Liquid-Filled Capsules vs Softgels: Key Differences, Benefits, Manufacturing Process & How to Choose

Liquid-filled capsules (also called liquid-filled hard capsules or LFHCs) are essentially two-piece hard-shell capsules (gelatin or HPMC) that have been filled with an oil-based or liquid formulation. After filling, the cap and body are sealed – often with a thin gelatin band – to prevent leaks. In other words, LFHCs are a hybrid form: a solid capsule shell containing a liquid dose inside. By contrast, softgel capsules are made in one step as a single, flexible one-piece shell that is already filled with a liquid or semi-solid. Softgels use plasticized gelatin (with glycerin or sorbitol) to make a soft, sealable membrane. They are typically used for very oily or soluble ingredients – for example, fish oil or fat-soluble vitamins (D, E, K) almost always come in softgels.

In practical terms, both formats can deliver liquid drugs or supplements, but their design and production differ significantly. Key differences include capsule structure, shell materials, compatible fills, and manufacturing steps. Understanding these helps pharma manufacturers choose the right form for their product. Below we break down the main distinctions and benefits of each.

What Are Liquid-Filled Capsules?

Liquid-filled hard capsules (LFHCs) are standard two-piece capsule shells (cap and body) filled with a liquid or oil-based formulation after the shells are made. The shells can be made of gelatin or plant-based HPMC (for vegetarian capsules). In production, a precise dose of liquid (often an oil solution, suspension or self-emulsifying mix) is injected into the open capsule body, then the cap is closed on top and sealed. Special sealing methods ensure nothing leaks (for example, applying a thin gelatin band around the joint, called “band sealing”).

This two-piece approach allows LFHCs to combine the benefits of liquids and capsules. You get the quick-release and high bioavailability of a dissolved liquid, with the easy swallowing and masking of taste that capsules offer. LFHC shells are pre-manufactured, so no costly melting of gelatin sheets is needed during fill. For example, JinLuPacking’s NJY-300C liquid capsule filler automatically fills liquids into size #00–#4 hard shells and band-seals them in one fast line.

Figure: Liquid-filled hard capsules (each has a colored band sealing the cap-body joint). These two-piece capsules hold oil or liquid inside a solid gelatin/HPMC shell.

What Are Softgels?

Softgel capsules (often just called softgels) are one-piece, gel-coated capsules containing a liquid or semi-solid fill. They are made on a rotary-die encapsulation machine that forms, fills, and seals each capsule in a single step. In the machine, two ribbons of plasticized gelatin (gelatin mixed with glycerin or sorbitol) are cast and pressed together while a metered stream of liquid is injected between them. Each capsule is simultaneously cut and sealed by heated dies. The result is a smooth, oval, airtight capsule popularly used for oil-based supplements (think vitamin E or omega‑3 pills).

Softgels are ideal for oils and sensitive liquids. Because the entire capsule is hermetically sealed when it’s formed, no separate sealing step is needed. This makes them very protective against oxygen and moisture. Many fish oil, vitamin D/K, and botanical oil products use softgels for their convenience and shelf stability. In fact, surveys show Omega-3 and fat-soluble vitamin supplements are most often delivered as softgels.

Figure: Amber softgel capsules on a teaspoon next to a pill bottle (common for fish oil or vitamin D).

