O slideshow foi denunciado.
Seu SlideShare está sendo baixado. ×

Pharmaceutical Suspensions and Emulsions

Carregando em…3

Confira estes a seguir

1 de 58 Anúncio

Mais Conteúdo rRelacionado

Diapositivos para si (20)

Quem viu também gostou (20)


Semelhante a Pharmaceutical Suspensions and Emulsions (20)


Mais recentes (20)

Pharmaceutical Suspensions and Emulsions

  1. 1. PRESENTED BY S.Deepak 11AB1R0050 UNDER THE ESTEEMED GUIDANCE OF Mrs.PALLAVI. K M.Pharm Vignan Pharmacy College 1 Assistant Professor. VIGNAN PHARMACY COLLEGE. Approved by PCI,AICTE, New Delhi. Affiliated to JNTU,Kakinada. Vadlamudi -522213, Guntur, A.P.
  2. 2.  These are biphasic liquid dosage forms in which the particle size of the dispersed phase ranges from 0.1mm.  These are mainly of 2 types Suspensions Emulsions Vignan Pharmacy College 2
  3. 3. Vignan Pharmacy College 3
  4. 4. Vignan Pharmacy College 4  Definition. Classification. Advantages & disadvantages Packing of suspensions Formulation of suspensions CONTENTS
  5. 5. Vignan Pharmacy College 5 Definition A Pharmaceutical suspension is a coarse dispersion in which internal phase (therapeutically active ingredient) is dispersed uniformly throughout the external phase.
  6. 6.  The internal phase consisting of insoluble solid particles having a range of size(0.5 to 5 microns) which is maintained uniformly through out the suspending vehicle with aid of single or combination of suspending agent.  The external phase (suspending medium) is generally aqueous in some instance, may be an organic or oily liquid for non oral use. Vignan Pharmacy College 6 Internal phase: External phase :
  7. 7. 1. Antacid oral suspensions 2. Antibacterial oral suspension 3. Dry powders for oral suspension (antibiotic) 4. Analgesic oral suspension 5. Anthelmentic oral suspension 6. Anticonvulsant oral suspension 7. Antifungal oral suspension Vignan Pharmacy College 7 SOME MARKETED SUSPENSIONSTYPES OF PHARMACEUTICAL SUSPENSIONS
  8. 8. Vignan Pharmacy College 8  Oral suspension eg: Paracetamol suspension antacids, Tetracycline HCl. Externally applied suspension eg :Calamine lotion. Parenteral suspension eg: Procaine penicillin G Insulin Zinc Suspension Classification Based On General Classes :
  9. 9. Vignan Pharmacy College 9 Based on Proportion of Solid Particles:  Dilute suspension :Concentration ranges from 2 to 10% w/v solid. Eg: cortisone acetate, predinisolone acetate  Concentrated suspension: Concentration ranges from 50%w/v solid Eg: zinc oxide suspension
  10. 10. Vignan Pharmacy College 10 Based on Size of Solid Particles : Colloidal suspensions: •Suspensions having particle sizes of suspended solid less than about 1micron in size are called as colloidal suspensions. Coarse suspensions: •Suspensions having particle sizes of greater than about 1micron in diameter are called as coarse suspensions. -
  11. 11. Vignan Pharmacy College 11  Suspensions are the biphasic colloidal dispersions of nanosized drug particles stabilized by surfactants. Size of the drug particles is less than 1mm. Nano suspensions (10 ng) Advantages  Suspension can improve chemical stability of certain drug. E.g. Procaine penicillin G. Drug in suspension exhibits higher rate of bioavailability than other dosage forms. Order of bioavailability : Solution > Suspension > Capsule > Compressed Tablet
  12. 12. Vignan Pharmacy College 12  Physical stability , sedimentation and compaction can causes problems.  It is bulky and sufficient care must be taken during handling and transport.  It is difficult to formulate.  Uniform and accurate dose can not be achieved unless suspension are packed in unit dosage form. Disadvantages
  13. 13. Vignan Pharmacy College 13 Sedimentation means settling of particle (or) floccules occur under gravitational force in liquid dosage form. Stokes equation : Sedimentation Where, d = Diameter of particle r = radius of particle vsed.= sedimentation velocity in cm / sec ρ s= density of disperse phase ρ o= density of disperse media g = acceleration due to gravity η o = viscosity of disperse medium in poise (ρs -ρ0 )g PROPERTIES OF SUSPENSIONS
