6 Reasons To Consider HVLD vs. Vacuum Decay For Pharma Products
It’s no surprise that the container-closure system for any pharmaceutical product plays an essential role in ensuring that drug’s stability and sterility. Container-closure integrity is the ability of the system to keep contents in and to keep harmful environmental contaminants out. It consists of the components intended to seal and protect the package/delivery system and its valuable contents.
In pharmaceutical and food packaging, there are multiple methods widely used to test if these container-closure systems pose any risk of leakage from pinholes, cracks, or defective seals. These tests range from vacuum or pressure decay tests, to submerging the entire container into a dye solution under pressure and visually inspecting the container for the presence of dye, to more advanced vision systems that inspect for certain defects in the container. Let’s compare two of the more common methods: high voltage leak detection (HVLD) and vacuum decay.
1. PRECISE DETECTION CAPABILITY
First and foremost, the detection capability is much more precise with an HVLD system compared to one using vacuum decay. HVLD is consistently capable of detecting a pinhole of 5µ or smaller defect, whereas vacuum is only capable of detecting a pinhole of 20µ and larger on a consistent basis.
2. BETTER REPEATABILITY
It has been proven through customer experiences that HVLD is by far the more repeatable inspection method when using defective samples for validation (i.e., 5µ defect samples created by a laser). Compared to HVLD systems, vacuum systems are less repeatable because of the external pressures placed on the containers within the inspection chamber. When large amounts of external pressures (close to 1 atmosphere) are applied to the container, the defective area can act like a “membrane” and physically move to close the defect, thereby making it undetectable. HVLD does not apply any external pressures to a package during inspection and does not rely on the measurement of flow rate. Also, it’s not necessary to have a product leaking through a hole in order to detect the defective area — HVLD does not depend on the vaporization of the product under pressure. The high voltage will pass through the hole/defect to the product, thereby changing the current characteristic which allows the HVLD system to detect the defect within the inspection area.
3. EASY, LESS EXPENSIVE MAINTENANCE
Equipment maintenance is much less difficult with HVLD systems. There are very few movable parts, which only need minimal daily or even yearly maintenance. HVLD systems do not use inspection chambers, which require seals that are a consumable part and a high-maintenance item. Inspection chambers also must be validated, which requires an extreme amount of testing time. Additionally, the rotary table used in a production vacuum unit has many moving parts and requires more elaborate yearly maintenance that brings with it high labor and parts costs.
Annually, it costs approximately 80% less to maintain an HVLD system compared to a vacuum system.
4. LOWER UTILITY COSTS
Considering there are no large vacuum pumps necessary with an HVLD system, the utility-related costs to run an HVLD system are lower.
5. SMALLER FOOTPRINT
Machine size is a large factor when designing your packaging area. The HVLD system typically requires less floor space than is required by a vacuum system.
6. QUICKER VALIDATION TIME
Validation time is always a concern when implementing any type of pharmaceutical or food processing system. Since HVLD systems do not have individual inspection chambers to validate, the process is very simple and requires less time and effort to complete validation. Several of our customers have validated their HVLD system for a single product within a 2 to 3 week time frame.
In conclusion, HVLD is simply more cost-effective to install, validate, and maintain.
Source: Nikka Densok USA, Inc.
By Brian Ball, President, Nikka Densok USA
