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Container closure integrity is essential for patient safety as well as pharmaceutical product efficacy, and container closure integrity testing (CCIT) is a critical step in the manufacturing process. A paradigm change is currently taking place in the pharmaceutical industry, moving it away from conventional probabilistic procedures and toward deterministic alternatives. LDA (a PTI Company) dives into the area of CCIT, giving the industry a thorough understanding of its practices and introducing innovative helium leak detection technology.

For non-porous packaging including vials, syringes, and cartridges, helium mass spectrometry has become the new leak detection standard. The approach is favored by producers and authorities because of its greater sensitivity, quicker test times, traceability, and determinism in contrast to the probabilistic conventional methods.

Role of Helium Mass Spectrometry in Leak Testing Vials

Helium mass spectrometry is a leak detection standard for various pharmaceutical packaging formats, including vials. Mass spectrometer leak detector is an equipment often used for discovering and identifying leaks within or outside the product. Typically, it works with a vacuum chamber and a closed container filled with helium. Helium leakage from the container is measured by the mass spectrometer. In this technique, the product connected to the detector is filled with helium tracer gas. Helium from the tested product escapes into the detector, where it is measured and indicated as partial pressure.

The sector field mass spectrometer works as the fundamental component of leak detection. Helium gases are ionized as they enter the vacuum. Next, voltage is added to accelerate the helium ions, which are subsequently separated in a magnetic field. A specific detector is used to change the ion current into an electric current. Utilizing leak detecting units, this current is accelerated and displayed on the screen. The leak will be determined by the current since it is directly proportional to the helium concentration.

Why is Helium Used in Leak Detection?

• It is an inert gas molecule that is among the smallest.
• It may consistently and readily breach pathways due to its small atomic size.
• Helium is non-toxic, non-condensable, and non-flammable.
• Relatively safe to use as it will not interact with the components being tested.
• Helium is less expensive and readily available when compared to other tracer gases.
• There is no more than 5 ppm of helium in the atmosphere.

For Maximum Allowable Leakage Limit (MALL) testing in the pharmaceutical industry, LDA helium leak detection technologies are ideal. It is crucial that you control the tracer gas concentration while doing the measurement to guarantee accuracy. This is particularly challenging when working with vials or other sealed containers. Therefore, LDA (a PTI company) provides solutions to test the integrity of pharmaceutical vials.

Maintaining the integrity of products from the time it is manufactured to the time it is distributed to the patient is a great challenge. Liquid pharmaceuticals, capsules, and formed tablets are typically packaged in bottles. To assure the quality of these items, leak testing is carried out on each bottle to ensure that it does not leak. Testing pharmaceutical bottles or pharmaceutical package leak detection before filling is a critical step in ensuring the integrity of the container.

Helium leak testing is one of the most sensitive Container Closure Integrity (CCI) testing techniques that can be applied to pharmaceutical bottles for testing quality. Helium is used as a tracer gas, and the quantity of helium leaving through the package is measured and stated as leak rate. Since it is non-toxic, non-flammable, and non-condensable, helium is an ideal tracer gas for finding leaks. Its atmospheric presence is restricted to 5ppm. Due to its tiny atomic size, helium can easily pass-through leaks. Helium is also safe to use since it does not react with the materials of the components under test.

Significance of Helium Mass Spectrometry in Leak Testing Pharmaceutical Bottles

Helium mass spectrometry is a leak detection standard for pharmaceutical containers including bottles. Helium mass spectrometer, a commonly used instrument detects and locates tiny leaks. It usually works with a vacuum chamber and a sealed container filled with helium. A mass spectrometer detects the rate at which helium is leaking out of the container. This method uses tracer gas - helium to fill the product attached to the detector. The tested product leaks helium into the detector, where its partial pressure is measured and displayed.

The leak detector's principle is based on a sector field mass spectrometer. In vacuum, entering helium gases are ionized. The helium ions are then accelerated by adding voltage and then separated in a magnetic field. The ion current is converted to an electric current by using a particular detector. This current is accelerated using leak detection units and displayed on the screen. The current measured will be directly proportional to the concentration of helium and therefore equal to the leak measured.

Applications of Helium Leak Detection

• Ensure container closure integrity.
• Seal integrity monitoring during stability studies.
• Verify and predict shelf-life seal integrity.
• Useful in the early stages of the development of a pharmaceutical product packaging system.
• Closure formulation and configuration selection.

Bottles are useful in the healthcare industry, hence evaluating them is a challenging task nowadays. These containers are extremely difficult to test, however, helium leak detection can be used to qualify them prior to use or as a proof of concept. LDA provides professional engineering solutions for the Active Pharmaceutical Ingredient (API) sterile container testing.

