[Prescription references: preventing incompatibilities and instabilities]

Generic intravenous (IV) drugs are considered bioequivalent to their branded counterparts due to their 100% bioavailability upon administration. However, variations in stability among different drug products can significantly influence their therapeutic performance, even if they are pharmaceutically equivalent.Cefuroxime, a prophylactic antimicrobial, is often used as a single-dose IV injection for patients undergoing coronary artery bypass grafting surgery. A 3 g dose typically provides...

Drug interactions occur when the pharmacological effect of one drug is altered by another substance, either enhancing or diminishing its activity. The drug whose activity is altered is known as the object drug, and the substance causing the alteration is called the agent drug or the precipitant. The net effects of these interactions are mostly undesirable, leading to decreased effectiveness or increased adverse effects. In rare cases, interactions can be beneficial, such as the enhanced...

Changes in polymorphic forms can significantly influence the bioavailability of poorly soluble drugs. Although the FDA defines pharmaceutical equivalence based on having the same active ingredient, dosage form, and route of administration, it does not automatically disqualify products with different polymorphic forms. This means two products with different polymorphs can still be deemed pharmaceutically equivalent. However, polymorphic differences can affect properties like wettability,...

Orally administered drugs primarily enter the systemic circulation via passive diffusion through the intestinal membranes. The drug's absorption is influenced by drug stability in the gastrointestinal GI tract, membrane permeability, the surface area available for absorption, luminal drug concentration, and residence time in the lumen. Drug permeability can be enhanced by adjusting the lipophilicity, polarity, or molecular size of the drug, promoting its passive transport across intestinal...

The long-term stability of drug products is critical to ensuring their quality, safety, and effectiveness over time. Stability directly influences a product's ability to maintain its intended characteristics, ensuring it performs as expected during its intended shelf life. Key attributes such as drug potency, impurities, dissolution, and other physicochemical measures of performance are tested to assess stability. These parameters indicate how well the product retains its quality over time and...

Pharmaceutical products contain more than just the active drug; they also contain various excipients such as binders, solubilizers, stabilizers, preservatives, and other elements. In some cases, impurities or contaminants might be present. Traditionally, quality control in pharmaceuticals has primarily focused on the analysis of the active drug, often overlooking the impact of these additional components. The recent issue with heparin contamination by over-sulfated chondroitin sulfate, a...