Generally speaking, the several necessary stages of new drug development are: 1) pre-formulation research; 2) dosage form selection, which is to determine the appropriate dosage form according to the physical and chemical properties of the drug, clinical treatment and application needs; 3) prescription research, That is, according to the physical and chemical properties of the API and the characteristics of the dosage form, appropriate excipients are selected; 4) Process research: According to the characteristics of the dosage form, combined with the physical and chemical properties and stability, the research of different processes is carried out, and the dissolution is initially used as the screening criterion; 5) The dosage form, After the prescription and process are determined one by one, we must start to consider the choice of packaging materials, pay attention to the inspection of the compatibility of the packaging materials; 6) The final basic work is quality research and stability research.
Pre-formulation research of preparations is an important prerequisite for a good start of a project. It provides an important basis for the selection of dosage forms, prescription technology and quality control, and is the basis for the development of safe, effective and stable pharmaceutical preparations. Preformulation studies refer to a series of research work on the properties of drugs before determining the dosage form and prescription. The research object: API; the research content: the physical and chemical properties of API. The specific pre-prescription research content includes:
- Physical properties of the drug: melting point, solubility, partition coefficient, dissociation constant, crystal form, etc.;
- The chemical properties of the drug: API chemical structure, stability, compatibility of raw materials and excipients with common preparations and excipients, etc.
- The biological properties of the drug: dosage, pharmacokinetics, relationship between pharmacodynamics and pharmacokinetic parameters, gastrointestinal absorption, etc.;
- The processing properties of the drug: crystallinity, compressibility, fluidity, particle size, density, shape, moisture absorption, etc.;
- Key raw material attributes closely related to the formulation