Helium Leak Testing is used to locate and identify extremely tiny leaks in any component that can produce a differential pressure. Helium Leak Rate can be expressed quantitatively (the quantity of leak rate). The helium leak testing method is also used to examine the performance of a component or system, as well as to study or evaluate the lifetime of a product. Helium gas is primarily utilized as a leak testing medium due to its ability to detect and quantify leak rates at very low levels.

LDA offers various helium leak testing services for pharmaceuticals and medical devices. The services are as follows:

Leak Testing Services

• Installation & Quality Assurance of Helium Leak Detector

Leak Detection Associates guarantees that each custom instrument comes with comprehensive service delivery, installation, and validation program that is appropriate for the regulated environments in which the instruments will be used. Prior to delivery, the LDA Engineering Technician will collaborate with delivery site personnel to confirm that the location has the appropriate gas and electrical supplies for instrument functioning. Once the instrument is on-site and in the position specified by the customer, the Engineering Technician will perform a formal Installation Qualification (IQ), Operation Qualification (OQ), and Performance Qualification (PQ). Prior to execution, these can be pre-approved by local Quality Assurance.

• Helium Leak Detector Service Agreement

Leak Detection Associates recognizes that maintaining instrument performance is an important part of the business’s success. While the instruments offered by LDA are simple to use and maintain, it helps to improve productivity by proactively guaranteeing performance with an LDA Annual Service Agreement. Leak Detection Associates provides service contract plans that are customized to the unique needs and specifications. The following are examples of key components of any service program:

1. Repair and replacement parts are available on-site at no additional charge

2. Annual On-Site Preventative Maintenance

3. Detailed Annual Requalification & Calibration

•  Helium Leak Detector Calibration Services

Annual calibration services for all components of the test system, including internal and exterior leak standards and HSAM probes, are also available as an alternative to a full-service contract. Failure to calibrate the leakage criteria may result in a decrease in the accuracy and validity of the results over time, as well as concerns of individuals working in a CGMP or other controlled environment. A complete calibration program at regular intervals is designed to ensure proper instrument readings for the life of the device with minimal instrument downtime. LDA can set reminders when service is required once in our calibration database, ensuring that SIMS 1915+ does not skip a beat.

• Training for Helium Leak Testing

Leak Detection Associates offers on-site training relevant to how the SIMS 1915+ Helium Leak Testing device will be utilized, with the objective of being a comprehensive solutions provider to the clients. More sophisticated parts of leak testing, as well as system care and maintenance, can be covered in training programs. The Leak Detection team has over 20 years of hands-on expertise and can help the organization with anything from basic knowledge and understanding of leak testing basics to specialized leak test method development and validation.

• Helium Leak Detection Feasibility Studies

LDA offers dependable feasibility and method development services. Prior to procuring an instrument or moving on with outsourcing solutions, feasibility services can provide proof of concept for its intended usage, or they can assist to expand existing capabilities by designing solutions for new package systems. LDA also provides full method development utilizing industry-standard positive control techniques in the cases where clients do not have internal resources experience in the development of helium leak detection tests, or where current resources need to be expanded. Methods created at LDA can be transferred and verified at the client site, or they can be utilized frequently at LDA for lab-scale, non-cGMP research.

• Onsite or In-House CCI for Package Systems

LDA offers testing capabilities at both the client's site and our location. A SIMS 1915+ purchased and installed in a controlled context can be used for client onsite testing. With hands-on expertise in cGMP and regulated laboratory and production environments, documentation procedures are quite often in line with internal and external quality standards. LDA also provides the option of bringing one of our test units to a client's site for particular investigations. In-house testing is an alternative for clients looking to analyze package systems or designs on a contract basis.

LDA provides its customers with the highest quality of services. We are the world's leading manufacturer of high sensitivity helium-based leak detection systems for the pharmaceutical and biologic industries. Our engineers and support staff are highly trained and certified, allowing us to provide professional services across a wide range of testing domains.

Blister packages are a convenient format for users and a practical way to keep tablet and capsule quality preserved. The majority of blister package applications are considered low-risk, and they do an excellent job of protecting pharmaceutical products from moisture intrusion, which can cause product degradation. Tablets with a hydrophilic nature, or a natural tendency for absorbing moisture, require extra protection.

Due to an increase in the number of hormone-based and steroidal therapies in recent years, worries concerning the integrity of blister packing have emerged. Given their propensity to degrade and impair treatment outcomes, packaging these and other groups of pharmaceutical products is considered a high-risk application. To combat this, most manufacturers choose a totally aluminum, cold-formed package, which offers the best protection against oxygen penetration, while some industries have packaged very sensitive steroidal therapies in thermoformed blister packaging. As these products are more susceptible to environmental conditions than most other tablets and capsules, it is critical to inspect for tiny leaks, regardless of the packaging utilized in this high-risk application.