Liquid-Filled Capsules vs Softgels: Key Differences

• Capsule Structure: Liquid-filled hard capsules are two-piece units – a cap and body – that are joined after filling. The cap can in principle be removed (before sealing), making them reopenable in the filling line. Softgels are a one-piece sealed pouch with no separable parts. Once a softgel is formed, it’s hermetically sealed and can’t be opened without breaking the shell.
• Shell Material: Hard capsules are made of gelatin or vegetarian polymer (like HPMC) plus water, without added plasticizers. Softgel shells contain gelatin with plasticizers (e.g. glycerin or sorbitol) to keep them elastic. This means softgel shells are softer and more pliable, whereas hard capsule shells are firmer and dry.
• Fill Types: Standard hard capsules typically hold dry powders, granules, mini-tablets or pellets. In contrast, softgels contain liquid, oil-based, or semi-solid fills. Liquid-filled hard capsules bridge the gap: they use a hard capsule shell but are filled with liquid or suspension, similar to what softgels hold. In practice, softgels handle pure oils and solutions; LFHCs can also accept suspensions or combination fills (e.g. tiny tablets plus oil).
• Manufacturing Process: Hard capsule production is a two-step process. First, empty capsule shells are formed (by dipping molds in gelatin), then later filled and sealed. Softgels are made in a single continuous process on a rotary-die machine: molten gelatin sheets are cast, meet at a filling station where the liquid is injected, and then the capsules are cut and sealed in one motion. In summary:
  • Hard capsules (LFHC): Shells are pre-made; filling and sealing are done later (liquid is pumped into each capsule body, then cap is put on and sealed).
  • Softgels: Shell formation, filling, and sealing happen together on a specialized machine.
• Drying/Curing: Softgels require post-fill drying. The freshly-made softgel shells are moist and need to be tumbled and then tray-dried for hours to reduce moisture to the target level. This curing can take 2–4 days in total. Liquid-filled hard capsules do not need this drying step: once filled and sealed, they can move straight to inspection or packaging.
• Hermetic Seal: Softgels have a continuous hermetic seal by design (the two gelatin layers fuse completely), giving them very low oxygen permeability. LFHCs must use special sealing: typically a thin gelatin band or fusion at the cap-body joint. A band seal provides a strong barrier against leaks, though it is a mechanical patch rather than a continuous shell.
• Production Equipment: Softgel manufacturing requires expensive rotary die encapsulation lines, climate-controlled rooms, and skilled operation. LFHC production can use standard capsule filling machines (with an added liquid pump) which are simpler and often already available in-house. In fact, a typical LFHC line can run a complete batch in a single day, whereas softgels need multi-day gelatin preparation and drying cycles.
• Regulatory/Marketing: Because LFHCs use vegetarian shells (like HPMC) by default, they easily meet vegan/halal standards. Traditional softgels (bovine/porcine gelatin) are not halal/vegan, unless using specialty fish gelatin or non-gelatin alternatives. Softgels are widely recognized in the supplement market (consumers expect fish oil in softgels, for example), while LFHCs look like standard capsules and can be customized in color and printing.

Both forms deliver liquid or oil-based actives and can offer high bioavailability by presenting the drug dissolved in a lipid. However, LFHCs use simpler lines (shells are pre-made) whereas softgels require cooking and drying steps for the gelatin ribbons.

Manufacturing Process Comparison

• Liquid-Filled Capsules: Two-piece shells are pre-fabricated. In the filling line, empty capsules are separated, bodies are filled via metered pumps, then caps are attached and the seam is sealed by banding or fusion. There is no multi-day curing step. Finished capsules go straight to inspection and packaging. This streamlined process (fill one day, seal same day) makes LFHC production very fast.
• Softgels: The process starts with making a gelatin melt: gelatin (plus glycerin/sorbitol and colorant) is mixed into a molten syrup. Two ribbons from this gelatin mass are formed on heated drums. The liquid fill (oil, suspension, etc.) is injected between the ribbons, and the ribbon is cut/sealed into capsules. Crucially, each softgel batch must then dry for 2–4 days before packaging to stabilize its moisture. This drying period adds time and requires controlled humidity rooms. Quality control can only occur after drying (longer lead time).

Key takeaway: Softgel machines form, fill, and cut in one step (necessitating drying), while LFHC lines fill pre-made shells and seal them (skipping a lengthy curing stage). As one industry guide notes, “Softgels cure 2–4 days post-fill. LFHCs have no curing step… batch losses from fill failure are higher for softgels”.

Advantages of Liquid-Filled Capsules

Liquid-filled capsules offer several manufacturing and product advantages:

