Discussion and Conclusions
The atomic absorption spectrophotometry method results in the determination of the total stannous (Sn+2 and Sn+4) in the preparations and are usefull to estimate the loss of mass resulted from the lyophilization process. However, the colorimetric spectrophotometric method studied determines only the Sn+2 and allows the evaluation of all critical points of the production process, considering the oxidation of Sn+2 in the preparation.
The spectrophotometric method studied was optimized for the determination of Sn+2 content in citrate-stannous lyophilized preparations. The method was reprodutible considering the different evaluated batches. The method was fast and easy and can be applied to different stages of the production process, in order to guarantee the content of Sn+2 in the preparations.