min in 10 ml of aqueous solutions in the ph range 1 9 and filtered the adsorption spectra of the filtered solution show that only 2 of atorvastatin was released at ph 1 while 43 of the active principle was released at ph 9 the experiment was then repeated at 36 u00b0 c keeping unchanged the other conditions the analysis of absorption spectra of the filtered solutions showed no changes in the amount of atorvastatin released at ph 1 i e 2 and 9 i e 43 250 mg of tio 2 atorvastatin carrying 83 mg of atorvastatin should allow the release of 36 mg of the drug in the intestinal region adsorption of atorvastatin calcium on tio 2 precoated with 110 undecenoic acid coating of titanium dioxide nanoparticles with the long chain carboxylic acid was performed by stirring in 50 ml of methanol 1 00 g of tio 2 with 1 ml of pure 10 undecenoic acid for 24 h the suspension was then filtered and the solid washed twice with 10 ml portions of methanol and then dried at 40 u00b0 c the infrared spectrum of the solid product clearly shows that the long aliphatic chain carboxylic acid is adsorbed on tio 2 relevant bands of the 10 undecenoic acid at ca 2924 2853 1709 1530 and 1420 cm u2212 1 are also observed for the sample adsorbed on tio 2 adsorption of atorvastatin on tio 2 nanoparticles pre coated with 10 undecenoic acid abbreviated as tio 2 und was performed by stirring for 1 h a 500 mg amount of tio 2 und in 50 ml of a methanol solution containing dissolved 250 mg of atorvastatin the suspension was then evaporated under vacuum and the solid dried at 40 u00b0 c overnight desorption of.