Pharmaceutical microbiology

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Pharmaceutical microbiology is an applied branch of microbiology . It involves the study of microorganisms associated with the manufacture of pharmaceuticals e.g. minimizing the number of microorganisms in a process environment, excluding microorganisms and microbial byproducts like exotoxin and endotoxin from water and other starting materials, and ensuring the finished pharmaceutical product is sterile. [1] Other aspects of pharmaceutical microbiology include the research and development of anti-infective agents, the use of microorganisms to detect mutagenic and carcinogenic activity in prospective drugs, and the use of microorganisms in the manufacture of pharmaceutical products like insulin and human growth hormone.

Contents

Drug safety

Drug safety is a major focus of pharmaceutical microbiology. Pathogenic bacteria, fungi (yeasts and moulds) and toxins produced by microorganisms are all possible contaminants of medicines- although stringent, regulated processes are in place to ensure the risk is minimal.

Antimicrobial activity and disinfection

Another major focus of pharmaceutical microbiology is to determine how a product will react in cases of contamination. For example: You have a bottle of cough medicine. Imagine you take the lid off, pour yourself a dose and forget to replace the lid. You come back to take your next dose and discover that you will indeed left the lid off for a few hours. What happens if a microorganism "fell in" whilst the lid was off? There are tests that look at that. The product is "challenged" with a known amount of specific microorganisms, such as E. coli and C. albicans and the anti-microbial activity monitored [2]

Pharmaceutical microbiology is additionally involved with the validation of disinfectants, either according to U.S. AOAC or European CEN standards, to evaluate the efficacy of disinfectants in suspension, on surfaces, and through field trials. Field trials help to establish the frequency of the application of detergents and disinfectants.

Methods and specifications

Testing of pharmaceutical products is carried out according to a Pharmacopeia of which there are a few types. For example: In America, the United States Pharmacopeia is used; in Japan there is the Japanese Pharmacopeia; in the United Kingdom there is the British Pharmacopoeia and in Europe the European Pharmacopeia. These contain a test method which is to be followed when testing, along with defined specifications for the amount of microorganisms allowed in a given amount of product.

The specifications change depending on the product type and method in which it is introduced to the body. The pharmacopoeia also covers areas like sterility testing, endotoxin testing, the use of biological indicators, microbial limits testing and enumeration, and the testing of pharmaceutical grade water.

Cleanrooms and controlled environments

Pharmaceutical microbiologists are required to assess cleanrooms and controlled environments for contamination (viable and particulate) and to introduce contamination control strategies. This includes an understanding of risk assessment. [3]

Risk management has been successfully employed in various industrial sectors like US Space industry (NASA), nuclear power industry and automobile industry which benefited these industries in several areas. But in application, the pharmaceutical sector is still in its infancy and the utilization of risk assessment techniques to pharmaceutical production is just beginning and the potential gains are yet to be realized.

Cleanrooms and zones are typically classified according to their use (the main activity within each room or zone) and confirmed by the cleanliness of the air by the measurement of particles. Cleanrooms are microbiologically assessed through environmental monitoring methods.

Viable monitoring is designed to detect levels of bacteria and fungi present in defined locations /areas during a particular stage in the activity of processing and filling a product. Viable monitoring is designed to detect mesophilic micro-organisms in the aerobic state. However, some manufacturers may have requirements to examine for other types of microorganisms (such as anaerobes if nitrogen lines are used as part of the manufacturing process). [4]

Surface methods include testing various Surfaces for numbers of microorganisms, such as:

• Product Contact Surfaces • Floors • Walls • Ceilings

Using techniques like:

• Contact Plates • Touch Plates • Swabs • Surface Rinse Method

For air monitoring, this is undertaken using agar settle plates (placed in the locations of greatest risk) or active (volumetric) air-samplers (to provide a quantitative assessment of the number of microorganisms in the air per volume of air sampled). Active air-samplers generally fall into the following different models:

• Slit to Agar • Membrane Filtration • Centrifugal Samplers

Monitoring methods will all use either a general purpose culture medium like tryptone soya agar (TSA), which will be used at a dual incubation regime of 30 °C – 35 °C and 20 °C – 25 °C or two different culture media are used at two different temperatures, of which one of the media is selective for fungi (e.g. Sabouraud Dextrose agar, SDA). The choice of culture media, incubation times and temperatures requires validating.

Professional guidance

The main sources of education and professional guidance for pharmaceutical microbiology come from Dr Tim Sandle's Pharmaceutical Microbiology Resources, Dr Scott Sutton's Microbiology Network, and the UK and Ireland Pharmaceutical Microbiology Interest Group (Pharmig).

