Pharmaceutical Microbiology - Essay Example

Pharmaceutical microbiology al affiliation Disinfectants Introduction Disinfectants are agents that are used to destroy micro-organisms that live on non-living objects. Compared to sterilization, disinfectants are less effective. Disinfectants offer microbiological sterilization without harming human beings and useful living organisms, are cheap, easily acquired and are non-corrosive. Disinfectants have different modes of action and their efficacy of disinfectants depends on mode of application and the kind of material to which they are applied. Types of disinfectants and mode of action Aldehydes Formaldehyde is commonly used as a form of gas or vapour in solution in water. The mode of action for formaldehyde is to interact with the protein, DNA and RNA since it is extremely reactive. It is able to penetrate in the interior of the bacterial spores. This interaction with protein results from a combination with the primary amides and amino groups. Formaldehyde also acts as an alkylating agent by reaction with hydroxyl groups, carboxyl and sulfhydryl. It forms protein-DNA crosslinks therefore inhibiting synthesis of DNA. Phenols This is one of the oldest disinfectants and antiseptics used in hospitals. Phenol acts suitably during mitosis when bacterial cells are more sensitive. Phenols mode of action is by damage to the plasma membrane leading to intracellular constituents being leaked progressively in addition to release of potassium ions. Alcohols Alcohols display a rapid broad spectrum of antimicrobial activity against bacteria, viruses and fungi. Alcohols are basically used as antiseptics and disinfection of hard surfaces since they reversibly inhibit sporulation. When combined with water, alcohols become more effective since diffusion inside the cell through the cell membrane is facilitated. Alcohols cause membrane damage and rapid protein denaturation followed by interference with metabolism and cell lysis. Chlorhexidine It is a biguanide used both as an antiseptic and disinfectant because it is effective in a wide spectrum and has a low irritation on skin. Its mode of action is by damage of the cell membrane then passage of the agent through passive diffusion and destroys the bacteria or yeast cytoplasmic membrane. Its efficacy is dependent on pH and is greatly reduced in organic matter. Hydrogen peroxide Hydrogen peroxide is used for disinfection, antisepsis and sterilization. It is a clear and a colourless liquid that is commercially available in various concentrations. It can degrade in water and oxygen therefore it is considered environmentally friendly. Hydrogen peroxide has a broad spectra of efficacy against bacteria, viruses and yeast. Hydrogen peroxide produce hydroxyl free radicals which attack essential cell components, such as lipids, proteins and DNA. Conclusion Micro-organisms can adapt to different environmental physical and chemical conditions. It is evident that disinfectants vary significantly from their mode of action and factors that affecting their efficacy. Disinfectants can be selected based on particular circumstances or nosocomical outbreaks. Steam autoclave Introduction A steam autoclave is a large pressure chamber used to sterilize equipment by subjecting them to high pressure saturated steam at required temperature, about 121 ̊ C for a specific time depending on the size of the load and contents. This method is non-toxic, cheap, and rapidly microbicidal and sporicidal. However, steam has negative effects on materials such as corrosion. There are two types of autoclaves, the gravity displacement autoclave and the high-speed pre-vacuum cleaner. Steam autoclaves are mostly used to sterilize hospital equipment. Design, operation and monitoring of steam autoclave Steam enters a chamber jacket, then passes through n operating valve and enters the rear chamber behind a baffle plate. It flows forward and down through a chamber and load and exits from the front bottom. The jacket and chamber pressure is maintained by a pressure regulator. A safety valve provides protection against overpressure. An autoclave uses steam under pressure to sterilize equipment. The steam reaches high temperatures due to high pressure therefore increasing its heat content and killing power. The heating power of the steam is derived from its latent heat of vaporization and the amount of heat is required to convert boiling water to steam. Steam condenses rapidly to water when in contact with cooler surfaces thereby penetrate objects. This creates a negative pressure at the condensation point and draws more steam to the area. As long as the condensing surface has less temperature than that of the steam, condensation of the steam will continue until the temperatures equilibrate. Effective autoclaving is achieved with high and even moisture content. The ability of air to carry heat is directly related to the amount of moisture present in the air. The more the moisture, the more the heat therefore steam is results to killing of the cells and coagulation of protein, killing microorganisms. Death is also caused by accumulation of irreversible damage to all metabolic functions of the organisms since the vibrating motion of every molecule induces the cleavage of intramolecular hydrogen bonds between the proteins. The steam cycles should be monitored by mechanical, chemical, and biological monitors. They steam autoclaves are usually monitored using printout by measuring temperature, the time at the