The aim of this research was to exactly quantify pure sodium metamizole from tablets , using a brand new and developed spectrophotometric analysis method in Visible range (VIS). Main objectives consisted in comparing Sodium Metamizole found content with the stated amount of pure active substance declared by pharmaceutical company, according to the official rules of Romanian, European and International Pharmacopoeias. The method applied has been subjected to a validation protocal which consisted in the analysis of the following parameters: linearity of the method, detection limit (LD) , quantitation limit (LQ), Sandel’s sensitivity, interference of excipients, stability of prepared solutions, method and system precision, accuracy of the proposed method. Following actual dosing, pure sodium metamizole amount in tablet of pharmaceutical was found to be 477.477 mg assigned to a percentage content of 95.495 %, very close to official declared amount (500 mg), with an maximum average percentage deviation of only 4.505 % from the official declared active substance content. This value was situated below the maximum admissible percentage deviation from stated active substance content (± 5%), established by European and International Pharmacopoeias and also by Romanian Pharmacopoeia, X-th Edition rules.
Key words: sodium metamizole, analgesic action, validation protocol, detection limit, quantitation limit, interference of excipients, stated amount, official rules, Sandel’s sensitivity.