Related Research Articles

Petri dish Shallow dish used to hold cell cultures

A Petri dish is a shallow transparent lidded dish that biologists use to hold growth medium in which cells can be cultured, originally, cells of bacteria, fungi and small mosses. The container is named after its inventor, German bacteriologist Julius Richard Petri. It is the most common type of culture plate. The Petri dish is one of the most common items in biology laboratories and has entered popular culture. The term is sometimes written in lower case, especially in non-technical literature.

Agar plate Petri dish with agar used to culture microbes

An agar plate is a Petri dish that contains a growth medium solidified with agar, used to culture microorganisms. Sometimes selective compounds are added to influence growth, such as antibiotics.

Cleanroom Dust-free room for research or production

A cleanroom or clean room is an engineered space, which maintains a very low concentration of airborne particulates. It is well isolated, well-controlled from contamination, and actively cleansed. Such rooms are commonly needed for scientific research, and in industrial production for all nanoscale processes, such as semiconductor manufacturing. A cleanroom is designed to keep everything from dust, to airborne organisms, or vaporised particles, away from it, and so from whatever material is being handled inside it.

Sterilization (microbiology) Process that eliminates or kills all biological agents on an object or in a volume

Sterilization refers to any process that removes, kills, or deactivates all forms of life and other biological agents such as prions present in or on a specific surface, object, or fluid. Sterilization can be achieved through various means, including heat, chemicals, irradiation, high pressure, and filtration. Sterilization is distinct from disinfection, sanitization, and pasteurization, in that those methods reduce rather than eliminate all forms of life and biological agents present. After sterilization, an object is referred to as being sterile or aseptic.

Disinfectant Antimicrobial agent that inactivates or destroys microbes

A disinfectant is a chemical substance or compound used to inactivate or destroy microorganisms on inert surfaces. Disinfection does not necessarily kill all microorganisms, especially resistant bacterial spores; it is less effective than sterilization, which is an extreme physical or chemical process that kills all types of life. Disinfectants are generally distinguished from other antimicrobial agents such as antibiotics, which destroy microorganisms within the body, and antiseptics, which destroy microorganisms on living tissue. Disinfectants are also different from biocides—the latter are intended to destroy all forms of life, not just microorganisms. Disinfectants work by destroying the cell wall of microbes or interfering with their metabolism. It is also a form of decontamination, and can be defined as the process whereby physical or chemical methods are used to reduce the amount of pathogenic microorganisms on a surface.

Microbiological culture Method of allowing microorganisms to multiply in a controlled medium

A microbiological culture, or microbial culture, is a method of multiplying microbial organisms by letting them reproduce in predetermined culture medium under controlled laboratory conditions. Microbial cultures are foundational and basic diagnostic methods used as a research tool in molecular biology.

An antimicrobial is an agent that kills microorganisms or stops their growth. Antimicrobial medicines can be grouped according to the microorganisms they act primarily against. For example, antibiotics are used against bacteria, and antifungals are used against fungi. They can also be classified according to their function. Agents that kill microbes are microbicides, while those that merely inhibit their growth are called bacteriostatic agents. The use of antimicrobial medicines to treat infection is known as antimicrobial chemotherapy, while the use of antimicrobial medicines to prevent infection is known as antimicrobial prophylaxis.

Blood culture Test to detect bloodstream infections

A blood culture is a medical laboratory test used to detect bacteria or fungi in a person's blood. Under normal conditions, the blood does not contain microorganisms: their presence can indicate a bloodstream infection such as bacteremia or fungemia, which in severe cases may result in sepsis. By culturing the blood, microbes can be identified and tested for resistance to antimicrobial drugs, which allows clinicians to provide an effective treatment.

Blow fill seal

Blow-Fill-Seal, also spelled as Blow/Fill/Seal, in this article abbreviated as BFS, is an automated manufacturing process by which plastic containers, such as bottles or ampoules are, in a continuous operation, blow-formed, filled, and sealed. It takes place in a sterile, enclosed area inside a machine, without human intervention, and thus can be used to aseptically manufacture sterile pharmaceutical or non-pharamceutical liquid/semiliquid unit-dosage forms. BFS is an advanced aseptic processing technology that is typically used for filling and packaging of certain sterile liquid formulations like liquid ophtalmics, inhalational anesthetics, or lavaging agents, but can also be used for injectables, parenterals, and several other liquid or semiliquid medications, with fill volumes ranging from 0.1...1000 cm³. Compared against traditional glass ampoules, BFS ampoules are inexpensive, lightweight, and shatterproof. Important BFS system suppliers are Weiler Engineering, Rommelag (Bottelpack), and Brevetti Angela.

