What is Blister Pack?
Blister packaging involves forming a heat softened plastic film into a deep drawn pocket moulds to form a tray (thermoforming), filling with a solid dosage form product and sealing with a push through or peel able covering.
Appropriate heat and pressure must be applied to ensure that permanent sealing will be formed which will protect the product from external environment throughout its self-life.
Why Blister packaging?
- Product integrity
- Product protection
- Tamper evidence
- Reduced possibility of accidental misuse
- Patient compliance.
- Better than bottle
Classification of Blister Packing Machines
- Flat forming and Flat sealing type machines
- Flat forming and Rotary sealing type machine
- Rotary forming and Rotary sealing type machines
Flat forming and Flat sealing type Machines
- PAMPAC BQS
- PAMPAC BP 602
- PAMPACK BP 302
- PAMPAC MINIBLIS
- PG Express
- PG TR102/TR 100
- ELMACH 3020
- CAM NMX
Flat forming and Rotary sealing type Machines
- ELMACH 3000
- PG 230/ 230T/ 230XT
- PAPID PACK 230
- ROMACO NOCK 912
- HOONGA, HM 400
Rotary forming and Rotary sealing type Machines
- PG PHARMAPACK 240 CH
- PG ROTOVAC 210V
- PG ROTOVAC 210S
- ELMACH 2300
- ELMACH 2500
Change Parts in Blister machine
| Change Part Name | Use / Importance | Important to remember |
| Feeding Drum | To feed product (Tablet / Capsules) in the Web | Link between Chute and Web hence alignment with both is important |
| Indexing Roller | To Pull the web for cutting in punching station | Improper alignment between cavities can lead to denting. |
| Embossing Holder and hammer | To over code the details on blister | Letters alignment (Reverse and Forward types) |
| Guide Piece | To guide the web (2 No’s) | Attached after forming and before sealing station |
| L- Type Brackets | To fix the Feeding Chute | Height adjustment is important |
| Printing drum | To over code the details | Location of stereos is important |
| Guide Plate / Track | To Guide the Web | Fixed Position |
| Feeding Sector | Product alignment and feed towards chute | Fixed position |
| Feeding Chute and Spring | To Feed the product from vibrator to Web (Rotary) | Alignment with drum (Alu/Alu) and Web (PVC). Height adjustment, Pocket Centering depends on product type. |
| Upper / Lower Forming Plate | To Form Cavities – Air Blow for Hot Forming and Plug Assist for Alu/Alu | Fixed Positions. Pressure and temperature requirements are as per change parts. |
| Upper / Lower Sealing plate | To Seal the web | Alignment of cavities with forming web. OR leads to damaged pockets |
| Main CAM | Draw Off length of the web is decided by this CAM | Complete setup of machine depends on this. |
| Punching Tool | To Cut the Blister from the web | Fixed positions |
| Perforation Tool | To Form deep cuts in the web to separate each unit | Fixed positions |
| Cooling Plate | To Cool the web after sealing | Water temperature needs monitoring. 10 to 12 0C for Alu/Alu 8 to 10 0C for PVC/Alu |
Critical Parameters in Packing
Forming Temperature:
a) Determines the quality of pockets getting formed.
b) It is based on packing material type and dimension of unit.
Sealing Temperature
a) It determines the leak test results
b) It is a combination of pressure, plate knurling also.
Speed of machine
a) It differs from machine to machine and depends on
b) And based on type of Packing materials used.
Pressure:
a) It is applicable for cold forming and sealing of blisters and affects on the quality of product.
Leak Test:
Why is it done?
Performed to assess the possibilities of leaks in the blister.
Frequency
Done at 2 hours interval, during start up and shut down and batch completion
No. of blisters to be taken
10 blisters in case if one stroke yields less than 10 blisters or
All blisters in case if one stroke yields more than 10 blisters.
Method
2-3 drops of methylene blue shall be used as color indicator.
Water level should be 3 liters approx.
Hold under vacuum for 3 minutes with 15” of Hg or 380 mm of Hg.
Criteria: All blisters after checking should not contain water inside any pocket.