Dissolution study of solids and suspension.ppt
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The document presents information on dissolution studies of solids and suspensions, including an introduction to dissolution theories, factors affecting dissolution of different dosage forms like powders, capsules, tablets, and suspensions, as well as acceptance criteria for dissolution testing as per Indian Pharmacopoeia and USP. Dissolution is defined as the process by which a solid substance solubilizes in a given solvent, and various apparatus and methods used to test dissolution of different dosage forms are discussed.
Dissolution study of solids and suspension.ppt
- 1. A Presentation On Dissolution 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. 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. 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. Theories of Drug Dissolution I. Diffusion layer model/Film Theory II. Danckwert’s model/Penetration or surface renewal Theory III. Interfacial barrier model/Double barrier or Limited solvation theory. 4
- 5. I. Diffusion layer model/Film Theory :- Noyes whitney equation 5 dc/dt = k (Cs- Cb)
- 6. II. Danckwert’s model/Penetration or surface renewal Theory :- 6
- 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. Dissolution of solids In the dissolution of solids, we have 1.Powders 2.Tablets 3.Capsules 8
- 9. Dissolution of Powders Wettability and Dissolution Rate of Powders The 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 angle should be Zero. This condition is fulfilled only when the forces of attraction between the liquid and solid are equal to or greater than those between liquid and liquid. 9
- 10. Dissolution of Capsules Dissolution of Drug 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. Dissolution of tablet Tablet 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. Dissolution of Sustained Release formulation The dissolution of sustained or controlled release formulation is done by in vivo in vitro methods. The USP dissolution testing apparatus are used for in vitro testing of sustained action formulation , which includes the rotating bottle Stationary basket/ rotating filter Sartious absortion and solubility simulator Colum-type Flow through assembly The time of testing may vary from 6 to 12 hours, depending upon specification of dosage form 12
- 13. Dissolution of suspension The dissolution of suspension is similar to the post disintegrated form of tablet and capsule. Several studies have shown that the absorption of several poorly soluble drug administered in suspension formulation is dissolution rate limited. The apparatus used in dissolution studies are as follows USP apparatus II (Paddle) Rotation speed is between 25 to 100 RPM Rotating Filter apparatus Developed by Shah with the Basket removed temp 37°+- 2°c RPM 25 to 100 Dissolution medium 900- 1000 ml 13
- 14. Dissolution of suppositories The in vitro Dissolution testing for suppositories has always pose a difficult problem. Early testing was carried out by simple placement in a beaker containing medium. Dissolution apparatus which are used for dissolution study of suppositories 1. Apparatus I (Paddle apparatus with disk) 2. Apparatus II (Basket apparatus) 14
- 15. Acceptance criteria Acceptance 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. Prolonged-release dosage forms Level Number Acceptance criteria tested L1 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. 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. Acceptance criteria as per USP Stage Number tested Acceptance criteria S1 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. REFERENCE •IP 2007 •USP 2005 •Industrial pharmacy BY Lacchmann Liebermann •Umesh v. banakar ,pharmaceutical dissolution testing, volume 47,marcel dekkar, 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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