Formulation Strategy and Excipient Selection for Tribulus terrestris L. Tablets: A Quality-Based Approach

Abstract

Background: To develop and evaluate a tablet formulation containing standardized dry extract of Tribulus terrestris L.—a plant traditionally used in Mongolian medicine—by focusing on excipient optimization and pharmaceutical quality assessment. Methods: Tablets were manufactured using the wet granulation method, incorporating an extract standardized to 54.45% dioscin. Various excipient ratios were investigated to determine the optimal formulation. Dioscin content was quantified using UV-visible spectrophotometry. Results: The optimized formulation comprised 25% dry extract, 34% lactose, 34% microcrystalline cellulose, 6% PVPP, 0.5% magnesium stearate, 0.5% talc, and 4.5% HPMC. The tablets demonstrated acceptable pharmaceutical characteristics, including an average weight of 0.113 ± 0.001 g, hardness of 0.83 ± 0.23 MPa, friability of 98.17 ± 0.65%, and disintegration time of 7.30 minutes. The dioscin content was 13.50 ± 0.50 mg/g, with an assay recovery of 95.51%. Dissolution exceeded 83% in both media within 45 minutes. The similarity factor (f₂) confirmed equivalent dissolution profiles. Conclusion: The developed T. terrestris tablet formulation met pharmacopoeial standards and exhibited consistent physical, chemical, and biopharmaceutical performance, supporting its potential as a standardized herbal medicinal product for clinical and commercial application.