Ion-pair complex

A simple, rapid, sensitive, accurate, precise spectrophotometric method has been developed for the estimation of Tamsulosin in the presence of Dutasteride  in pharmaceutical formulations. During the course of study, it is observed that acidic solution of the drug formed colored ion-association complexes with Bromo Thymol Blue (BTB) which is soluble in methanol. This property of the drug was followed for the development of spectrophotometric method for analysis of drug. The complex of Tamsulosin in the presence of Dutasteride with Bromo Thymol Blue showed ?max at 430 nm. The linearity range for Tamsulosin in the presence of Dutasteride was 10 µg/ml to 250 µg/ml. Recovery studies gave satisfactory results indicating that none of common additives and excipients interfere the assay method. The molar absorptivity and the sandell sensitivity of the method are found to be 6.6123×104 lit/mole/cm and 0.0067 µg/ml/cm2 respectively.