temperature and pressure. Chemical indicators are fixed to the outside and incorporated into the pack to monitor the temperature or time and temperature. A biological indicator is also used to monitor the effectiveness of the autoclave. Factors affecting the sterilization process The effectiveness of the process of sterilization depends on the thermal death time that is the time microbes must be exposed to a particular temperature before they are destroyed. The thermal death point or temperature at which all microbes in a sample are killed is also an important factor. The presence of moisture also significantly affects the coagulation temperature of proteins and the temperature at which the organisms are destroyed. Conclusion To ensure that autoclaves are effective against bacteria, the steam needs to be in direct contact with the objects that need to be sterilized. The air present in the autoclave should be displaced by creating a vacuum and replaced with steam. A well control scheme must be designed for the expulsion of steam so that the objects may not be destroyed. Steam autoclaves can be used on items that are resistant to heat and moisture. Microbiological analysis of sterile pharmaceutical products. Introduction It is a regulatory requirement to test sterile products microbiologically in a pharmaceutical industry. There are several ways which drug products can be contaminated and the only way to ascertain that a given product is sterile, it has to undergo testing. Sterility assurance is important in the manufacture of drugs and other medicinal products to determine the probability of a product having viable microorganisms after application of a valid sterilization process. The sterilization process could be by heat or ionizing radiation on heat and radiation tolerant components while filtration may be used on other products on the final container at the end of the manufacturing process. To ensure sterility there should be validation and control of the sterilization process and of aseptic processing procedures. Sterility is only able to detect relatively high levels of contamination in a given product. A sterility test ensures that a sterilized pharmaceutical product is free from micro-organisms that are contaminating. Factors affecting microbiological analysis Accidental contamination This is done by culturing any viable microorganisms in the sample considering the environment of the laboratory. It is possible to obtain false positive results due to contamination. Exceptional skill, an in-depth specific knowledge and rigorous usage of positive and negative controls. Environmental conditions There are potential risks such as temperature environmental pressure, vibration may affect the sterility of the intermediate products during storage or transportation. These factors should be identified so as to provide an acceptable working condition. Environmental monitoring should be monitored to prevent environmental deterioration and product contamination. Storage and transport of sterile products Storage of sterile products should be done appropriately so as to maintain the sterility of the products. The containers should be able to isolate the products from the surrounding non-sterile environment. The containers should be cleaned and sterilized before being filled with transporting material. Validation The sterile pharmaceutical products should be validated through a harmonized application of hardware such as well-designed facilities and software. This should also include validation of raw and other materials supplied by external sources and maintenance of sterility during transport. Untrained personnel Untrained personnel may fail to maintain discipline and strict supervision that may provide a quality appropriate for sterility assurance of the final product. Trained personnel may minimize risks such as using appropriate sampling techniques. Conclusion Every pharmaceutical company is expected to develop microbial specifications for their non-sterile products. Factors affecting the microbiological analysis of pharmaceutical products should be considered so as to ensure efficacy. Humans as a source of microbial contamination Humans are a major source of contamination since they generate particles from the skin, lint, cosmetic and respiratory emissions. For instance, human hair has a diameter of about 75 microns and dandruff that can be a contaminant. People’s behavior in terms of behavior such as rate of movement, sneezing and coughing and attitudes in work habit and communication between workers can produce contamination. Fingerprints contain sodium, potassium, chloride and phosphorous. Perspiration also contains sodium, potassium, chloride, sulfur, aluminum, carbon, and nitrogen. Control Contamination can lead to increased costs in production. Therefore several measures must be put in place to ensure minimum contamination. Certain protocols must be made to ensure a contamination free clean room. Training people accessing the clean room All operators must be properly trained in occupational skills, knowledge of the product and all the aspects of the production process, and the unique practices and behaviors required for working in the clean room environment. The operators should be tested to ensure that the training has been implemented and is effective. The personnel should ensure personal hygiene and avoid application of make-up. They should be trained on the different components that may contaminate the clean room. Training should