Limitations of Blue Dye Test

One or more blister packs are submerged in a chamber holding blue liquid and a vacuum is drawn to conduct the blue dye test. The chamber is then restored to atmospheric pressure, and the packages are retrieved and examined to determine if any dye has entered them. No defect is detected if there is no dye in the blister packaging. The blue dye only enters the package after the vacuum phase, which is the major defect of this method. As a result, when the chamber is returned to atmospheric pressure, nothing prevents the operators from removing the packages from the dye during this final stage.

Package headspace and dye surfactant concentration are the other difficult factors to control in the blue dye test. In reality, the test just determines how easily or quickly the dye may enter the blister cavity. It does not tell you about oxygen or vapor intrusion. This is a significant disadvantage since gaseous pollutants may penetrate foil and film more readily through a tiny leak, which is subject to surface tension. This requires a relatively large single passage to enter the package. Another major disadvantage and difficulty to control is the subjective nature of the operator's inspection.

Leak Testing Blister Packages Using Deterministic Test Method

Helium leak testing is a deterministic method for identifying package leaks in blister packs using helium as a tracer gas. The change in its concentration is measured as it escapes due to leakage. The quantity of helium that escapes from the package is expressed as a leak rate. Helium leak detection is a very sensitive technique for testing pharmaceutical package integrity.

Seal Integrity Monitoring System (SIMS) 1915+ is the optimum leak detection system using helium. When compared to traditional methods such as vacuum bubble and dye penetration test, packages may be quantitatively examined with high accuracy. This method enables a comparison of different packaging materials and forms, as well as production line settings and storage conditions, thus supporting the entire life cycle. Package design, tooling qualification, production line setup and ongoing product quality monitoring are the applications that come under SIMS 1915+. It is specially designed for the pharmaceutical and medical device industries.

Blister packaging is a type of pre-formed plastic packaging that includes a base card with artwork and a clear plastic pocket called the blister. The cavity, which is composed of either plastic or aluminum foil, and the lid, which is made of paperboard, paper, plastic, or aluminum, are the two main components of blister packaging. The product is enclosed in the cavity, and the lid seals the package. Blister packing is used in the pharmaceutical industry to pack tablets, pills, capsules, granules, and lozenges. Blister packaging gets its name from the fact that each item is kept within its own small plastic bubble or blister. Blister packs can provide tamper resistance as well as barrier protection for shelf-life requirements.

Due to its extreme sensitivity, a helium-based test method is used for verifying the integrity of the blister pack. The test method operates by detecting helium that has been enclosed in the package system and is escaping through micro-channels in the package. This test sequence begins with the package being placed in the test fixture and immediately drawing a vacuum. The helium thus escapes through potential holes or cracks in the packaging as a result of the pressure differential.

Blister Pack Leak Testing Using Helium Mass Spectrometry

The Mass Spectrometer Leak Detector is a comprehensive system for locating and detecting leaks within or outside of product. This approach employs the use of helium as a tracer gas, which is utilized to fill the product attached to the detector. Helium leaks into and out of the tested product, causing its partial pressure to be measured and shown on a screen.

The leak detector works on the principle of a sector field mass spectrometer. Helium gas is ionized in a vacuum. Helium ions are accelerated and separated in a magnetic field using additional voltage. The ion current is converted to an electric current using a specific detector. The current is accelerated by leak detection units and displayed on the screen. The measured current is proportional to the helium concentration and equal to the observed leak. Helium leak detection using helium mass spectrometry is widely known for its suitability for packaging such as blister packs.

Helium Leak Detection Benefits

• With a high degree of sensitivity, leaks can be identified and measured
• No effect on the materials under test, due to the inert properties of the helium
• The testing procedure is mostly dry and temperature-independent
• Helium leak testing has a faster cycle time, which reduces the cost and overall processing time

Helium leak detection offered by Leak Detection Associates (LDA) can greatly improve the safety and health of blister package users. Blister packaging ensures that tablets and capsules are properly sealed. It is simple to do a leak test after packaging. Blister packaging is popular because of its convenience of packing, easy dosing for the patient, with its popularity increasing for many new drug solid dose/oral dose products.

Using helium as a tracer gas is the most sensitive and commonly used tracer gas leak detection technique for CCI. When moisture-sensitive pharmaceutical products are lyophilized, their shelf life is extended, and they are better prepared for storage and transportation. A lyophilized medicinal product's quality is ensured by maintaining consistent moisture content. Proper container closure system (vial, stopper, seal) selection and sealing conditions are equally important factors. Demonstrating Container Closure Integrity (CCI) is one way of achieving this goal.

Why use helium?

