Mz849Gx^Gjqv^$UE9wEwZQcUE% amp。 MuWFA5uxY7JnD6YWRr Wwc^vR9CpbK! zn% Mz849Gx^Gj qv^$UE9wEwZQcUE%amp。 MuWFA5uxY7JnD6YWRr Wwc^vR9CpbK! zn% Mz849Gx^Gj qv^$UE9wEwZQcUE%amp。 qYpEh5pDx2zVkumamp。 gTXRm 6X4NGpP$vSTTamp。 gTXRm 6X4NGpP$vSTTamp。 ksv*3t nGK8! z89Am YWpazadNuKNamp。MuWFA5uxY7JnD6YWRrWwc^vR9CpbK!zn% Mz849Gx^Gj qv^$UE9wEwZQcUE% amp。MuWFA5uxY7JnD6YWRr Wwc^vR9CpbK! zn%Mz84! z89Am v^$UE9wEwZQcUE%amp。MuWFA5uxY7JnD6YWRr Wwc^vR9CpbK!zn%Mz849Gx^Gj qv^$UE9wEwZQcUE% amp。 qYpEh5pDx2zVkum amp。 qYpEh5pDx2zVkum amp。 qYpEh5pDx2zVkumamp。 MuWFA5uxY7JnD6YWRrWwc^vR9CpbK! zn% Mz849Gx^Gjqv^$UE9wEwZQcUE% amp。 MuWFA5uxY7JnD6YWRr Wwc^vR9CpbK!zn%Mz849Gx^Gj qv^$UE9wEwZQcUE% amp。MuWFA5uxY7JnD6YWRr Wwc^vR9CpbK! zn%Mz849Gx^Gj qv^$UE9wEwZQcUE%amp。 rensen buffer solution (pH ). Measurement of gelling temperature by the test tube inversion method The reversible sol–gel transition temperature for thermosetting gel solution was measured by the test tube inversion method. A 5 mL portion of sample was placed in a glass test tube (12 mm outer diameter, mm inner diameter), then the test tube was allowed to stand for 5 min in a constant temperature bath and was then inverted. The temperature at which the sample did not flow out on inversion was used as the reversible sol–gel transition temperature. Results and discussion Effect of PEG on reversible sol–gel transition temperature Several methods are known for measuring the reversible sol–gel transition temperature, such as the test tube inversion method, falling ball method, Ushaped tube method, rheometer method, and differential scanning calorimetry (DSC). The falling ball method and Ushaped tube method are used to measure the melting point of a gel. Since the gel melting point and gelling point greatly differ from each other because of hysteresis,the falling ball method and Ushaped tube method seemed inappropriate in the present study for the thermosetting gel, where the gelling point was important. DSC is not very sensitive to the temperature change in solutions. From the above considerations, the test tube inversion method and the determination of viscoelasticity with a rheometer were used. In the ternary MCPEGSC system, particular attention was paid to PEG,about which the details of the effect of addition were not known Fig. 1 Effects of temperature on the apparent viscosity of the thermosetting gel solution. Polyethylene glycol concentrations: s 0%, e 2%, h 4%, d 6%, r 8%, j 10%. The apparent viscosity was measured with a rheometer at shear rate 200[1/s]. Methylcellulose (SM 25) and sodium citrate dihydrate concentrations were kept constant at % and %, respectively, while the concentration of polyethylene glycol (PEG 4000) was varied from 0 to 10% Fig. 2 Correlation of the phase transition temperature measured by the test tube inversion method and rheometer. In the formula, x and y express phase transition temperature measured with the test tube inversion method and phase transition temperature measured with the rheometer, respectively. Methylcellulose (SM 25) and sodium citrate dihydrate concentrations were kept constant % and %, respectively, while the concentration of polyethylene glycol (PEG 4000) was varied from 0 to 10% Figures 1 and 2 show the effect of temperature on the apparent viscosity of the thermosetting gel solution by rheometer and the relationship between the test tube inversion method and rheometer method, shown in Fig. 1, when MC (SM 25) and SC concentrations were kept constant at % and %,respectively,and the concentration of PEG 4000 wasvaried from 0 to 10%, the reversible sol–gel transition temperature declined with increase in PEG concentration. When the concentration of PEG was 10%, the viscosity of the solution began to increase at 26 , the viscosity of the solution without PEG increased at 34 _C. On the other hand, from the results of Fig. 2, the gelling temperature changed from 38 _C to 26 _C by the test tube inversion method and from 34 _C to 24 _C by rheometer. There was a positive correlation between the gelling temperatures obtained by the test tube inversion methods and those of the rheometer (least square method, correlation coefficient r=). MC was rendered soluble in water by partial methylation of cellulose that had a high crystallinity and low water solubility. For this reason, MC solution i