also encompass the importance of keeping a clean room free from the contamination and the impact on efficacy. Clean room garments These are masks, gloves, and head masks are used in every environment. Jump suits are required in very clean environments. The garments vary from one clean room to another. Appropriate clean room fabric should be determined and fabric evaluated for small pore size to strain particles form passing through, the comfort of the wearer and durability. Prohibition of certain personal actions Fast motion such as running and walking fast, sitting or leaning on equipment, writing on equipment or garments, wearing clean room garment outside the cleanroom and wearing torm or soiled garments should be prohibited. General clean room regulations For a successful operation in the general cleanroom, regulations should be set up. For instance, personal items such as keys, watches should be placed in a locker room outside the clean room. There should be no eating or drinking or chewing gum. Garments that are allowed inside the room should only be permitted. No cosmetics are allowed in the clean room. Only approved cleanroom paper and ball point pens should be allowed. Moreover, gloves or finger cots should not be allowed to touch any item or surface that has been thoroughly cleaned. Certain habits such as scratching and hand rubbing should be discouraged. All doors must remain closed when not entering or exiting. A cleaning management program should be established to ensure the room is cleaned using appropriate cleaning materials, equipment and cleaning agents. In conclusion, it is the duty of people accessing the clean room to ensure minimum contamination in the area by abiding to the rules and regulations. How the design and the operation of clean rooms achieves this purpose by minimizing microbial contamination from non-human sources Introduction A clean room is one that has been specifically constructed and has environmental controlled places with respect to air particles, temperature, humidity, air pressure, and vibration, lighting and living organisms. In pharmaceutical manufacturing processes, clean rooms control living particles that would produce undesirable bacterial growth in preparation of biological, pharmaceutical and other medical products. The sources of contamination could be either internal or external. External sources are through atmospheric contamination through the air conditioning system. Contamination could also infiltrate through doors, windows, pipe penetration, cables and cracks. It is controlled by high efficiency filtration, space pressurization and sealing of space penetrations. Humans are the largest sources of contamination in a clean room. Other internal sources of contamination could be generated through combustion, chemical and manufacturing processes. The airflow design is critical and it controls the clean room. The construction materials that make the walls, floors, ceiling tiles, lighting fixtures, doors and windows should be carefully selected to meet the clean room standards. In the design, supplying sufficient volume of airflow and cleanliness to support the cleanliness rating of the room should be considered. In addition, air must be introduced in a manner to prevent stagnant areas where particles should accumulate. Air conditioning design should meet clean room temperature, humidity and filtration requirements. Enough conditioned make-up air should be ensured to maintain the specified positive pressurization. A clean room has increased air supply to control particles. A clean room should have at least ten air changes to 600 per hour to ensure absolute cleanliness. The large air supply is mainly provided to eliminate the settling of particulate and dilute contamination produced produced in the room to an acceptable concentration level. The room also uses high efficiency filters are used to filter the supply air into a clean room to ensure the removal of small particles. The high efficiency filters used in clean rooms are installed at the point of air discharge into the room. Room pressurization is basically provided to ensure that untreated air does not pass from contaminated areas that are adjacent to the clean room. It is done by supplying more air and extracting less air from the room than is supplied to it. Clean rooms have filtration which is a vital aspect. Most filters are defined by their particle removal efficiency and rate of airflow. Filters use mechanisms to remove contamination from the air streams. Particles larger than the passages between the fibers cannot pass through and are collected in media in sieving or straining. Particles can leave the mainstream around the filters and impact the fiber directly. The particles are retained by adhesives in inertial or impaction where the particles leave the airstream around filters through inertia. In diffusion, the particles are small enough and have low mass so that air molecules which are continually in motion and are bombarding particle which cause the particle to acquire a vibration mode. This vibration mode causes particles to get in contact with the fibers. In order to design a clean room airflow, one has to identify the kind of cleanliness required. Clean rooms are important to ensure the control of particulate and microbial contamination. All aspects such as efficiency of filtration, type of air handling equipment, ceiling coverage, air changes, flow patterns, pressure difference must be properly evaluated. Read More