  14. 14. Vignan Pharmacy College 14 Limitation Of Stoke’s Equation : Stoke's equation applies only to: Spherical particles in a very dilute suspension (0.5 to 2 gm per 100 ml)  Particles which freely settle without collision .  Particles with no physical or chemical attraction.
  15. 15. Vignan Pharmacy College 15 Sedimentation Parameters: 1.Sedimentation volume (F) or height (H) for flocculated suspensions: Sedimentation volume is a ratio of the ultimate volume of sediment (Vu) to the original volume of sediment (VO) before settling. F = Vu / VO Where, Vu = final or ultimate volume of sediment VO = original volume of suspension before settling
  16. 16. Vignan Pharmacy College 16 F has values ranging from less than one to greater than one. The system is in flocculated equilibrium and show no clear supernatant on standing. Sediment volume is greater than the original volume due to the network of flocs formed in the suspension. When F=1 then Vu =Vo When F >1 then Vu > V o
  17. 17. Vignan Pharmacy College 17 Sedimentation volume Fig : Suspensions quantified by sedimentation volume (f)
  18. 18. Vignan Pharmacy College 18 2.Degree of flocculation (β) It is the ratio of the sedimentation volume of the flocculated suspension ,F , to the sedimentation volume of the deflocculated suspension, F∞ The minimum value of ß is 1,when flocculated suspension sedimentation volume is equal to the sedimentation volume of deflocculated suspension. ß = F / Fo
  19. 19. Vignan Pharmacy College 19 3.Brownian movement :  If particle size is about 2 to 5mm,  When the size of the dispersed particle approach that of colloidal dimensions brownian movement sets in . Equation for Brownian movement
  20. 20. Deflocculated suspensions In this system solids as present as individual particles . they also exhibit aggregation but comparatively low than flocculated . Pleasant appearance because of uniform dispersion of particles . Particles exhibit repulsive forces Particles settle independently Flocculated suspensions In this system solids aggregate by forming chemical bridges . Un slightly sediment and supernatant layer is formed. Particles exhibit attractive forces They settle as flocs Vignan Pharmacy College 20
  21. 21. Rate of sedimentation is slow and size of particle is small. Particles exist as separate entities Bioavailability is relatively high Rate is high as flocs are collection of smaller particles. Particles form loose aggregates  Bioavailability is comparatively less Vignan Pharmacy College 21
  22. 22. Vignan Pharmacy College 22
  23. 23. Vignan Pharmacy College 23  The formulation of a suspension depends on whether the suspension is flocculated or deflocculated.  Three approaches are commonly involved 1. Use of structured vehicle 2. Use of controlled flocculation 3. Combination of both of the methods FORMULATION OF SUSPENSIONS
  24. 24. Vignan Pharmacy College 24 Flow chart of formulation of suspension
  25. 25. 26 . Wetting agents They are added to disperse solids in continuous liquid phase. Flocculating agents They are added to floc the drug particles Thickeners They are added to increase the viscosity of suspension. Buffers and pH adjusting agents They are added to stabilize the suspension to a desired pH range. Osmotic agents They are added to adjust osmotic pressure comparable to biological fluid. Coloring agents They are added to impart desired color to suspension and improve elegance. Preservatives They are added to prevent microbial growth. External liquid vehicle They are added to construct structure of the final suspension. INGREDIENTS FOR FORMULATION OF SUSPENSIONS
  26. 26. Vignan Pharmacy College 27 Following consideration are important for manufacturing pharmacist :  Selection of right material that go into the manufacture.  The step involved and their sequence in the manufacture.  Preservation and storage of the product. PREPARATION OF SUSPENSIONS