A colony-forming unit is a unit used in microbiology. It estimates the number of bacteria or fungal cells in a sample which are viable, able to multiply via binary fission under the controlled conditions. Counting with colony-forming units requires culturing the microbes and counts only viable cells, in contrast with microscopic examination which counts all cells, living or dead. The visual appearance of a colony in a cell culture requires significant growth, and when counting colonies it is uncertain if the colony arose from one cell or a group of cells. Expressing results as colony-forming units reflects this uncertainty.

Limulus amebocyte lysate Chemical used for the detection and quantification of bacterial endotoxins

Limulus amebocyte lysate (LAL) is an aqueous extract of blood cells (amoebocytes) from the Atlantic horseshoe crab Limulus polyphemus. LAL reacts with bacterial endotoxin lipopolysaccharide (LPS), which is a membrane component of gram-negative bacteria. This reaction is the basis of the LAL test, which is widely used for the detection and quantification of bacterial endotoxins.

A particle counter is used for monitoring and diagnosing particle contamination within specific clean media, including air, water and chemicals. Particle counters are used in a variety of applications in support of clean manufacturing practices, industries include: electronic components and assemblies, pharmaceutical drug products and medical devices, and industrial technologies such as oil and gas.

Depyrogenation refers to the removal of pyrogens from solution, most commonly from injectable pharmaceuticals.

Barrier isolator is a general term that includes two types of devices: isolators and restricted access barriers (RABS). Both are devices that provide a physical and aerodynamic barrier between the external clean room environment and a work process. The isolator design is the more dependable of the two barrier design choices, as it prevents contamination hazards by achieving a more comprehensive separation of the processing environment from the surrounding facility. Nonetheless, both Isolator and RABS designs are contemporary approaches developed over the last 35 years and a great advancement over designs of the 1950s-70s that were far more prone to microbial contamination problems.

Bioaerosols are a subcategory of particles released from terrestrial and marine ecosystems into the atmosphere. They consist of both living and non-living components, such as fungi, pollen, bacteria and viruses. Common sources of bioaerosols include soil, water, and sewage.

Contamination control Activities aiming to reduce contamination

Contamination control is the generic term for all activities aiming to control the existence, growth and proliferation of contamination in certain areas. Contamination control may refer to the atmosphere as well as to surfaces, to particulate matter as well as to microbes and to contamination prevention as well as to decontamination.

Indoor bioaerosol is bioaerosol in an indoor environment. Bioaerosols are natural or artificial particles of biological origin suspended in the air. These particles are also referred to as organic dust. Bioaerosols may consist of bacteria, fungi, viruses, microbial toxins, pollen, plant fibers, etc. Size of bioaerosol particles varies from below 1 µm to 100 µm in aerodynamic diameter; viable bioaerosol particles can be suspended in air as single cells or aggregates of microorganism as small as 1–10 µm in size. Since bioaerosols are potentially related to various human health effects and the indoor environment provides a unique exposure situation, concerns about indoor bioaerosols have increased over the last decade.

Ultrapure water (UPW), high-purity water or highly purified water (HPW) is water that has been purified to uncommonly stringent specifications. Ultrapure water is a term commonly used in manufacturing to emphasize the fact that the water is treated to the highest levels of purity for all contaminant types, including: organic and inorganic compounds; dissolved and particulate matter; volatile and non-volatile; reactive, and inert; hydrophilic and hydrophobic; and dissolved gases.

Bioburden is normally defined as the number of bacteria living on a surface that has not been sterilized.

Inoculation needle

An inoculation needle is a laboratory equipment used in the field of microbiology to transfer and inoculate living microorganisms. It is one of the most commonly implicated biological laboratory tools and can be disposable or re-usable. A standard reusable inoculation needle is made from nichrome or platinum wire affixed to a metallic handle. A disposable inoculation needle is often made from plastic resin. The base of the needle is dulled, resulting in a blunted end.

References

  1. Saghee M, Sandle T, Tidswell E (editors) (2011). Microbiology and Sterility Assurance in Pharmaceuticals and Medical Devices (1st ed.). Business Horizons. ISBN   978-8190646741.{{cite book}}: |author= has generic name (help)CS1 maint: multiple names: authors list (link)
  2. Sandle, T. (2012). The CDC Handbook: A Guide to Cleaning and Disinfecting Cleanrooms. Surrey, UK: Grosvenor House Publishing. pp. 1–30. ISBN   978-1781487686.
  3. Sandle, T. & Saghee, M.R. (2013). Cleanroom Management in Pharmaceuticals and Healthcare. Passfield, UK: Euromed Communications.
  4. Based on definition from Environmental Monitoring.