Linagliptin is an oral antidiabetic agent, used to treat type 2 diabetes. It is taken orally independently or in combination with Empagliflozin and Metformin HCl. Chromatographic Analysis methods were demonstrated for simultaneous analysis of two or three antidiabetic drugs (Linagliptin, Empagliflozin and/or Metformin). This article is interested in the validation of a simple, fast and specific method that relies on chemical derivatization and uses a VIS spectrophotometer to determine LINA in pure and combination drug products alongside Empagliflozin and Metformin. The developed method was reached by reacting LNG with Para-Dimethylaminobenzaldehyde (PDAB) 5% in an acidic medium (Hydrochloride 37%) in a water bath to produce a yellow Schiff base which can be measured at a wavelength of 407 nm. The developed method has good accuracy and precision. PDAB does not interact with Empagliflozin or Metformin under these optimal conditions. Therefore, this developed method is distinguished by its accuracy and specificity in assaying Linagliptin both alone and in combination drug products.

A simple, economical, and specific analytical method has been developed for determining and validating linagliptin (LNG) in bulk. This method is based on a condensation reaction between a primary amine in LNG and an aldehyde group in P-dimethylaminobenzaldehyde (PDAB) to form the yellow Schiff base with a wavelength of 407 nm. The optimum experimental conditions for the formulation of the colored complex have been studied. The optimum conditions were 1 mL of 5% w/v reagent solution with methanol and distilled water as a solvent for both PDAB, LNG respectively, also adding 2 mL of HCl as an acidic medium, heating to 70–75 °C on a water bath for 35 min. Furthermore, the stoichiometry of the reaction has been studied according to Job’s and Molar ratio method which was expressing 1:1 for LNG and PDAB. The researcher modified the method. The results show that the linearity in the concentration range (5–45 µg/mL) with correlation coefficient R2 = 0.9989 with percent recovery (99.46–100.8%) and RSD was less than 2%, LOD and LOQ 1.5815 − 4.7924 μg/mL respectively. This method can show high quality and there is no significant interference with excipients and in pharmaceutical forms. None of the studies showed the development of this method before.

A simple, economical and specific analytical method have been developed for determining and validation Linagliptin (LNG) in bulk. This method is based on condensation reaction between a primary amine in LNG and aldehyde group in P-Dimethylaminobenzaldehyde (PDAB) to form the yellow Schiff base with a wavelength at 407 nm. The optimum experimental conditions for the formulation of the colored complex have been studied. The optimum conditions were 1 ml of 5% w/v reagent solution with methanol and distilled water as a solvent for both PDAB, LNG respectively, also adding 2 ml of HCl as an acidic medium, heating to 70 - 75℃ on a water bath for 35 minutes. Furthermore, the stoichiometry of reaction has been studied according to Job’s and Molar ratio method which was expressing 1:1 for LNG and PDAB. The researcher modified the method. The results show that the linearity in the concentration range (5-45 µg/ml) with correlation coefficient R² = 0.9989 with percent recovery (99.46 – 100.8%) and RSD was less than 2%, LOD and LOQ 1.5815 -4.7924 μg/ml respectively. This method can show a high quality and there is no significant interference with excipients and in pharmaceutical forms. None of the studies showed a developing of this method before.