The pharmaceutical industry operates under tightly controlled conditions. Since many of its products are injected into or ingested by humans, failing to keep production aligned with precise standards could create safety hazards that lead to illnesses and fatalities. Appropriate filtration is a significant part of keeping things running smoothly. They remove contaminants, keeping the medium consistently pure.
Here are some of the most frequently used pharmaceutical filtration methods.
What are the main pharmaceutical filtration methods?
Pharmaceutical decision-makers will choose various ways to filter their media depending on their specific needs. However, it’s important to remember that all filtration methods involve using a porous membrane that eliminates particulate matter from liquids or gases.
Surface Filtration
Surface filtration uses a membrane with specific-sized pores, allowing particles of a certain diameter through but trapping anything larger. This approach involves direct interception of the filter with the unwanted particles.
Depth Filtration
Depth filtration works similarly to surface filtration, but as its name suggests, it primarily removes particles further below the surface. Pharmaceutical professionals frequently use this method when working with solutions. This option relies on a thick cellulose-based filter that traps suspended particles and pulls them out of the fluid or gas.
Ceramic-filtered or sintered-metal filters are the most common types used during depth filtration. Cleaning sintered-metal filters without removing them is a key advantage that maintains productivity and high functionality.
Tangential Flow/Crossflow Filtration
This filtration technology purifies and separates biomolecules. It’s more commonly used in fields like microbiology than pharmaceutical processing, but it bears mentioning due to its versatility. It can clarify fermentation broths, harvest cell suspensions, and desalt or concentrate sample solutions.
The filtration occurs when a stream flows parallel to the membrane’s front. Applied pressure makes one part of the stream go through the filter while the remainder returns to the feed reservoir.
Nanofiltration
Nanofiltration is a tangential flow filtration that relies on a membrane with pores sized 1 nanometer or below in diameter. The associated applied pressure is much less than what tangential flow filtration requires, which can make the overall process more cost-effective by being less energy-intensive.
Magnetic Filtration
Pharmaceutical companies do not commonly use magnetic filters in production, but they may rely on them to remove heavy metals from water before recycling. This could help the business meet its environmental goals and show stakeholders it’s making efforts to operate more sustainably.
These filters work with magnetic force, so they require little to no energy. However, they don’t eliminate all metals, so companies primarily use them as one step in a multiphase process to remove contaminants.
Ultraviolet Purification
Some pharmaceutical filtration methods require multiple steps to get the desired results. Ultraviolet purification is an excellent example. It kills microbes and causes other contaminants to disintegrate through ultraviolet light exposure. However, people must use a secondary filtering method to eliminate the microbes destroyed by this method.
Recent research also suggests the combination of ultraviolet light and per acetic acid could enhance microbial water quality. Researchers tested this approach on purified water and water for injection, taking samples from 12 points within a pharmaceutical system. The results indicated the combined method was better at reducing microbial contamination than UV light alone.
Sterilised and Sterilisable Filters
The rush to create and distribute COVID-19 vaccines put logistics into the world spotlight. One of the main issues was that the virus was a global problem, but not every country had equal access to vaccinations. Some people were also wary of the vaccine because it was new.
However, public confidence rises when pharmaceutical companies have iron-clad processes that keep people safe. Sterilised and sterilisable filters are an important part of carefully regulated manufacturing procedures. For example, businesses may choose pre-sterilised filters to remove one step from their practices. However, other options work with autoclaves or gamma irradiation-based sterilisation machines.
Reverse Osmosis Filters
Reverse osmosis filters are some of the most effective options and are frequently chosen among pharmaceutical filtration methods. This approach uses a semi-permeable membrane that captures contaminants and allows the purified water to flow past the filter. They can remove virtually all pharmaceutical pollutants and often get optimal results. However, these are not the least expensive possibilities.
Choosing an appropriate pharmaceutical filter
People selecting pharmaceutical filters must consider several factors, including the particulate matter size and the ability to clean them. However, cleaning is not always necessary, especially considering the wide availability of single-use options. For example, single-use microcarrier filter bags use gravity to push materials through the filter media once someone feeds them through the top chamber.
People can also buy bag filters made of felt, which work for surface and depth filtration. Alternatively, propylene bags are common choices when chemical compatibility is a chief concern. Polyester versions can withstand high temperatures.
Woven cloth also serves as a filter for pharmaceutical filtration methods that use the cake approach. It relies on the cake formed on the membrane’s surface to increase efficiency. This method is a type of surface filtration where the medium runs through the cloth and the particles get caught in the holes.
People with authority over a pharmaceutical company’s budget must think about which filter types are most likely to get the best results during the scenarios it encounters most often.
Moreover, most companies use multiple pharmaceutical filtration methods for particular processes or products. Besides selecting the most appropriate options, people must maintain the filters properly and check them regularly for signs of fouling or other undesirable characteristics. Otherwise, they could gradually show degraded performance.
No universally best option among pharmaceutical filtration methods
These are some of the most common products and methods people use to meet their filtration needs. Individuals must study all pharmaceutical filtration methods carefully and select those that reflect current and future operational needs, budgets and the particulate matter to remove.
Knowing all those aspects is the best way to get optimal outcomes. People should also track any process changes that might require using a different filter type. Staying on top of such matters makes pharmaceutical companies remain within compliance.