Helium gas is one of the smallest molecules. In addition to being non-flammable, non-destructive, non-toxic, and inert, helium only has a trace presence in the atmosphere. Helium is generally safe to employ (compared to hydrogen) since it will not react with any of the components in the test part. Mass spectrometers detect helium in the vast majority of leak testing applications. A residual gas analyzer, on the other hand, is also an option. In general, helium leak testing ensures higher levels of sensitivity than conventional pressure decay methods.

Tracer gas method to test seal integrity

Tracer gas leak testing is a simple and very effective way of detecting leaks that offer great sensitivity, accuracy, and repeatable results. Being one of the most effective method of leak detection, tracer gas leak testing offers great sensitivity and accuracy. Micro-leaks between 1x10-4 to 10-9 scc/s can be detected using the tracer gas leak test, which utilizes the tracer gas - helium. Tracer gas leak testing can be done with either pure helium or by mixing it with another gas such as nitrogen or dry air to reduce the overall cost. A mass spectrometer is used in the standard test method for measuring package and seal integrity. Due to its low concentration in the atmosphere, and its detection using a mass spectrometer, helium is employed. It is done by injecting helium into sealed packages or adding it to sealed package’s headspace after sealing. In the following step, a mass spectrometer is used to identify and measure the presence of helium in the surrounding enclosed space.

Vacuum test method is the commonly employed tracer gas method for testing the seal integrity of pharmaceuticals products. In this method, seals are put under stress by a vacuum, which measures tiny leaks. Helium transfer rate captures the real transmission rate through the material as well as via the seals. Transmission of helium through the material as well as seals is captured by helium transmission rate. As a result, the vacuum technique is more effective in detecting leaks since it monitors helium gain in the external environment within the enclosed sample.

When packaging seals are tested for integrity, it helps guarantee that the packaging offers necessary product protection for patient safety. To ensure product quality, package seals must be reliable. Seal integrity tests are commonly used to evaluate sustainable packaging options, lower-cost packaging, and changes in manufacturing line sealing parameters, among others. Evaluating the seal strength of packing materials with reduced costs and alternative sealing procedures confirms that the seals do not leak over time.

Leak Detection Associates (LDA) designs and manufactures high-performance tracer gas (helium) leak detection systems to ensure the integrity of seals for the pharmaceutical and biological industries. Helium leak detection is the one of the most effective leak detection method to identify and locate leaks in a closed system.

In World War II, helium mass spectrometry was used in Uranium enrichment plants for leak detection. This approach is still in use today, with some adjustments, as it is regarded to be one of the most accurate ways for locating leaks. Helium gas is utilized in this approach as a tracer gas. This occurs when helium leaks in/out of the tested product and enters the detector, where its partial pressure is recorded and shown on a screen. Leakage is detected using an instrument called a Helium Mass Spectrometer, which also measures the rate of leakage.

Principle of helium leak detector

Leak Detector works on the concept of a sector field mass spectrometer. Containers that need to be tested for leakage are usually filled with Helium and put in a vacuum chamber. The tracer gas helium is ionized in a vacuum after analysis. With the addition of voltage, helium ions are accelerated and then separated in a magnetic field. Using a particular detector, the ion current is converted to an electric current. Leak detecting units accelerate the current and display it on the screen. Helium concentration determines the measured current, which is equivalent to the measured leak.

What makes helium suitable for leak detection?

Due to its numerous advantages, helium is the ideal choice for leak detection purposes.

• Non-toxic and non-flammable
• Inert and non-condensed
• Low cost
• Due to its low atomic mass, it can easily pass through even very small leaks
• Present in the atmosphere, only in trace amount

Leak detection methods using helium mass spectrometer

There are two primary methods of testing: vacuum testing and pressure testing. The goal is to find the leak and determine how much or how fast it is leaking. When using either technique, it's vital to maintain circumstances that are comparable to what the system would encounter in real life.

As part of the vacuum testing, the leak detector is inserted into the system or product that has to be tested for leaks. In order to remove air from a system and create a vacuum, a pump is utilized. Helium is then sprayed on locations where the leakage is likely to occur. Spraying should be done with proper care to ensure that no portion of the body is skipped. As soon as the detector detects a leak of Helium, it alerts the user. This approach is also known as the spray probe method, or the spray probe technique.

Under pressure testing, the product must be placed within a vacuum chamber that has been properly constructed. Helium is pumped into the chamber, and the detector is used to check for leaks. This method is also known as the sniffer probe method. Helium filled system put in a chamber with a detector attached to a vacuum pump is another mode of this approach for determining leakage rate. If there is a leak, Helium will leak out of the pump and the detector will calculate the rate of leaking once the pump is running.

Helium mass spectrometry can be used in a variety of ways to discover extremely small leaks.