Formulation and development of capsules containing dry extracts from the calyces of Hibiscus sabdariffa L. and the sheaths of Sorghum caudatum H., intended as a dietary supplement

---

Résumé

Introduction: Anthocyanin-rich extracts from Hibiscus sabdariffa L. calyces and Sorghum caudatum H. sheaths are promising antioxidants, but instability and dose variability limit use. This study aimed to standardize and manufacturing capsules containing lyophilized and purified dry extracts with affordable, plant-based excipients.
Methodology: An experimental program (Ouagadougou, Nov 2022–Aug 2023) prepared three extracts, lyophilized H. sabdariffa, purified H. sabdariffa, and purified S. caudatum. Physicochemical and pharmacotechnical tests assessed appearance, pH, hygroscopicity, residual moisture, and powder flow (angle of repose, Carr index, Hausner ratio). Total anthocyanins were quantified by differential pH (H. sabdariffa) and Stonestreet (S. caudatum). Size-0 capsules were formulated with maize starch and, when needed, colloidal silica; quality control evaluated appearance, mass uniformity (n=20), and disintegration (n=6).
Results: Extracts were acidic (pH 4.4–5.3), had residual moisture <10%, and were hygroscopic. Anthocyanins were 11.33±0.49 mg/g (lyophilized H. sabdariffa), 83.91±0.15 mg/g (purified H. sabdariffa), and 317.77±10.07 mg/g (purified S. caudatum). Flow was fairly good for lyophilized Hibiscus (Hausner 1.25) but poor to extremely poor for purified extracts (1.39–1.64); colloidal silica improved filling. Capsules were cylindrical, smooth, and compliant for mass uniformity; mean disintegration was 2.88–3.91 min.
Discussion: Capsules manufacturing enhanced standardized dose delivery, masked acidity, and limited environmental degradation. Gaps include granulometry, microbiological testing, post-formulation flow testing, and finished-product anthocyanin assay; ICH-aligned stability, dissolution in biorelevant media, and content uniformity are recommended.
Conclusion: Bench-scale standardization and capsules manufacturing yielded reproducible, rapidly disintegrating caps

Mots-clés

Hibiscus sabdariffa L., Sorghum caudatum H, anthocyanins, capsules