• Improved Bioavailability for Tough Drugs: LFHCs excel at delivering poorly soluble, low-dose or potent actives. Formulating the API in an oil or lipid solution enhances solubility and absorption compared to a powder. For example, heat-sensitive or waxy compounds can be dissolved in oil and quickly absorbed, often leading to a faster or stronger effect.
• Flexible Development & Dosing: Adjusting dose strengths is easy with liquids. You simply change the concentration of active in the fill. This “quick and simple dose adjustment” makes R&D faster and scale-up smoother. A company can fill the same capsule shell with different concentrations as needed, streamlining clinical and commercial batch changes without new tooling. Prototype batches can even be done in-house with benchtop fillers rather than expensive softgel pilot lines.
• Faster, Lower-Cost Production: Since hard capsule shells are made separately, LFHC production avoids the multi-day gelatin cooking/drying of softgels. An LFHC batch (fill + seal) can be completed in hours or a single day, versus 3–4 days for a softgel line. The equipment is simpler (standard capsule filling machine with a liquid pump). This means lower capital investment, smaller footprint, and higher output per shift. There’s also minimal waste: softgel lines can lose up to ~40% of the gelatin web to trim, whereas LFHCs waste virtually none of the shell material.
• Better Product Stability: LFHC shells (especially HPMC) have lower moisture and oxygen permeability than softgel gelatin shells. HPMC capsules can support very dry fills and block moisture ingress. When combined with hermetic band sealing, LFHC products often have a longer shelf life and are more stable in harsh conditions. In practical terms, the reduced water content and permeability preserve sensitive oils or vitamins better over time.
• Combination Formulations: Because they are two-piece, LFHCs can combine multiple forms in one capsule. You can put a tablet, pellet, or powder along with the liquid fill. For example, a single capsule might hold an oil-based vitamin E liquid and a separate dry tablet of herbal extract. This multi-particulate flexibility is not possible in a one-piece softgel. It lets companies create innovative fixed-dose combos or keep product families with one dosage form.

These advantages make LFHCs attractive in both pharmaceutical and nutraceutical markets.

Advantages of Softgel Capsules

Softgels also have strong benefits that make them popular for many supplements:

• Excellent Oxygen/Moisture Barrier: The hermetic seal of a softgel (the two ribbons are fused) means almost no air or water penetrates. This is ideal for oxygen-sensitive oils (e.g. fish oil, vitamin D) because it prevents oxidation. Many manufacturers trust softgels to keep oils fresh and odor-free for longer.
• High Bioavailability: Like LFHCs, softgels deliver actives in liquid form, which often boosts absorption. The liquid or self-emulsifying fills can provide rapid drug release in the GI tract. Studies show softgels dissolve in ~10–20 minutes, making the active quickly available.
• Ease of Swallowing: Softgels have a smooth, rounded shape and slip down easily with water. This can enhance patient compliance, especially for larger doses. Many people find softgels more pleasant than hard pills.
• Premium Appearance and Customization: Softgel shells can be made opaque, colored, or shaped for branding. For example, tri-color or unique shapes can distinguish a product line. This “cosmetic” advantage adds perceived value on retail shelves.
• Versatile Liquid Fills: Softgels can hold complex formulations – oils, suspensions, or even dissolved powders – without issue. They can encapsulate delicate botanical extracts (e.g. CBD oil, aloe vera) or oil-soluble vitamin blends. The soft, pliable shell also masks unpleasant tastes or odors of the fill.
• Consumer Familiarity: Softgels are an industry-standard for popular supplements (fish oil, vitamin E, prenatal vitamins, etc.), so consumers often expect and accept this format.

Industries using softgels include pharmaceuticals (oil-based medications), nutraceuticals (dietary supplements), cosmetics (nutraceutical beauty oils), and even veterinary products. For instance, vegan or halal softgels made from starch/gellan are on the rise.

Which Ingredients Are Best for Each Capsule Type?

Both capsule types handle oil-soluble actives well. Common nutraceutical oils (fish oil, vitamin D, herbal extracts, CBD, etc.) are effectively delivered by either LFHCs or softgels.

Notably, dry or moisture-sensitive ingredients are better in liquid-filled hard capsules. For example, probiotics or water-sensitive APIs are impractical in softgels. In contrast, HPMC hard capsules can hold non-aqueous suspensions of probiotics or very dry formulations, since HPMC has low moisture and gas permeability. Softgel shells contain about 30% water and higher oxygen permeability, which can degrade such ingredients.

Which Industries Prefer Each Format?

• Liquid-Filled Hard Capsules: Widely used in nutraceuticals and pharmaceuticals, especially for new or small-batch products. Startups or contract manufacturers often favor LFHCs for R&D flexibility and lower initial cost. They’re also used in cosmetics (nutraceutical beauty products) and veterinary supplements where ingredient flexibility is needed.
• Softgels: Favored by large pharmaceutical and supplement companies producing high-volume, established products. Many omega‑3, multivitamin, and prescription oil medications come as softgels due to their consumer recognition and shelf-life. Softgels are also standard for any liquid prescription drug where hermetic sealing is critical.

