STUDY OF MUTUAL INFLUENCE OF SALICYLIC ACID AND RESORCINOL ON THEIR STABILITY IN THEIR JOINT PRESENCE IN ALCOHOL SOLUTION

Aim. Study of mutual influence of salicylic acid and resorcinol on their chemical stability in the joint presence in alcoholic solution, determination of period of validity of this drug. Materials and Methods. Study object: alcoholic solution containing resorcinol and salicylic acid. Control of stability was based on evaluation of organoleptic properties and changes in the quantity of resorcinol and salicylic acid during storage. The quantity of resorcinol was determined by the method of reverse bromatometry; the quantity of salicylic acid – by alkalimetry. Statistical analysis of the results was performed in accordance with the requirements of General Monograph of Russian State Pharmacopoeia, 13th edition. Results. Organoleptic control showed a change in the color of the solution by the 30th day of storage. The quantitative content of resorcinol gradually decreased after the 20th day due to oxidative processes, and went beyond the control limits by the 30th day of storage. The quantitative content of salicylic acid in the solution increased after 20 days of storage due to oxidative processes associated with formation of acidic products, and by the 30th day went beyond the control limits in two of six studied samples. A study of the influence of package showed that in flasks made of colorless packing medical glass (MTO grade) stability of the studied solution considerably decreased. The quantitative contents of resorcinol and salicylic acid went beyond the permissible limits by the 20th day of storage. Conclusions. It was observed that the content of salicylic acid and resorcinol in alcoholic solution kept within the normal limits within 25 days of storage, and this allows to recommend 20-day period of validity of this solution. The solution should be dispensed from pharmacies only in flasks made of dimming glass.