Polymerase chain reaction; a process that exponentially amplifies (reproduces) a short piece of DNA having a specific nucleotide sequence, making possible
many research and clinical applications involving that DNA (used extensively in forensics). PCR may be qualitative or quantitative
Prescription Drug User Fee Act. An act passed in 1992 by the US Congress that mandated that pharmaceutical firms pay part of the costs associated with review
of license applications and inspections. Renewed in 1997 and 2002; in effect until Sept. 30, 2007
peak An individual component of a mixture that is washed out of the chromatography column during elution (the elution fraction).
The sharp rise in the line graph of a chromatogram that represents this phenomenon.
Polyethylene glycol, a polymer that usually consists of a size distribution of various molecular weight compounds. Physical and chemical properties
vary with the molecular weight (liquid to solid, viscosity, etc.). PEGs are used as surfactants in industry (for foods, cosmetics,
and pharmaceuticals); and in biomedicine as dispersing agents, solvents, ointment and suppository bases, vehicles, and excipients.
PEGylation Covalent attachment of polyethylene glycol molecule(s) to a protein molecule via selected amino acid side groups, for example
free amino or sulfhydryl groups. May be done to decrease toxicity or improve its solubility and circulating half-life in the
peptide bond The carbon–nitrogen covalent bond (link) between an amino group of one amino acid and a carboxyl group of another, formed
by removing water and resulting in the group RCO-NH. This linkage does not allow free rotation, and it is the important bond that connects amino acid monomers to form the polymer
known as a polypeptide.
peptide mapping Bioanalytical method in which proteins are selectively cleaved by enzymes to create a characteristic pattern of peptides that
is elucidated through chromatographic separations and spectroscopic or spectrometric detection.
peptides Proteins consisting of fewer than 40 amino acids.
perfusion Sometimes perfusion propagation; a cell culture or fermentation process commonly used in antibody production, in which high concentrations of mammalian cells
inside a chamber have fresh growth media continually circulated around them for continuous addition of nutrients and removal
of waste products.
permeate Also called filtrate, the part of a mixture that passes through a filter.
pH Power of hydrogen, or the log of the concentration of H+ ion in a solution. Measurement of the relative alkalinity or acidity of a solution. Pure water is pH neutral (7), acidic solutions have pH values
between 0 and 7, and alkaline or basic solutions have pH values between 7 and 14. Often a critical control parameter in biopharmaceutical
phage A virus-like parasite that infects bacteria; also bacteriophage.
pharmaceutical development Collected information from development studies conducted to establish that the dosage form, formulation, manu-facturing
process, and quality attributes are appropriate for the product. The development process should identify and describe the
critical quality attributes and critical process parameters that influence product quality and performance.
pharmacodynamics Study of the reactions between drugs and living structures, including the processes of bodily responses to pharmacological,
biochemical, physiological, and therapeutic effects. A PD study seeks to determine where a drug penetrates in the body and
by means of what mechanisms.
pharmacokinetics Study of the ADME processes for compounds and medicines.
Phenylalanine, one of over 20 naturally occurring amino acids.
phenotype The observable characteristic that results from the action of an organism's genes. Phenotype varies depending on which alleles
of each gene are present.