Humidity Control for Gelatin Capsule Filling Rooms: The Key to Preventing Deformation and Sticking

Humidity Control for Gelatin Capsule Filling Rooms: The Key to Preventing Deformation and Sticking

In the pharmaceutical industry, hard capsules (containing powder/granules) and soft capsules (Softgels - containing liquids like fish oil or vitamins) are the most popular dosage forms due to their convenience. The core component of this protective shell is Gelatin (extracted from collagen). However, gelatin is naturally highly "hygroscopic" (water-attracting). Controlling the environment in the capsule filling room is considered by engineers to be the most rigorous balancing act—because "too dry destroys it, and too humid ruins it."

1. Decoding the Pain: Why is Gelatin "Mushy when Humid, Brittle when Dry"?

Unlike effervescent tablets which only fear high humidity, Gelatin capsule shells require absolute balance to maintain their physical-mechanical properties (elasticity and compressive strength):

• When Humidity > 40% (Too Humid): Gelatin rapidly absorbs water from the air. The shell becomes mushy and sticky. Consequently, capsules stick together in the hopper, jam the rotary press molds, or stick to the aluminum foil during blister packaging, distorting the standard capsule shape of the medication.
• When Humidity < 30% (Too Dry): Water within the gelatin structure evaporates back into the environment, causing the shell membrane to shrink and completely lose its elastic toughness. The capsules become brittle and are highly prone to cracking during blister pressing or transportation vibration. This causes active ingredient leakage—a particularly severe disaster for softgels containing liquid fish oil or vitamins.

2. Specialized Humidity Standards for Gelatin Lines

According to Pharmacopeia recommendations and GMP experts, capsule production lines must strictly adhere to the following parameter ranges:

3. Why are standard HVAC systems powerless?

To maintain 35% humidity in a 20°C environment, the dew point temperature must be dropped significantly low. If a chiller/VRV system is used to force condensation, the cooling coil surface will freeze solid, halting operation. If this is mitigated by using electrical resistance to heat the air and reduce relative humidity, the heat will melt the gelatin shells. The intervention of specialized desiccant rotor technology is absolutely mandatory!

4. 2 DeAir Solutions: Meeting all infrastructure and budget needs

Understanding that every pharmaceutical plant has different infrastructure conditions and budgets (between retrofitting old workshops and building new plants), DeAir engineers provide 2 customizable options:

Option 1: Stand-alone Rotor Dehumidifier

A separate unit that operates by circulating air on-site, drawing room air through a Silica Gel rotor wheel for deep moisture extraction, and blowing 35% dry air back into the production room.

✅ Pros:

• Low Investment Cost: Ideal for small encapsulation rooms or limited retrofitting budgets.
• Simple Maintenance: Easy to dismantle, clean filters, and service.

❌ Cons:

• Uneven humidity distribution compared to a central system (especially in large or partitioned rooms).
• Lacks fresh air supply and deep filtration integration.

👉 Detailed reference: Dezenno Stand-alone Rotor Dehumidifiers

Compact standalone rotor units, easily installed directly in the production room.

Option 2: Centralized AHU with Integrated Rotor

An "All-in-one" central air handling system integrating Cooling + HEPA Filtration + Deep Desiccant Rotor, distributing conditioned air via insulated ductwork.

✅ Pros:

• Absolute PID Control: Steadfastly maintains standard 35% humidity in every corner of the space.
• GMP Cleanroom Standards: Integrated HEPA (H13/H14) filters provide sterile fresh air meeting Class C/D standards.
• Space Saving: The unit is placed on the roof or in a mechanical room, completely freeing up space in the capsule filling room.

❌ Cons:

• Higher initial investment cost.
• Requires synchronized ductwork design and installation with the plant's infrastructure.

👉 Detailed reference: Customizable AHU Dezenno.MAX Solutions

Premium Dezenno.MAX AHU combinations, 100% manufactured in Vietnam.

Real-world video of the specialized Dezenno Rotor Dehumidifier system for pharmaceutical plants:

5. Frequently Asked Questions (FAQ)

Medical & Pharmacopeia References:
[1] ISPE (International Society for Pharmaceutical Engineering) - HVAC Design Guidelines for Pharmaceutical Facilities.
[2] USP (United States Pharmacopeia) - Analysis of physical-mechanical properties of hard Gelatin capsule shells and Softgels under the influence of relative humidity.