  27. 27. Vignan Pharmacy College 28 Step -1 • Grinding or levigating of insoluble material Step -2 • All soluble ingredients are dissolved in same portion of the vehicle and added to the smooth paste to step1 to get slurry. Step -3 • The slurry is transformed to a graduated cylinder, the mortar is rinsed with successive portion of the vehicle. Steps involved in formulation of suspensions
  28. 28. Vignan Pharmacy College 29 Step -4 • Decide whether solids are: • suspended in structured vehicle • flocculated • Flocculated and then suspended Step -5 • Make up the dispersion to the final volume by adding suitable suspending agent
  29. 29. 30 Pharmaceutical suspensions for oral use are generally packed in wide mouth container having adequate space above the liquid to ensure proper mixing. Parenteral suspensions are packed in either glass ampoules or vials. Packaging of Suspensions
  30. 30. Vignan Pharmacy College 31 EMULSIONS
  31. 31. Definition Classification Applications Theory of emulsification Formulation of emulsions Emulsification techniques Stability of emulsions Vignan Pharmacy College 32
  32. 32. An emulsion is a thermodynamically unstable system consisting of at least two immiscible liquid phases one of which is dispersed as globules in the other liquid phase stabilized by a third substance called emulsifying agent. Vignan Pharmacy College 33
  33. 33.  Simple emulsions (Macro emulsions) Oil-in-water (O/W) Water-in-oil (W/O)  Multiple emulsions Oil-in-water-in-oil (O/W/O) Water-in-oil-in-water (W/O/W)  Micro emulsions These are clear transparent solutions particle size ranges from 10-200nm. Vignan Pharmacy College 34
  34. 34. Water in oil type (W/O): An emulsion is referred as water in oil, if the dispersed phase is water and the continuous phase is oil. Ex: Butter ,salad dressings Oil in water type (O/W) : An emulsion is referred to as oil in water ,if the dispersed phase is oil and the continuous phase is aqueous base . Ex : Turpentine liniment and Vanishing cream Vignan Pharmacy College 35
  35. 35. Oral products :  It covers the unpleasant taste  Increases absorption rate Topical use :  Washable  Acceptable viscosity  Less greasy Vignan Pharmacy College 36
  36. 36. It depends on the use to which an emulsion is required. Selection based on HLB for an emulsion which may be o/w or w/o may be given as follows First method: To produce emulsions of o/w type emulsifiers in the HLB value range of 8-18 are tried and for w/o type HLB 3-16 are tried. Second method : Griffin evolved a series of required material to be emulsified . Vignan Pharmacy College 37
  37. 37. The amount of emulsifier to be added for an emulsion can be calculated with HLB values of emulsifiers using the following formula Vignan Pharmacy College 38
  38. 38. Substance HLB value for o/w type HLB value for w/o type Cotton seed oil 6-7 - Petrolatum 8 - Beeswax 9-11 5 Paraffin wax 10 4 Vignan Pharmacy College 39 Comparsion of HLB values of o/w and w/o types of various substances :
  39. 39. Droplets can be stabilized by three methods : i) By reducing interfacial tension ii)By preventing the coalescence of droplets. a. By formation of rigid interfacial film b. By forming electrical double layer Vignan Pharmacy College 40
  40. 40. Emulsifying agents or Surface active agents or hydrophilic colloids or finely divided solid particles are needed to decrease the interfacial tension Interfacial tension increases Interfacial Area increases compared to original liquid Liquid broken into fine particles Vignan Pharmacy College 41 B
  41. 41. Mono molecular Multimolecular Solid particle films Vignan Pharmacy College 42 Mono molecular Multi molecular Solid particle films
  42. 42. Vignan Pharmacy College 43 - - - - - - + + + + + - - - - - - - + + + + Electrical double layer at oil-water interface Emulsion made with sodium soap. Oil Water
  43. 43. It is done by two methods : Small scale method : i) Wet gum method & ii) Dry gum method Vignan Pharmacy College 44
  44. 44. Wet gum method Vignan Pharmacy College 45 Emulgent is placed in the mortar Water is added to the emulgent and is dispersed to form a mucilage Oil is added in small amounts with continuous titrations .
