Formulation and Evaluation of Quality Parameters of Effervescent Granules from the Potent Antioxidant between Two Variants of the Adaptogenic Herb Ocimum tenuiflorum L.

Ocimum tenuiflorum L. is found throughout semitropical and tropical parts of Southeast Asia. In Nepal, O. tenuiflorum L. is popular with two variants: Krishna Tulsi consisting of purple-colored leaves and Sri Tulsi consisting of green-colored leaves. O. tenuiflorum L. is considered the queen of herbs and is a traditionally and clinically proven medicinal herb for its application and efficacy. However, no commercial pharmaceutical preparations of O. tenuiflorum L. are available using effervescent vehicles. Therefore, the present study aimed to compare the antioxidant activity of leaves from the two varieties of O. tenuiflorum L. and formulate and evaluate the quality parameters of effervescent granules of the potent extract. The antioxidant activity of O. tenuiflorum L. ethanolic extracts was evaluated by DPPH radical scavenging assay at 1, 10, and 100 µg/mL concentrations, where ascorbic acid was used as the positive control. The antioxidant activity of purple-leafed O. tenuiflorum L. was found to be higher than that of green-leafed O. tenuiflorum L. Therefore, effervescent granules of the ethanolic extract of purple-leafed O. tenuiflorum L. were formulated using the pharmaceutical excipients tartaric acid, citric acid, and sodium bicarbonate and the quality parameters of the granules were evaluated. The formulated granules met the quality parameters assessed from the angle of repose, bulk density, tapped density, Carr's Index, Hausner's ratio, effervescent cessation time, and stability studies. Thus, the formulated effervescent granules of O. tenuiflorum L. can be used for therapeutic purposes or as a functional food.