SUMMARY
The work is devoted to development of the method for quantitative determination of phenylephrine hydrochloride in the combined nasal drops Gripocitron Rinis. Combination of phenylephrine hydrochloride possessing the vasoconstrictor action with dimetindene maleate having the antihistaminic action formulated into drops decreases nasal discharge and helps to clear the nasal passages without disturbing physiological functions of the ciliated epithelium and mucous membrane. It has been found that the quantitative content of phenylephrine hydrochloride in the combined nasal drops can be determined by spectrophotometry in the ultraviolet spectrum at the wavelength of 296 nm. The method proposed demonstrates the possibility of phenylephrine hydrochloride determination in combined drops in the presence of another active pharmaceutical ingredient – dimetindene maleate, which has the absorption minimum in sodium hydroxide solution at this wavelength. The influence of the additional ingredient – benzalkonium chloride drops on the nature of the absorption spectrum of phenylephrine hydrochloride is recommended to eliminate by the action of potassium dichromate solution. The optimal amount and concentration of solutions of sodium hydroxide and potassium dichromate, the analytical band have been determined. Validation of the given method has been carried out according to the following validation characteristics: linearity (a = 4.34 = maxa 5.10%, b = 1.04), accuracy (0.52 = maxd 1.02%), convergence (1.07% = max ?as 3.20%) and the correlation coefficient r, which is 0.9997. It has been found that the method suggested for determination of phenylephrine hydrochloride in nasal drops is precise, accurate, reproducible and linear, and it allows recommending it for using in pharmaceutical analysis.