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Dissolution study of solids and suspension.ppt

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Dissolution study of solids and suspension.ppt

1. 1. A Presentation OnDissolution study of solids and suspension By Mr. Ghodake Chaitanya A. Under the Supervision of Mr. N. A. Guajrathi Assistant Professor P.S.G.V.P.M’s DEPARMENT OF PHARMACEUTICS SHAHADA, DISTRICT- NANDURBAR MAHARASHTRA. 2011-2012
2. 2. CONTENTS• Introduction• Theories of Drug Dissolution• Dissolution of Solids • Dissolution of Powder • Dissolution of Capsules • Dissolution of Tablets• Dissolution of Suspension• Dissolution of Suppositories• References 2
3. 3. Definition-• Dissolution is a process in which a solid substance solubilizes in a given solvent i.e. mass transfer from the solid surface to the liquid phase.• Rate of dissolution is the amount of drug substance that goes in solution per unit time under standardized conditions of liquid/solid interface, temperature and solvent composition. 3
4. 4. Theories of Drug DissolutionI. Diffusion layer model/Film TheoryII. Danckwert’s model/Penetration or surface renewal TheoryIII. Interfacial barrier model/Double barrier or Limited solvation theory. 4
5. 5. I. Diffusion layer model/Film Theory :- Noyes whitney equation 5 dc/dt = k (Cs- Cb)
6. 6. II. Danckwert’s model/Penetration or surface renewal Theory :- 6
7. 7. III. Interfacial barrier model/Double barrier or Limited solvation theory :- According to the interfacial barrier model, an intermediate concentration can exist at the interface as a result of solvation mechanism and is function of solubility. When considering dissolution of crystal, each face of the crystal will have the different interfacial barrier. The concept of this theory is explained by following equation- G = Ki (Cs - Cb) Where, G = dissolution rate per unit area, Ki = effective interfacial transport constant. 7
8. 8. Dissolution of solidsIn the dissolution of solids, we have1.Powders2.Tablets3.Capsules 8
9. 9. Dissolution of PowdersWettability and Dissolution Rate of PowdersThe first step in the process of dissolution is wetting of the dissolving surface,which is in contact with the dissolution medium.The condition for complete wetting of a solid surface is that the contact angleshould be Zero.This condition is fulfilled only when the forces of attraction between theliquid and solid are equal to or greater than those between liquid and liquid. 9
10. 10. Dissolution of Capsules Dissolution ofDrug in capsule Drug in capsule mass Capsule shell Drug particle in Suspension Drug in solution Name of the APPARATUS dosage Capsule II (Paddle) Drug in blood Capsule I (Basket) Capsule II (Paddle) (Extended Release) 10
11. 11. Dissolution of tabletTablet Disintegration Granules Deaggregation drug particles in suspension Non - Disintegration Drug in the solution in GI fluid Drug in blood Name of the APPARATUS dosage Tablet II (Paddle) Tablet I (Basket) 11
12. 12. Dissolution of Sustained Release formulationThe dissolution of sustained or controlled release formulation is done by in vivoin vitro methods. The USP dissolution testing apparatus are used for in vitrotesting of sustained action formulation , which includes the rotating bottle Stationary basket/ rotating filter Sartious absortion and solubility simulator Colum-type Flow through assemblyThe time of testing may vary from 6 to 12 hours, depending upon specificationof dosage form 12
13. 13. Dissolution of suspensionThe dissolution of suspension is similar to the post disintegrated form oftablet and capsule.Several studies have shown that the absorption of several poorly solubledrug administered in suspension formulation is dissolution rate limited.The apparatus used in dissolution studies are as followsUSP apparatus II (Paddle) Rotation speed is between 25 to 100 RPMRotating Filter apparatus Developed by Shah with the Basket removed temp 37°+- 2°c RPM 25 to 100 Dissolution medium 900- 1000 ml 13
14. 14. Dissolution of suppositoriesThe in vitro Dissolution testing for suppositories has always pose adifficult problem. Early testing was carried out by simple placement in abeaker containing medium.Dissolution apparatus which are used for dissolution study ofsuppositories 1. Apparatus I (Paddle apparatus with disk) 2. Apparatus II (Basket apparatus) 14
15. 15. Acceptance criteriaAcceptance criteria as per Indian Pharmacopoeia for various dosage form  Conventional-release dosage forms Level Number Acceptance criteria tested S1 6 Each unit is not less than D* + 5 percent**. S2 6 Average of 12 units (S1 +S2) is equal to or greater than D, and no unit is less than D –15 per cent**. S3 12 Average of 24 units (S1+S2+S3)is equal to or greater than D, not More than 2 units are less than D – 15 per cent** and no unit is less than D – 25 per cent**. *D is the amount of dissolved active ingredient specified in the individual Monograph, expressed as a percentage of the labelled content. **Percentages of the labelled content. 15
16. 16. Prolonged-release dosage formsLevel Number Acceptance criteria testedL1 6 No individual value lies outside each of the stated ranges and no individual value is less than the stated amount at the final test time.L2 6 The average value of the 12 units (L1 + L2) lies within each of the stated ranges and is not less than the stated amount at the final test time; none is more than 10 per cent of labelled content outside each of the stated ranges; and none is more than 10 per cent of labelled amount below the stated amount at the final test time. 16
17. 17. L3 12 The average value of the 24 units (L1 + L2 + L3) lies within each of the stated ranges, and is not less than the stated amount at the final test time; not more than 2 of the 24 units are more than 10 per cent of labelled content outside each of the stated ranges; not more than 2 of the 24 units are more than 10 per cent of labelled content below the stated amount at the final test time; and none of the units is more than 20 per cent of labelled content outside each of the stated ranges or more than 20 per cent of labelled content below the stated amount at the final test time 17
18. 18. Acceptance criteria as per USPStage Number tested Acceptance criteriaS1 6 Each unit is not less than Q +5%S2 6 Average of 12 units (S1+S2) is equal to or greater than Q, and no unit is ;ess than Q – 15%S3 12 Average of 24 units (S1+S2+S3) is equal to or greater than Q, not more than 2units are less than Q- 15%, and no units are less than Q-25% Q is the amount of dissolved active ingredient specified in the individual Monograph, expressed as a percentage of the labelled content. 18
19. 19. REFERENCE•IP 2007•USP 2005•Industrial pharmacy BY LacchmannLiebermann•Umesh v. banakar ,pharmaceuticaldissolution testing, volume 47,marceldekkar, inc., new york,410-450.•Brahmankar D.M., Jaiswal,Biopharmaceutics and pharmacokinetics,1997, Vallabh prakashan, Delhi,290-292.•www.dissolutiontech.com•www.usp.org 19
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