  45. 45. Vignan Pharmacy College 46 Emulgent is placed in the mortar Oil is added to the emulgent and is dispersed to form a mucilage Water is added at a time with rapid continuous titrations .
  46. 46. Physical instability i. Flocculation Ii. Creaming or sedimentation iii. Aggregation or coalescence iv. Phase inversion Vignan Pharmacy College 47
  47. 47. Flocculation : Re dispersible association of particle within an emulsion to form large aggregates. Precursor to the irreversible coalescence. Differs from coalescence mainly in that interfacial film and individual droplets remain intact. Influenced by the charges on the surface of the emulsified globules. Vignan Pharmacy College 49
  48. 48. Creaming : Creaming is either upward movement or downward movement of dispersed droplets of emulsion relative to the continuous phase ( due to the density difference between two phases). Rate of creaming can be calculated using Stoke’s law Vignan Pharmacy College 50
  49. 49. Aggregation : Dispersed particles come together but do not fuse. Coalescence : It is the process by which emulsified particles merge with each to form large particles. Breaking : It is the destroying of the film surrounding the particles. The major factor to prevent coalescence is increasing the mechanical strength of the interfacial film. Vignan Pharmacy College 51
  50. 50. Phase inversion: An emulsion is said to invert when it changes from an o/w to w/o or vice versa. It occurs due to : Addition of electrolyte Addition of CaCl2 into o/w emulsion by sodium soaps can be inverted to w/o. Vignan Pharmacy College 52
  51. 51. Microbial contamination may occur due to: Usage of impure raw materials Poor sanitation conditions Invasion by an opportunistic microorganisms. Contamination by the consumer during use of the product.. Precautions to prevent microbial growth Use of uncontaminated raw materials Careful cleaning of equipment with live stream . Addition of Preservative agent. Vignan Pharmacy College 53
  52. 52. Emulsions Suspensions These are biphasic liquid preparations containing two immiscible liquids one of which is dispersed as minute globules into the other These are biphasic liquid dosage form of medicament in which finely divided solid particles are dispersed in a liquid Globule size of the dispersed liquid is in the range of 0.25 to 25µm Particle size of suspended solid is in the range of 0.5 to 5 microns Emulsifying agent is required to make a stable emulsion Suspending agent is required to make a stable suspension Emulsions are of two types oil-in-water type and water-in-oil type Suspensions are of two types flocculated and deflocculated There are several tests to confirm type of emulsion There are no tests to confirm type of suspension During storage freezing should be avoided as it may lead to cracking During storage freezing should be avoided as it leads to aggregation 54 Differences between Emulsions and Suspensions
  53. 53. To date Emulsions and Suspension have been shown to produce distinct advantages like Controlled Drug release Increased Bioavailability Protection of Thermolabile drugs Reduced patient Variability Hence these formulations provide a broad scope in the present and future research. Vignan Pharmacy College 55
  54. 54. Vignan Pharmacy College 56  Physical pharmaceutics by Manavalramaswamy Page no. 323-366  Martin A. Fourth edition, “Coarse dispersion” Physical Pharmacy, Lippincott Williams and Wilkins, Philadelphia 2001, Page No. 479-481. REFERENCES
  55. 55. Vignan Pharmacy College 57 Text Book of Physical Pharamaceutics, Subramanyam C.V.S., Second edition, “Suspensions and emulsions’’ PageNo. 374-387.  Tutorial Pharmacy, Cooper & Gun, Sixth edition, “Dispersed system” Page No. 75-78, REFERENCES
  56. 56. I sincerely thank my guide K. Pallavi madam for her support I am very thankful to our respected Principal Dr. P. Srinivas Babu sir and also to the seminar committee Vignan Pharmacy College 58 ACKNOWLEDGEMENT
  57. 57. Vignan Pharmacy College 59