RIFAMPIN inhibits RNA synthesis by formation of a stable complex with the DNA-dependent RNA polymerase.
RIFAMPIN is metabolized in the liver and is a potent inducer of the P-450 enzymes. It can cause hepatitis and may color secretions red-orange.
PYRAZINAMIDE is only effective against M tuberculosis. It increases levels of serum uric acid.
The azoles are broad-spectrum fungistatic agents that inhibit the synthesis of ergosterol by inhibiting the 14-α-demethylase enzyme.
The polyene antifungals, AMPHOTERICIN B and nystatin, work by binding to ergosterol, the principal fungal membrane sterol.
AMPHOTERICIN B is most commonly used to treat serious disseminated yeast and fungal infections, particularly in immunocompromised patients.
Nystatin is too toxic for systemic use. Its use is limited to topical treatment for Candida albicans.
The most serious and most common toxicity of AMPHOTERICIN B is nephrotoxicity.
AMPHOTERICIN B is not absorbed from the gastrointestinal (GI) tract, so it must be given intravenously or topically.
Terbinafine is administered orally for treatment of superficial fungal infections.
Terbinafine and tolnafatate inhibit squalene epoxidase, resulting in the accumulation of squalene inside the fungal cells. Terbinafine is effective against the skin and nail fungi.
AMANTADINE is used for the prevention and treatment of influenza type A infections.
Primary metabolism: products of photosynthesis, which provide the food necessary if the plant is to live, grow and reproduce.
Secondary metabolism: very diverse and thought to provide secondary functions for the plant, such as protection against animals that might eat it or preservation again microbial attack, thus preventing decomposition. In some cases, secondary metabolites interact with symbiotic organisms. For example, cyanogenic glycosides made by sugars linking to highly toxic cyanide are released when the plant is attacked by an insect or disease-causing organism.
Good Manufacturing Practice (GMP)
GMP is generally defined as ‘that part of QA, which ensures that products are consistently produced and controlled to the quality standards appropriate to their intended use and as required by the marketing authorization’ (European GMP guidelines; WHO guidelines).
From this definition, there are a number of points that should be emphasized:
• GMP is part of QA. In other words, it is a preventative operation that is designed to make sure things happen in the correct manner. This means that, unlike QC, the quality of any operation can be affected by the GMP measures that are put in place.
• There is a requirement for consistency. It is no good producing a batch of product correctly one day, if there is no guarantee that the same result cannot be obtained every day.
• GMP relates specifically to the manufacturing aspects of a product pipeline. This is defined as the point from which starting materials are purchased from approved suppliers to the point where finished product leaves the factory. Indeed, there is also a responsibility to ensure the quality of the product during distribution, even though at this point it is often outside the control of the manufacturer.
• Quality standards should be appropriate to the intended use of the product. Hence the requirements to be fulfilled for the manufacture of an aseptically filled injection will be far more stringent than those for the manufacture of a multivitamin tablet.
• The standards are previously defined in the application for marketing authorization. Hence there is a clearly defined process by which each product must be manufactured.
Responsibilities under GMP
-There are ten elements in total, and these are described as follows:
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GMP is generally defined as ‘that part of QA, which ensures that products are consistently produced and controlled to the quality standards appropriate to their intended use and as required by the marketing authorization’ (European GMP guidelines; WHO guidelines).
From this definition, there are a number of points that should be emphasized:
• GMP is part of QA. In other words, it is a preventative operation that is designed to make sure things happen in the correct manner. This means that, unlike QC, the quality of any operation can be affected by the GMP measures that are put in place.
• There is a requirement for consistency. It is no good producing a batch of product correctly one day, if there is no guarantee that the same result cannot be obtained every day.
• GMP relates specifically to the manufacturing aspects of a product pipeline. This is defined as the point from which starting materials are purchased from approved suppliers to the point where finished product leaves the factory. Indeed, there is also a responsibility to ensure the quality of the product during distribution, even though at this point it is often outside the control of the manufacturer.
• Quality standards should be appropriate to the intended use of the product. Hence the requirements to be fulfilled for the manufacture of an aseptically filled injection will be far more stringent than those for the manufacture of a multivitamin tablet.
• The standards are previously defined in the application for marketing authorization. Hence there is a clearly defined process by which each product must be manufactured.
Responsibilities under GMP
-There are ten elements in total, and these are described as follows:
•
Defined processes: all manufacturing processes should be clearly defined during development and reviewed on an ongoing basis to ensure that they are appropriate and capable of consistently producing the required result.•
Validated processes: all critical steps within a manufacturing process should be validated when the product/process is first introduced and whenever there are any substantive changes made to that process. This ensures that the process not only performs consistently but also can be proved, with documented evidence, to do so.•
Necessary facilities: it is important that all the appropriate facilities are in place. In this context, facilities is defined in its widest sense as trained, qualified personnel; sufficient, suitable premises; appropriate equipment and services; materials, correctly labelled in appropriate containers; standard operating procedures, and other documenta- tion such as batch manufacturing records and batch packaging records; and appropriate arrangements for storage and transport.•
Clear documentation: manufacturing instructions and standards operating procedures should be clearly written in a manner that will be understood by the personnel for whom they are intended. They must be tailored to the specific facility in question.•
Trained operators: even with defined processes and clear documentation, manufactur- ing will not be carried out satisfactorily unless the operators are properly trained in all the necessary procedures.•
Appropriate records: all activities taking place during the manufacturing must be adequately recorded – if it is not written down, it did not happen. This documentation may be completed manually, or by electrical or electronic recording devices. In many companies, there is a mixture of both. However, in either case, there must be an effective control system for obtaining and maintaining these records. All process deviations must also be recorded and fully investigated before a batch can be released.•
Batch traceability: it is important that all manufacturing records are maintained in a suitable format so that full traceability is available. This particularly includes distribution records, which are critical in the case of a batch recall.