Pharmaceutical Chemistry Flashcards
7 cards from real FPGEE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Pharmaceutical Chemistry flashcards as text
Which analytical technique provides definitive molecular weight determination for a pharmaceutical compound?
Answer: Mass spectrometry
Mass spectrometry measures the mass-to-charge ratio (m/z) of ions, providing precise molecular weight and fragmentation pattern information.
The chelation of metal ions by tetracycline antibiotics is clinically significant because:
Answer: It reduces absorption when taken with calcium, magnesium, or iron-containing products
Tetracyclines form insoluble chelate complexes with divalent and trivalent metal ions (Ca2+, Mg2+, Fe3+), significantly reducing oral absorption.
Polymorphism in pharmaceutical solids refers to:
Answer: The ability of a compound to exist in more than one crystalline form
Polymorphs are different crystalline arrangements of the same molecule, which can differ in melting point, solubility, dissolution rate, and bioavailability.
Which reaction is responsible for the yellow discoloration seen when phenothiazine drugs degrade?
Answer: Oxidation of the sulfur atom forming sulfoxides
Phenothiazines are oxidized at the sulfur atom to form sulfoxide metabolites and degradation products, producing characteristic colored compounds.
The Hammett sigma (σ) constant in quantitative structure-activity relationship (QSAR) studies describes:
Answer: Electronic effects (electron-donating or electron-withdrawing) of aromatic substituents
The Hammett σ constant quantifies the electronic effect of a substituent on an aromatic ring, with positive values indicating electron withdrawal and negative values indicating electron donation.
Which type of covalent bond formation between a drug and its target is associated with irreversible inhibition?
Answer: Alkylation of a nucleophilic residue
Covalent alkylation of nucleophilic residues (e.g., cysteine, serine) by reactive drug electrophiles creates a permanent drug-protein bond, irreversibly inhibiting the target.
In the context of drug stability, photolysis most commonly affects drugs containing:
Answer: Aromatic rings and conjugated double-bond systems
Drugs with aromatic rings and conjugated pi systems absorb UV/visible light, making them prone to photochemical degradation reactions.