Glossary of Terms - V

Vacuoles
Membrane-bound organelles of low density responsible for food digestion, osmotic regulation, and waste product storage. Vacuoles may occupy a large fraction of cell volume (up to 90% in plant cells).

Vaccine
A preparation of microbial antigens that provokes an immune response (i.e. the production of antibodies) on injection, thus conferring immunity on the recipient. There are three types of vaccines:

1. Those containing material from a nonvirulent organism that retains its immunogenicity but does not result in infection.

2. Those containing a modified toxin (a toxoid) that has lost its toxic properties but retain its immunogenicity.

3. Those containing live, attenuated organisms (i.e. genetic variants of a virus or bacterium) that are antigenically similar to the original strain but lack virulence.

Recombinant DNA research has allowed the production of new and more specific vaccines. For example, the gene for the B antigen of hepatitis virus has been cloned in E. coli, the protein expressed and a specific anti-B antiserum produced which can be used as a vaccine.

Vaccine
A preparation of killed microorganisms, living attenuated organisms, or living fully virulent organisms that is administered to produce or artificially increase immunity to a particular disease.

Vacuum Degasification
The process of removing dissolved and entrained gases from the Reverse Osmosis (RO) product water by creating a vacuum in a tower through which this water flows. The degasifier may be located before the RO system but the majority of the time will be located after. The most prevalent gas present is Carbon Dioxide (CO2), which may have been generated during pH adjustment of the RO feed water. The anion exchange resin can remove CO2 but using the vacuum degasifier can reduce that load. The other gas of concern is Oxygen, which can also be removed by a vacuum degasifier.

Validation
A documented program that provides a high degree of assurance that a specific process, method, or system will consistently produce a result meeting pre-determined acceptance criteria.

Validation Master Plan
The documented plan for qualification of a facility or part of a facility that identifies the layout of the operation, the associated utilities and systems, the equipment, and the processes to be validated. The validation master plan also provides preliminary information as to the extent of the qualification and validation (IQ, OQ, PQ), required documentation, SOPs, acceptance criteria and responsibilities. Validation Master Plans should also establish the cross reference of qualification projects by product, system, discipline, etc.

Validation Protocol
A written plan describing the process to be validated, including production equipment and how validation will be conducted. Such a plan would address objective test parameters, product and process characteristics, predetermined specifications, and factors, which will determine acceptable results.

Validation Protocol (from ICH API)
A written plan stating how validation will be conducted and defining acceptance criteria. For example, the protocol for a manufacturing process identifies processing equipment, critical process parameters/operating ranges, product characteristics, sampling, and test data to be collected, number of validation runs, and acceptable test results.

Vapor Pressure
Dalton's Law for a mixture of perfect gases states that the mixture pressure is equal to the sum of the partial pressures of the constituents. The partial pressure of moisture is called vapor pressure, and is expressed as: Total Pressure (Pt) = Partial Pressure of Air (Pa) + Partial Pressure of Moisture (Pv)

Vascular Targeting Agents (VTAs)
Multifunctional agents that are home to the capillaries and vessels of solid tumors.

Vector
An agent, such as an insect, that can carry a disease-producing organism from one host to another; the agent used to carry new genes into cells. Plasmids currently are the vectors of choice, though viruses and other bacteria may sometimes be used. These molecules become part of the cell protoplasm.

VEAs (Vasopermeation Enhancement Agents)
A new generation of drugs that increase the uptake of therapeutic agents to solid tumors.

Vegetative Form In bacteria, a stage of active growth, as opposed to a resting state or spore formation.

Vehicle
Any solvent or carrier fluid in a pharmaceutical product that has no pharmacological role. For example, water is the vehicle for xilocaine and propylene glycol is the vehicle for many antibiotics.

Verification
The act of reviewing, inspecting, testing, checking, auditing, or otherwise establishing and documenting whether items, processes, services, or documents conform to specified requirements. (also see: IQ (Installation Qualification))

Veterinary
Referring to pharmaceuticals or biologicals intended for animal use. Historically veterinary products were made by less than "Good Manufacturing Products". Today, however, the GMP's refer to both human and veterinary products.

Viable Living
Viable Organism Capable of living and reproducing. Thus, nothing is sterile as long as it contains even a single viable organism.

Vial
A final container for a parenteral or diagnostic product. Sealed with a rubber closure and over-seal. Generally required to be class I borosilicate glass.

Viral Antigens
Specific proteins on the capsid of a virus that can act as inducers of antibody formation.

Virion
A fully formed, mature virus. Infection is initiated in a cell by a virion.

Virucide
An agent that destroys or inactivates viruses.

Virulence
The disease-producing power of a microorganism.

Virus
A simple, noncellular parasite that can reproduce only inside living cells. The simple structure of viruses is their most important characteristic. Most of them consist only of a genetic material - either DNA or RNA - and a protein coating. Some also have membranous envelopes. Viruses are "alive" in that they can reproduce themselves - although only by taking over a cell's synthetic machinery - but they have none of the other characteristics of living organisms. Viruses cause a large variety of significant diseases in plants and animals, including humans.

Viscosity
The tendency of a fluid to resist flowing because of molecular attraction (cohesion).

Vitamin

Term coined in 1911 (vita, Latin word for life, and the chemical term amine) by polish biochemist, Casimir Funk, represents one of a group of organic substances, some of which are of unknown composition, present in minute amount in natural foodstuffs which are essential to normal metabolism. A lack of which in the dietary causes deficiency diseases. Vitamins are commonly classified into two groups, the fat-soluble, and the water-soluble. Vitamins A, D, E, and K are fat-soluble. Vitamin C and members of the vitamin B complex group are water-soluble. In general, the vitamins play catalytic and regulatory roles in the body's metabolism. Among the water-soluble vitamins, the B vitamins apparently function as coenzymes. Vitamin's C coenzyme role, if any, has not been established. Part of the importance of vitamin C to the body may result from its strong antioxidant action. The actions of the fat-soluble vitamins are less well understood. Some of them, too, may contribute to enzyme activity, and some of them are essential to the functioning of cellular membranes.

VPHP
Microbiodecontamination Technology used to decontaminate the exposed, internal surfaces within a sealed isolator and the exposed, external surfaces of materials and components placed within the sealed isolator. It consists of four distinctive phases: 1. Dehumidification - Lowers humidity and increases temperature 2. Conditioning - "Ramp-up" (VPHP) at or below saturation conditions 3. Sterilization - Steady-State (VPHP) at or below saturation conditions 4. Aeration - Reduces the VPHP to Safe Levels.

VTAs