Solubility and Thermodynamic Analysis of Antihypertensive Agent Nitrendipine in Different Pure Solvents at the Temperature Range of 298.15 to 318.15°K.

The aim of the present study was to ascertain the solubility of nitrendipine (NP), an antihypertensive drug in six different pure solvents such as water, ethyl acetate (EA), ethanol, isopropyl alcohol (IPA), polyethylene glycol-400 (PEG-400), and Transcutol at temperature from 298.15 to 318.15 K under atmospheric pressure (p) of 0.1 MPa. Experimental solubility data of NP was fitted with Apelblat and ideal models. The mole fraction solubility of NP was found maximum in PEG-400 (6.85 × 10-2 at 318.15 K) followed by Transcutol (4.65 × 10-2 at 318.15 K), EA (1.68 × 10-2 at 318.15 K), ethanol (2.83 × 10-3 at 318.15 K), IPA (2.69 × 10-3 at 318.15 K), and water (1.29 × 10-7 at 318.15 K). The dissolution activity of NP was observed as an endothermic, spontaneous, and an entropy-driven in most of studied pure solvents. The solubility data of NP obtained in the present study could be useful in purification, recrystallization, and dosage forms design of NP.