Gelatin Caps
Executive summary
Gelatin capsules — colloquially “gel caps” or “softgels” — are oral dosage shells made from animal-derived gelatin that have dominated pharmaceutical and supplement packaging for almost two centuries because they are inexpensive, easy to manufacture at scale, and dissolve reliably in the digestive tract [1] [2] [3]. In recent decades plant-based alternatives such as hydroxypropyl methylcellulose (HPMC), pullulan and modified starches have emerged to meet vegetarian, halal/kosher and stability needs, but tradeoffs remain in cost, oxygen permeability and dissolution behavior that shape industry choices [1] [4] [5].
1. What gelatin caps are and how they’re made
Gelatin capsules are shells formed from pharmaceutical-grade gelatin — a protein produced by hydrolyzing collagen from animal skins, bones or connective tissue — and come in two main formats: hard two-piece capsules for powders and softgel (soft) capsules made with added plasticizers for liquids or semi-solids; production methods include dipping molds for hardshells and rotary die filling for softgels [1] [6] [7].
2. Why industry still leans on gelatin: performance and cost
Gelatin remains widely used because it offers low oxygen permeability that protects oxygen‑sensitive active pharmaceutical ingredients (APIs), rapid dissolution in the stomach, and is cheaper to produce than many vegetarian alternatives — manufacturers and trade sources report HPMC capsule raw materials and production costs are multiple times higher than gelatin [4] [1] [8].
3. Stability, formulation limits and technical innovations
Gelatin can be prone to crosslinking under heat, humidity or exposure to certain aldehydes, a reaction that can slow dissolution; suppliers have introduced stabilized gelatins (e.g., RXL® and StabiCaps) and optimized plasticizer blends (glycerol, sorbitol, PEG) to control moisture, mechanical properties and shelf performance of softgels [4] [2] [7].
4. Alternatives and their tradeoffs
Vegetarian capsules — principally HPMC — and other plant polysaccharides like pullulan or modified starch provide non‑animal options that avoid religious or dietary objections, but they can allow higher oxygen penetration (requiring antioxidants or special packaging), often dissolve more slowly in acidic environments, and historically have cost and processing disadvantages compared with gelatin [4] [1] [5].
5. Safety, labeling, and ethical/religious considerations
Gelatin originates from animal sources most commonly bovine or porcine and is therefore not acceptable to some vegetarians, vegans, or adherents of halal/kosher rules unless specifically certified; reputable manufacturers and retailers often label source origins and offer vegetarian or fish‑based alternatives to address these concerns [9] [10] [11].
6. Where manufacturers and advocates diverge — agendas to spot
Industry suppliers emphasize gelatin’s cost-efficiency, scalability and improved stabilized formulations to justify continued market dominance [2] [8], whereas plant‑based capsule advocates and some researchers highlight ethical choices and potential oxygen/dissolution issues with alternatives; regulatory labeling and marketing claims can obscure these tradeoffs, so consumers should watch for certification and explicit sourcing statements [4] [10] [11].
7. Bottom line for formulators and consumers
Choosing gelatin caps remains a pragmatic decision for many drugmakers and supplement brands because of performance, manufacturability and cost, but alternatives are mature enough for many applications — the decision requires balancing oxygen sensitivity of the fill, required dissolution profile, cost constraints and dietary or religious acceptability, and each of those factors is documented in industry and scientific literature [4] [5] [7].