17/08/2026
What Causes Softgel Capsules to Lose Their Ideal Hardness?
Too hard? Too soft? Or inconsistent hardness within the same batch?
For softgel manufacturers, abnormal capsule hardness can be more than a minor quality issue.
It may lead to:
❌ Capsule deformation
❌ Sticking during production or packaging
❌ Brittleness or cracking
❌ Leakage risks
❌ Inconsistent product quality
❌ Problems during storage and transportation
But what causes softgel capsules to become too hard or too soft?
The answer usually isn't just one parameter.
Let's break it down. 👇
🔍 Why Does Softgel Hardness Matter?
The hardness and elasticity of a softgel shell directly affect its mechanical properties and overall quality.
A capsule that is too soft may deform easily, stick to other capsules, or become difficult to handle.
A capsule that is too hard may lose elasticity and become more susceptible to cracking or brittleness under certain conditions.
So the goal isn't simply to make softgels harder or softer.
👉 The goal is consistent and appropriate shell properties for the specific formulation and production process.
5 Key Factors That Can Affect Softgel Hardness
1️⃣ Shell Formulation
The shell formulation is one of the most important factors.
Key variables include:
• Gelatin type and concentration
• Plasticizer content
• Water content
• Raw material quality
• Other formulation components
The balance between gelatin, plasticizer, and moisture has a major influence on shell flexibility and hardness.
For example, excessive moisture loss may contribute to a harder, less flexible shell, while excessive plasticizer or residual moisture may contribute to a softer shell.
👉 The key is balance—not simply increasing or decreasing one ingredient.
2️⃣ Gel Mass Preparation
Before encapsulation, the gel mass needs to be properly prepared.
Important factors include:
🌡️ Heating temperature
🔄 Mixing time and efficiency
💨 Vacuum deaeration
⚖️ Gel mass homogeneity
💧 Moisture distribution
Poor mixing may result in inconsistent gel properties.
Insufficient deaeration can introduce air bubbles and affect ribbon quality.
That's why:
Consistent softgel quality starts with consistent gel mass preparation.
3️⃣ Encapsulation Parameters
Even when the shell formulation is correct, improper machine settings can create quality variations.
Pay attention to:
• Gel ribbon thickness
• Wedge temperature
• Die roll temperature
• Encapsulation speed
• Fill weight
• Sealing conditions
For example, inconsistent ribbon thickness can affect the shell characteristics of the finished capsule.
Improper sealing conditions may also affect capsule integrity.
👉 Softgel encapsulation is not simply a filling process. It is a precisely controlled process involving multiple interacting parameters.
4️⃣ Drying Conditions
This is one of the most critical stages.
And here's an important point:
Drying isn't simply about removing water.
The objective is to achieve the right final moisture balance and shell properties.
Important factors include:
🌡️ Drying temperature
💧 Relative humidity
⏱️ Drying time
💨 Airflow
📦 Capsule loading density
🔄 Tumble drying conditions
Insufficient drying may leave capsules too soft or increase the risk of sticking.
Excessive or overly aggressive drying may remove too much moisture and contribute to hardening or brittleness.
👉 The real goal is controlled and uniform moisture removal.
5️⃣ Storage & Environmental Conditions
Did you know that softgel hardness can continue to change after production?
Temperature and humidity can affect moisture migration and the mechanical properties of the shell.
Consider:
🌡️ Storage temperature
💧 Relative humidity
📦 Packaging conditions
⏳ Storage duration
🛡️ Packaging barrier properties
For example, high humidity may contribute to moisture uptake, softening, or sticking.
Very dry conditions may contribute to moisture loss, hardening, or brittleness.
That's why:
A capsule that looks perfect immediately after production may behave differently after storage.
🛠️ How to Troubleshoot Abnormal Hardness?
Don't change production parameters randomly.
Instead, identify where the problem first appears.
If capsules are TOO HARD:
Check:
✔️ Shell moisture
✔️ Plasticizer level
✔️ Gelatin formulation
✔️ Drying conditions
✔️ Storage humidity
✔️ Excessive moisture loss
If capsules are TOO SOFT:
Check:
✔️ Residual moisture
✔️ Plasticizer level
✔️ Gelatin concentration
✔️ Drying adequacy
✔️ Environmental humidity
If hardness varies within the SAME BATCH:
Pay special attention to:
✔️ Gel mass homogeneity
✔️ Ribbon thickness
✔️ Encapsulation parameters
✔️ Drying airflow distribution
✔️ Capsule loading density
✔️ Temperature and humidity variations
If capsules become HARDER during storage:
Investigate:
✔️ Moisture migration
✔️ Packaging performance
✔️ Storage humidity
✔️ Storage temperature
If capsules become SOFT or STICKY during storage:
Check:
✔️ Environmental humidity
✔️ Residual moisture
✔️ Packaging barrier properties
✔️ Storage temperature
✔️ Drying conditions
💡 How Can Manufacturers Prevent These Problems?
The best troubleshooting strategy is prevention.
A stable softgel production process should focus on several areas:
① Standardize Raw Materials
Maintain consistent specifications for gelatin, plasticizers, and other shell materials.
② Control Gel Mass Preparation
Keep heating, mixing, deaeration, and moisture conditions stable.
③ Monitor Critical Encapsulation Parameters
Control ribbon thickness, temperature, filling, sealing, and machine speed.
④ Optimize the Drying Environment
Don't focus only on temperature.
Consider the complete drying environment:
Temperature + Relative Humidity + Airflow + Drying Time + Loading Conditions
⑤ Monitor Quality During Storage
Don't evaluate the capsule only immediately after production.
Where appropriate, monitor hardness, moisture, appearance, and integrity during storage and stability studies.
⚙️ What About the Equipment?
Formulation is important—but equipment stability also matters.
A reliable softgel encapsulation system should provide stable control of critical parameters such as:
✔️ Gel ribbon thickness
✔️ Gel and wedge temperatures
✔️ Filling accuracy
✔️ Encapsulation speed
✔️ Die roll synchronization
✔️ Sealing conditions
Stable equipment performance can help reduce process variation and improve batch-to-batch consistency.
For softgel manufacturers, the question isn't only:
"How fast can the machine run?"
It's also:
"Can the machine maintain stable and repeatable process conditions throughout the production run?"
🎯 Final Takeaway
Abnormal softgel hardness is rarely caused by a single factor.
It can be the result of interactions between:
Formulation → Gel Mass Preparation → Encapsulation → Drying → Storage
A systematic troubleshooting approach can help manufacturers identify the root cause instead of simply adjusting parameters repeatedly.
👉 Consistent softgel hardness comes from controlling the entire process—not from adjusting a single parameter.
What softgel quality problem do you encounter most often—hardness variation, sticking, deformation, or leakage?
Share your experience in the comments. 👇
