Development of a New Spectrophotometric Visible (VIS) Analysis Method of Loratadine in Pharmaceutical Tablets

Loratadine is an effective antihistamine, or anti-H1 histamine receptor inhibitor, frequently used to relieve the major symptoms of hay fever and hives of the skin. It is a tricyclic H1 inverse agonist that is used to treat various allergies, like allergic rhinitis, nasal congestion and chronic idiopathic urticaria. The main purpose of this research was to find and develop a new spectrophotometric method in the visible (VIS) range for the quantitative analysis of Loratadine from various samples, including pharmaceuticals, and to exactly compare the final experimental obtained result with the officially stated amount of Loratadine reported on the tablet. Following the quantitative color reaction with alpha naphthylamine 0.2% from an alkalized alcoholic solution, in the presence of sodium nitrite 4-5% and hydrochloric acid 10-15% solution, an intense bright orange azo dye with a reddish shade quantitatively obtained was analyzed at its maximum absorption wavelength λ = 490 nm. The amount of pure Loratadine in the pharmaceutical was found to be 9,777 mg of pure active substance / film-coated tablet, very close to the official stated reference value of 10 mg, corresponding to 97.776 % of pure Loratadine. The average percentage deviation was (+) 2.224 %, below the maximum allowed average percentage deviation (± 7.5 %) imposed by the rules of the Romanian, European and International Pharmacopoeias. The proposed method was linear over the entire standard concentration range of 0,75 µg/mL- 11.25 µg/mL. The linear regression coefficient (R² = 0.9993, R2 ≥ 0.9990) and the correlation coefficient (R = 0.9996, R > 0.9990) were within the normal range of values. The standard error of the regression line was very low, within the normal limits: SE = 0.007078, SE <<1 . The applied method was subjected to a complete statistical validation process. All statistical parameters were found to be within the normal accepted values.