In short, use LFHCs when flexibility and low-volume production matter; choose softgels for scale and premium shelf appeal.

Which Is Better for Manufacturers?

From a manufacturer’s point of view, the decision often depends on scale, investment, and strategic goals:

• New or Small Producers: Liquid-filled capsule lines have lower startup costs and smaller equipment needs. Because they use standard capsule fillers (with a liquid dosing unit), the same machines can serve existing powder capsule processes with a simple changeover. This keeps capital investment low. Also, LFHCs require smaller minimum orders and shorter lead times, making them ideal for limited runs and fast market entry.
• Large Producers or High-Volume Products: Softgels, though costlier to set up, shine when volumes are huge. High-speed rotary die machines can churn out thousands of softgels per minute once commissioned. For very high-demand items (e.g. top-selling fish oil brands), the per-unit cost of softgels can eventually be lower despite higher overhead. The hermetic sealing also means less risk of manufacturing rejects from leaks.
• Contract Manufacturers: Many CMOs offer both options today. They may steer clients toward LFHCs for early-stage or niche products (due to quick turn-around), and toward softgels for blockbuster formulations that justify dedicated lines.

The table below summarizes the choice by scenario:

Equipment Required

• For Liquid-Filled Capsules: A standard capsule-filling line (either semi or fully automatic) is used, with a liquid filling attachment. Key equipment includes a liquid capsule filling machine (e.g. JinluPacking’s NJY-300C or NJY-1000C) that meters and injects the oil into empty capsules. After filling, a banding machine applies a gelatin (or HPMC) seal around the capsule seam. Finally, dryers and polishers finish the line. JinLuPacking offers dedicated liquid capsule filling machines that integrate pumps, nozzles, and banders on one platform.
  Figure: Close-up of a liquid capsule filling machine dispensing liquid into capsules.
• For Softgels: A complete rotary die softgel encapsulation machine is needed (e.g. JinLuPacking’s softgel line), along with associated units. The softgel line includes a gelatin mixer/pelletizer, gelatin melter, casting drums, rotary die module, and conveyors. After encapsulation, the capsules enter a tumble or drying tunnel (for 24–72 hours) and a polishing/sorting machine. Softgel equipment investment is significant, but it produces finished capsules in one flow.

  

JinLuPacking manufactures a full range of capsule equipment. For example, our NJY-300C liquid capsule filler line handles liquid fills, and we also provide soft gel capsule machines for one-step production. These machines meet cGMP standards for pharmaceutical and nutraceutical use.

Conclusion

In the end, both liquid-filled hard capsules and softgels are well-established, effective dosage forms. Softgels excel at delivering oils and oil-soluble actives with a quick-dissolving, tamper-evident package. Liquid-filled hard capsules offer flexibility, faster R&D scaling, and manufacturing simplicity. By understanding their differences, benefits and production requirements, manufacturers can pick the capsule type that best fits their product’s chemistry and business needs.

If you’re designing a new formulation or upgrading your production line, consider both options carefully. Ready to optimize your capsule production? Jinlu Packing offers industry-leading equipment for both formats (for example, our NJP-1000C can fill up to 60,000 hard capsules per hour) and can advise on the best solution for your product. Contact us to discuss your project, request a quote, or learn more about our liquid capsule and softgel packaging lines.

FAQs on Liquid-Filled Capsules vs Softgels

References：
1.Liquid Filled and Sealed Hard Gelatin Capsules —— Taylor & Francis Online
2.Soft Gelatin Capsules (Softgels) —— ScienceDirect
3.Temperature effects on ribbon characteristics in soft gelatin capsule manufacture —— National Library of Medicine
4.Comprehensive Review on Soft Gelatin Capsules: Industrial Manufacturing, Technological Advancements, and Regulatory Perspectives —— Journal of DRUG DELIVERY & THERAPEUTICS
5.Liquid Filled Hard Gelatin Capsule —— Journal of DRUG DELIVERY & THERAPEUTICS
6.Determination of the optimal amount of water in liquid-fill masses for hard gelatin capsules by means of texture analysis and experimental design —— National Library of Medicine