Study On The Charge Transfer Reaction Of Carvedilol, Irbesartan And Timolol Maleate

Objective: To propose a Charge Transfer-Ultraviolet Spectrophotometry method for fast determinating of Carvedilol, Irbesartan, and Timolol Maleate in preparations and serum. Methods: The charge transfer reaction between Irbesartan, Carvedilol, Timolol Maleate as electron donors and an appropriate electron acceptor has been studied by spectrophotometric method; the optimum reaction conditions have been optimized and established. Results:(1)Optimal reaction condition of charge transfer reaction between Carvedilol and alizarin: the Carvedilol can react with alizarin to form 1:1 complex after being placed in the room temperature for 30 minutes, which gives a maximum absorption peak at 542 nm, the linear range was 5-180mg/L, r = 0.9999. If used in the determination of Carvedilol for capsule and tablet, the recovery was between 99.4% and 101.0%. If used in the determination of Carvedilol in serum, the recovery was between 101.1% and 101.4%.(2)Optimal reaction condition of charge transfer reaction between Irbesartan and chloranilic acid: the Irbesartan can react with chloranilic acid to form 1:1 complex at once, which gives a maximum absorption peak at 520 nm, the linear range was10-800mg/L, r = 0.9999. If used in the determination of Irbesartan for capsule and tablet, the recovery was between 100.3% and 101.6%. If used in the determination of Irbesartan in serum the recovery was between 99.7 % and 100.05%.(3)Optimal reaction condition of charge transfer reaction between Timolol Maleate and TCNQ: the Timolol Maleate can react with TCNQ to form 1:1 complex after being placed in the 50℃ water bath for 60 minutes, which gives a maximum absorption peak at 842 nm, the linear range was1-25mg/L, r = 0.9990. If used in the determination of Timolol Maleate for eye drops and tablets the recovery was between 100.4 and 102.2%. If used in the determination of Timolol Maleate in serum the recovery was between 100.9% and 101.5%. Conclusion: Three simple fast and accurate spectrophotometric methods for the Carvedilol, Irbesartan, and Timolol Maleate.The results were in good agreement with those obtained by an established UV spectrophotometric method; the methods are practical and valuable for routine application in quality control laboratories.