The global pharmaceutical excipient industry has witnessed a transformative innovation in 2025: one-step enteric hollow capsule technology. By leveraging a proprietary blend of composite starch and seaweed-specific gum, this breakthrough eliminates the need for secondary enteric coating-an age-old bottleneck in traditional manufacturing-while delivering superior gastrointestinal targeting. This innovation not only streamlines production but also addresses critical limitations of conventional enteric capsules, such as coating unevenness and delayed release consistency.
Material Synergy Enables One-Step Formation
At the core of this innovation lies the tailored design of raw materials and process integration:
Proprietary Material Blend: The capsule shell is formulated using a dual-component matrix: (1) modified composite starch (derived from non-GMO potato and cassava, with a degree of substitution optimized to 0.3–0.5) and (2) purified seaweed-specific gum (extracted from Laminaria japonica, rich in alginic acid and fucoidan). This blend undergoes thermal gelation during dip-coating, naturally forming a cross-linked barrier layer that exhibits pH-dependent solubility-an inherent enteric property .
Integrated Dip-Coating Process: Unlike traditional methods where enteric functionality is added post-shell formation, this technology embeds enteric performance directly during the initial preform creation. As the mold pins are dipped into the composite material slurry (maintained at 42±2℃ with a viscosity of 350–400 cP), the starch-gum matrix polymerizes uniformly around the pins. A controlled pre-drying stage (28℃, 45% RH for 15 minutes) further stabilizes the cross-linked structure, ensuring the shell retains enteric properties without additional coating .
Key Advantage Over Traditional Coating: Secondary enteric coating (typically using methacrylic acid copolymers) often suffers from uneven film thickness (variation ≥15%) and risk of coating detachment. The one-step process achieves thickness uniformity of ±5% and eliminates inter-layer adhesion issues, as the enteric barrier is part of the capsule shell itself .
Peptide & Protein Drugs: Peptides (e.g., insulin, glucagon-like peptide-1 analogs) are susceptible to degradation by gastric proteases. The one-step enteric shell forms a physical barrier against proteases while avoiding the risk of peptide adsorption to secondary coating layers- a common issue with traditional capsules that reduces bioavailability by 10–15%. Clinical trials with a peptide-based anti-diabetic drug showed a 22% higher bioavailability when delivered via one-step enteric capsules versus traditional counterparts .
Traditional Chinese Medicine (TCM) Extracts: Many TCM extracts (e.g., berberine, ginsenosides) cause gastric irritation or are unstable in acid. The one-step technology enables targeted release in the small intestine, reducing adverse gastrointestinal effects by 60% while preserving the efficacy of heat-sensitive components (lost in traditional secondary drying) .