Do single‐ and multi‐ingredient botanical dietary supplements containing green tea pass the United States Pharmacopeia's (USP) disintegration and dissolution requirements?
Authors: Gusev Pavel A , Andrews Karen W , Savarala Sushma , Dang Phuong‐Tan V , Oh Laura Y , Pehrsson Pamela R , Dwyer Johanna T , Betz Joseph M , Costello Rebecca B , Saldanha Leila G , Kuszak Adam J 
Published: November 2023

The bioactivity of dietary supplements (DSs) is determined by the active ingredient (AI), amount of AI and by the design and performance of the dosage form into which the AI is incorporated. As a part of the Botanical Initiative for the Dietary Supplement Ingredient Database (DSID; http://dsid.usda.nih.gov), DSs containing green tea (GT) extract and/or GT leaf as primary ingredients (GT‐1 DSs) or in combination with other ingredients (GT‐2 DSs) were tested using USP disintegration and dissolution protocols (chapter <2040>). These tests detect problems with ingredient release that may arise due to coatings, lubricants, disintegrants, lot to lot over drying, and over compression. These tests are not intended to directly predict DS performance in the gastrointestinal tract or bioavailability. We evaluated whether single‐ and multi‐ingredient GT DSs met USP specifications for disintegration and dissolution.

Six units of each DS were individually immersed and agitated in designated solutions. A formulation passed a disintegration test if, after ½ hour, remaining material had fragments of coating or capsule shell but not a palpably firm core. Dissolution tests measured the amount of epigallocatechin gallate (EGCG) in the agitation medium. A formulation passed this test if, after 1 hour, ≥ 75% of the EGCG amount was accounted for in the solution.

The overall disintegration pass rate in GT‐1 lots 1–3 was 56.7% (47 out of 83 tests). Of 29 products tested in 2 lots, 16 passed and 12 failed in both lots. Of 22 products tested in 3 lots (3rd lot purchased one year later), 8 products passed and 7 failed in all 3 lots. The overall pass rate in GT‐2 lots was 65.4% (51/78). Of 36 GT‐2 products, 21 passed and 10 products failed in both lots. Results for the remaining DSs were inconsistent. Most caplets and tablets in GT‐2 DSs failed to disintegrate. For gelatin capsules and soft gels, the pass rates were high in both GT‐1 (25/32) and GT‐2 DSs (12/13). For non‐gelatin capsules (mostly cellulose‐based), the pass rate was high in GT‐2 (24/31) but low in GT‐1 DSs (21/47). Importantly, we observed consistent disintegration results across duplicate samples.

All 24 GT‐1 DSs from lot 3 failed the dissolution tests under the three conditions (pH 1.2; 4.8 or 6.4, with no enzymes added to the media, 75 paddle RPM). Products that passed the disintegration tests showed somewhat higher mean dissolution rates than those that failed (pH 1.2: 35.7 ± 20.7 vs. 3.4 ± 4.68, % EGCG dissolved, mean ± SD). We explored the effect of an additional 1 hr. of agitation, but this only marginally increased the mean percent dissolved EGCG. Gelatin hard shell capsules tended to release more EGCG than non‐gelatin vegetarian capsules (pH 1.2: 42.5 ± 17.2 vs. 8.3 ± 13.9).

Thus, none of the GT DSs passed USP dissolution test and many failed to disintegrate. The consistent disintegration results across the duplicate samples demonstrate its utility for evaluating this aspect of GT DS quality control across the product lots.

Support or Funding Information

ARS/USDA & ODS/NIH Y1CN501006