SIMPLE OF PARA AMINO BENZOIC ACID IN PURE FORM AND PHARMACEUTICAL PREPARATION BY DIAZOTIZATION AND CLOUD POINT EXTRACTION

Abstract

Two simple, sensitive, and economical spectroscopic methods were developed for the quantification of pure para-aminobenzoic acid (PABA) and pharmaceutical preparation. The first method is based on the diazotation reaction of PABA, followed by conjugation with α-naphthol in an alkaline medium to form a stable, water-soluble, dark brown azo dye. The dye formed under optimized experimental conditions exhibited a maximum absorbance of 498 nm. The method showed a wide linear dynamic range of 1.0–12.0 µg/mL, with a correlation coefficient (R² = 0.997). Statistical evaluation of the results demonstrated excellent accuracy and clarity, with a mean recovery of 101.96% and a very low relative standard deviation (RSD) of 0.0083%. The calculated molar absorbance was 10450.0680 L/mol/cm². This was followed by the second photochemical method, which relies on cloud point extraction by using Trtion X-114 as surfactant .The product was measured at 498 nm. The dynamic range was 1.0 to 12.0 µg/mL, with a correlation coefficient (R² = 0.999). Statistical evaluation of the results showed excellent accuracy and clarity, with a mean recovery of 100.24% and a very low relative standard deviation (RSD) of 0.0047%. The calculated molar absorbance was 12219.1740 L/mol/cm². All variables that contribute to improving working conditions in order to obtain better results were studied, namely (type and size of acid, type and size of base, reagent concentration, reaction time and temperature) This also includes studying the) type and size of the active surface, as well as the effect of temperature and product stability time) within the cloud point extraction technique. Thanks to its simplicity and high accuracy, the developed method is very suitable for routine quality control and pharmaceutical analysis of para-aminobenzoic acid (PABA). It should be noted that both methods were applied successfully and no interference was observed from any additive used in the working method, and it did not affect the results at all.