特刊:具有抗病毒或抗菌作用的聚合物,聚合物混合物和聚合物药物释放系统-第二版

Body:Improving a drug's stability in the gastrointestinal (GI) tract is paramount for enhancing its bioavailability and therapeutic effectiveness. Various strategies are employed to protect the drug from the harsh gastric milieu and to ensure its release and absorption at the desired site within the GI tract.Polymer coatings are one such method used to shield drugs from the stomach's acidic environment. By preventing premature drug release, these coatings improve the bioavailability of unstable...

Synergism is a useful mechanism where combining two or more drugs is more effective than each constituent used alone. Such combinations are also called supra-additive interactions. The drugs collectively enhance the final therapeutic effect by acting on different targets. Another advantage is that the low dose of each constituent drug is sufficient to achieve the desired effect. This helps reduce the duration of therapy and lower the adverse effects of these drugs.
Such synergistic combinations...

Body:After oral administration, poor permeability often limits the rate at which drugs are absorbed through the intestinal epithelium. Enhancing drug permeability is crucial for effective therapy, and several strategies have been developed to overcome this challenge.One effective strategy involves the use of lipid-based formulations. These formulations enhance dissolution and solubility, targeting physiological mechanisms to increase drug absorption. This includes stimulating bile salt...

Polymorphism refers to the existence of a drug substance in multiple crystalline forms, known as polymorphs. Recently, this term has been expanded to include solvates (forms containing a solvent), amorphous forms (non-crystalline forms), and desolvated solvates (forms from which the solvent has been removed).
Some polymorphic crystals possess lower aqueous solubility than their amorphous counterparts, leading to incomplete absorption. For instance, the oral suspension of Chloramphenicol, which...

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,...

Rational drug product design integrates knowledge of the drug’s physicochemical properties, formulation components, manufacturing techniques, and intended route of administration. Each factor influences the drug’s performance, including how it is released, absorbed, and eliminated in the body.The physicochemical properties of a drug—such as solubility, stability, and particle size—affect its compatibility with excipients and the choice of dosage form. Excipients, though...