Abstract
Abstract: :
Purpose:To analyze samples of seven different silicone oils that have been used for intraocular injection in respect to the differences in their molecular weight distribution and low molecular weight components using gel permeation chromatography. Methods:Distribution of molecular weight of seven samples of different silicone oils was evaluated using gel permeation chromatography analysis with a Shimadzu Class-LC10 and a Shimadzu refractive index detector. The molecular weight distribution was calculated by a gel permeation chromatography/SEC software based on polystyrene calibration standards. The samples were dissolved in tetrahydrofurane and analyzed with Supelco Progel TSK-HLX (1xG5000 + 1XG4000 + 1xG3000) columns for tetrahydrofurane. Results:The average number of the samples and the weight average of the samples were calculated by using polystyrene standards. Table reveals the molecular weight distribution and the polydispersity of the silicone olis. All the seven samples tested have contained various quantities of low molecular weight components. Conclusion: Gel permeation chromatography spectrum revealed that all oils underwent a fractionation process. However, the purification methods did not show to be effective for the total elimination of the low molecular weight components which may cause ocular toxicity and accelerate the emulsification of silicone oils. Further analysis should be performed to identify and determine the concentration of low molecular weight components and impurities in each sample. REFERENCES 1.CRISP, A, JUAN, E, TIEDEMAN, M. Effect of silicone oil viscosity on emulsification. Arch Ophthalmol 1987;105:546-50. 2.GABEL, VP, KAMPIC, A, BURKHARDT,J. Analysis of intraocularly applied silicone oils of various origins. Graefs Arch Clin Exp Ophthalmol 1987; 225(3):160-2. 3.HEIDENKUMMER, HP, KAMPIK, A, THIERFELDER, S. Emulsification of silicone oils with specific physicochemical characteristics. Graefs Arch Clin Exp Ophthalmol 1991;229:88-94. 4.TRATHNIGG, B. Size-exclusion chromatography of polymers, in Meyers RA(ed). Encyclopedia of Analytical Chemistry. Chichester: John Wiley &Sons;, 2000, 8008-34
Keywords: clinical (human) or epidemiologic studies: sys • clinical laboratory testing • vitreous substitutes