Liquid Formulations: Characteristics, Quality Requirements, Classification

1. Chapter 2 Introduction to Liquid Formulations

2. WHICH MOVIEs ARE THEY from?

3. 《Titanic》 《A Chinese Odyssey》 《Roman Holiday》 BARRIER

4. 《Titanic》 《A Chinese Odyssey》 《Roman Holiday》 PROPER DELIVERY Eye contact A big hug …… Words

5. LIQUID SOLID GASEOUS

6. IBUPROFEN: which formulation is for a small child? Suspension (liquid) Tablet (solid)

7. LIQUID FORMULATION 04 02 03 01 meaning characteristics quality requirements classification WHEN AND WHY TO CHOOSE LIQUID FORMULATION

8. §1 meaning • Liquid formulations • theliquid disperse system prepared by dispersing the APIinto an appropriate dispersion medium for internal or external use. Active Pharmaceutical Ingredient (API) Dispersion medium

9. §1 meaning • Liquid formulations • theliquid disperse system prepared by dispersing the APIinto an appropriate dispersion medium for internal or external use. Active Pharmaceutical Ingredient (API) “DISPERSE” Dispersion medium

10. §1 meaning Absorption barrier Small particles/ molecules

11. §1 meaning • Dissolution: • the transfer of molecules or ions from a solid state into solution Cs: saturation concentration

12. §1 meaning • What influences the rate of dissolution?

13. §1 meaning • The rate of dissolution: Noyes-Whitney equation dm/dt: The rate of mass transfer of solute molecules or ions through a static diffusion layer k1: diffusion coefficient A: area available for molecular or ionic migration Cs: saturation concentration h: the thickness of the boundary layer

14. §1 meaning Dissolution rate slow WHY? “DISPERSE” quick

15. §2 characteristics • Advantages: • High dispersity, fast absorption, quick action. • Elevated bioavailability of some solid drugs. • Lowered irritationby concentration control. • Convenient for dose division, and drug taking. • Extensive administration routes: internal, external, cavity

16. §2 characteristics Lowered irritation by concentration control Concentration↑ Irritation ↑

17. §2 characteristics • Disadvantages: • Stability • Physical: high dispersity→high surface free energy →phase separation • Chemical: short period of validity in dissolved state • Biological: susceptible to microorganism • Inconvenient for packaging, transportation and storage • Palatability

18. §3 quality requirements • Dispersity: • Homogeneous liquid preparations should be clear solution; • In heterogeneous liquid preparations, drug particles should be dispersed uniformly; • Accurate concentration • Compliance: • The oral liquid preparations should have good appearance and proper taste; • The external liquid preparations should be have no irritation • Antiseptic ability • Packaging: • Proper containers and convenient for patients to carry and use.

19. §4 classification • By disperse system: • Homogeneous • Low molecular solutions (molecular/ionic state, <1nm) • High molecular solutions (large molecules, >1nm) • Heterogeneous • Sols (1-100nm) • Emulsions (>100nm) • Suspensions (>500nm)

20. §4 classification • Classification by disperse system

21. §4 classification • By administration routes: • Internal: • mixtures, syrups, emulsions, suspensions… • External • Skin: lotions, liniments… • Five sense organs: ear drops, nasal drops, gargles… • Cavity (rectum, vagina, urethra)

22. Summary • Liquid formulations: • Meaning • Characteristics • Quality requirements • Classification

23. Key terms • Solution • solvent, solute, dissolve/dissolution • Solubility, saturated • Dissolution rate • Disperse, dispersion, dispersity

24. Questions • 1. What characteristics do liquid preparations have? • 2. When and why do we choose liquid formulation?