What’s a suspension ? Suspension Requirements? Why a suspension? Stability; HOW TO MAKE A FINE POWDER? (10-50 MICRON) Fluid Energy Preparing Flocculated suspensions Formulation considerations for orally administered suspension: Rheology Rheology for Pharmacists Excipients used in the formulation of suspensions for oral administration: Excipients used in the formulation of suspensions for oral administration: Some subdosage forms of suspensions Extemporaneous Prepration:

1. Pharmaceutical
Suspensions

2. What’s a suspension ?
• Defintion
• Dimentions(0.5-10) (1-10) (10-50)
• Good Suspension (10-50), Why?
• Both kinds:
o Oral Suspensions
o For Oral Suspension
Why called dry syrups?

3. What’s a suspension ?
• Dose
• 5 mL teaspoonful
• Dropper

4. Suspension Requirements
• Settling?
• How redispersed?
• Changes in The particle size?
• How pouring?

5. Why a suspension?
•Advantages
• Liquid Therapy!
• What about Chemical Stability?
• What about (infants, children, and the elderly) ?
• What about taste?

6. Why a suspension?
•Disadvantages
• What about stability and skills required?
• What about shelf-time?
• Appearapnce ?
• Carry with pateint?
• Note that:, erythromycin estolate

7. Stability;
• Is it perfect to repersent a Suspension?

8. Stability;
• So it’s an Indication
• Dicussing all factors affecting the stability, including:
• Particle size
• Density (floating vs. sedimentation)
• Viscosity
• Note that: It’s not appropriate to a
suspension to float??
• It’s not appropriate to have too
much fine powders??

9. HOW TO MAKE A FINE
POWDER? (10-50 MICRON)
• Micropulverization?---attrition mills
• Still finer powder? Fluid energy, what size?
• How?
• high-velocity compressed airstreams.
• confined space!

10. Fluid Energy
sonic and supersonic velocities of the airstreams

11. Preparing Flocculated
suspensions

12. Preparing Flocculated
suspensions

13. Preparing Flocculated
suspensions
• Definition
• less rigid or loose aggregation!!
• flocs settle more rapidly than fine ????
• weak particle-to-particle bonds
• higher sediment volume
• distribute readily

14. Preparing Flocculated
suspensions
• diluted bentonite magma.
flocculating agent
• pH: minimum solubility
• Electrolytes can also act as
flocculating agents
• The carefully determined
concentration of non-ionic and
ionic surface-active agents
(surfactants) can also induce
flocculation

15. Formulationconsiderationsfor orally
administeredsuspension:
• Physical properties of the therapeutic Agent:
• Particle size
• Crystallisation
• Hydrophilic polymers to solve the proplem.
• Particle Shape:
• i.e.: The needle-shaped particles formed a tenacious sediment cake on standing
that could not be redistributed, whereas the barrel-shaped particles did not cake
upon standing.

16. Formulationconsiderationsfor orally
administeredsuspension:
• Wetting properties of the therapeutic agent
• interfacial tensions should be decreased
• poorly wetted, will tend to aggregate

17. Rheology
• Imagine a suspension you cant pour it down!!!
• Imagine it fast to sedimentate.
• Let’s discover rheology by food!!

18. Rheology for Pharmacists Year 4

19. Rheology
• Newtonian Systems:

20. Rheology
• Newtonian Systems:

21. Rheology
• Pseudoplastic Systems:

22. Rheology
• Pseudoplastic Systems:
• i.e.: Veegum Magma (2%)

23. Rheology
• Pseudoplastic Systems:
• i.e.: Veegum Magma (2%)
• Thixotropy system

24. Rheology
• Dilitant flow Systems:

25. Rheology
• Dilitant flow Systems:
• i.e.: stratch gel.

26. Rheology
• Compare them:

27. And Now?
Are u still Ready?

28. Excipients used in the formulationof
suspensions for oral administration:
• Vehicle:
• Most common is
• It is prepared by distillation, ion exchange methods or by
reverse osmosis
• i.e.: Citric/Citrate of veicles:
• Acidity, Alkanity? Electrolytes? Taste?
• Our product. Citric/citrate which lead to pH=5.5
• Although it’s not the appropriate to minimum stability

29. Excipients used in the formulationof
suspensions for oral administration:

30. Excipients used in the formulationof
suspensions for oral administration:
Note that: a liquid suspension for a neonate should
not include preservatives, colorings, flavorings, or
alcohol because of the potential for each of these to
cause either acute or long-term adverse effects.

31. Excipients used in the formulationof
suspensions for oral administration:
• ExcipientstoenhancethephysicalstabilityofSuspensions:
• Addition of electrolytes
• (Brownian, Steric, and Electrostatic vs. Vandeer Vals)

32. Excipients used in the formulationof
suspensions for oral administration:

33. Excipients used in the formulationof
suspensions for oral administration:
• Surface-active agents:
• Effect on wetting

34. Excipients used in the formulationof
suspensions for oral administration:
• Effect on flocculation
• ionic or non-ionic polymers? And why?
• Consider oral preps and Safety.
•
e.g. polyoxyethylene fatty acid sorbitan esters, sorbitan esters or lecithin

36. Excipients used in the formulationof
suspensions for oral administration:
• Effectsonthephysicalstabilityofsuspensions:
stearic repulsion

37. Polymer Distance
•NoteThat:
• It reduces repulsion on far distance (stearic repulsion) but
enhance it on far distance (reduces zeta potential)
• Next example clarifies the idea.

38. Excipients used in the formulationof
suspensions for oral administration:
• Polymer Effect depends on the following:
• Concentration:
• enhances repulsion but does not prevent the interaction of the
particles in the secondary minimum

39. Excipients used in the formulationof
suspensions for oral administration:
• Polymer Effect depends on the following:
• The type of polymer:
• This ability to interact may effectively maintain the polymer-coated
particles at a distance, resulting in the production of a structured
floccule
stearic repulsion

40. Excipients used in the formulationof
suspensions for oral administration:
• Polymer Effect depends on the following:
• Effect on the rheological properties of oral suspension:
• concentrations ˃0.01%: (oral suspensions)
• Pseudoplatic system -thixotropy

41. Excipients used in the formulationof
suspensions for oral administration:
• Examples:
• MC, HEC, HPMC, sodium CMC
• Polyvinylpyrrolidone
• Acacia, tragacanth and xanthan (caution)
• Bentonite

42. Tired of presentation?
Let’s have a break!

43. Relaxed?
Let’s continue
with the
excipient

44. Excipients used in the formulationof
suspensions for oral administration:
• Preservatives and mold growth:
• Is the mold growth allowed?
• How much?
• What’s prevented?
• Examples

45. Excipients used in the formulationof
suspensions for oral administration:
• Sweetening agents/flavours
• Compliance?
• aesthetic properties?
• i.e.: sorbitol
• Antioxidants
• Stability?
■ i.e: sodium sulphite

46. Some subdosage forms of
suspensions
• DRY POWDERS FOR SUSPENSIONS:
• i.e.:Antibacterial , stability?
• Antacid Oral Suspensions
• RECTAL SUSPENSIONS.
• Antibacterial Oral Suspensions

47. Some subdosage forms of
suspensions
Sustained-Release Suspensions (Pennkinetic):

48. Some subdosage forms of
suspensions
Sustained-Release Suspensions (Pennkinetic):

49. ExtemporaneousPrepration:
Contact the supplier