Dissolution apparatus

USP DISSOLUTION APPARATUS

1. DISSOLUTION APPARATUS PREPARED BY: PANKAJ 27/MPH/18 MPH 2 nd sem. DEPARTMENT OF PHARMACEUTICS

2. What is Dissolution Apparatus ? Tablet Dissolution is a standardized method for measuring the rate of drug release from a dosage form. In the pharmaceutical industry, drug dissolution testing is routinely used to provide critical in vitro drug release information for both quality control purposes, i.e., to assess batch-to-batch consistency of solid oral dosage forms such as tablets, and drug development, i.e., to predict in vivo drug release profiles.

3. Purposes of Dissolution Apparatus Test: Quality-control and quality-assurance purposes In early phase drug development Assess product stability, monitor formulation changes over time Establish in-vitro–in-vivo correlations "IVIVC" Regulatory perspective Particularly in the development and approval of generic dosage forms

4. Different types of dissolution apparatus according to the pharmacopeia: I.P U.S.P B.P E.P TYPE 1 Paddle Apparatus Basket Apparatus Basket Apparatus Paddle Apparatus TYPE 2 Basket Apparatus Paddle Apparatus Paddle Apparatus Basket Apparatus TYPE 3 Reciprocating Apparatus Flow through Cell Apparatus Flow through Cell Apparatus TYPE 4 Flow through Cell Apparatus TYPE 5 Paddle over disc Apparatus TYPE 6 Rotating cylinder TYPE 7 Reciprocating Holder

5. USP Dissolution Apparatus:   USP Apparatus 1: Basket type a) Vessel :-Made up of borosilicate glass -Semi hemispherical bottom -Capacity 1000ml b) Shaft :-Stainless steel 316 -Rotates smoothly without significance wobble 9 c) Basket :- Stainless steel 316 -Gold coatings up to 0.0001 inch. d) Water bath : Maintained at 37±0.5⁰c. Used for : Capsules, tablets, delayed release, suppositories, floating dosage forms. 

6. The rotating basket apparatus consists of a cylindrical basket held by a motor shaft. The basket holds the sample and rotates in a round flask containing the dissolution medium. The entire flask is immersed in a constant-temperature bath set at 37°C. The rotating speed and the position of the basket must meet specific requirements set forth in the current USP. The most common rotating speed for the basket method is 100 rpm. CONTD….

7. USP APPARATUS 2: PADDLE TYPE 1. Vessel 2. Shaft : The blade passes through shaft so that bottom of blade fuses with bottom of shaft. 3. Stirring elements : Made of Teflon For laboratory purpose - Stainless steel. 4. Water-bath : Maintain at 37±0.5⁰c. 5. Sinkers : Platinum wire used to prevent capsule /tablet from floating.    Used For : Capsules, Powders, Suspensions, Tablets (preferred over Apparatus 1) SINKERS

8. The paddle apparatus consists of a special, coated paddle that minimizes turbulence due to stirring. The paddle is attached vertically to a variable-speed motor that rotates at a controlled speed. The tablet or capsule is placed into the round-bottom dissolution flask, which minimizes turbulence of the dissolution medium. The apparatus is housed in a constant-temperature water hall maintained at 37ºC, similar to the rotating-basket method. The position and alignment of the paddle are specified in the USP. The paddle method is very sensitive to tilting. Improper alignment may drastically affect the dissolution results with some drug products. The most common operating speed for Apparatus II are 50 rpm for solid oral dosage forms and 25 rpm for suspensions. Apparatus II is generally preferred for tablets. A sinker, such as a few turns of platinum wire, used to prevent a capsule or tablet from floating.  CONTD...

9. USP Apparatus 3: Reciprocating cylinder 1 . Vessel :Cylindrical flat bottom glass vessel. 2. Agitation type : Reciprocating -Generally 5-35 rpm. 3. Volume of dissolution fluids :200-250 ml. 4. Water bath : Maintain at 37±0.5⁰c. Use for : Extended release tablets

10. The USP Apparatus III is considered as the first line apparatus in product development of controlled-release preparations, because of its usefulness and convenience in exposing products to mechanical as well as a variety of physicochemical conditions which may influence the release of products in the GI tract. The particular advantage of this apparatus is the technically easy and problem free use of test solutions with different pH values for each time interval. It also avoids cone formation for disintegrating (immediate release) products, which can be encountered with the USP apparatus II. An additional advantage of apparatus III includes the feasibility of drug-release testing of chewable tablets. Chewable tablets for human use do not contain disintegrants , so they need to undergo physiological grinding (i.e., chewing) prior to dissolution. For example , enteric-coated/sustained release dosage forms, and also offers the advantages of mimicking the changes in physiochemical conditions and extraordinarily strong mechanical forces experienced by the drug products in the mouth or at certain locations in the GI tract, such as the pylorus and the ileocecal valve. CONTD….

11. USP Apparatus Type 4: Flow Through Cell Design: Reservoir : For Dissolution Medium Pump : Forces Dissolution medium through the cell, holding the sample. Flow rate 240-960 ml/hr Laminar flow is maintained. Water bath : Maintain at 37±0.5ºC. Used for : Tablets, capsules, or granules.

12. Types : Closed-mode : where the fluid is re-circulated and, by necessity, is of fixed volume. Open-mode : when there is continuous replenishment of the fluids. Advantages: Ease of maintaining sink condition during dissolution which is often required for drugs having limited aqueous solubility. Feasibility of using large volume of dissolution fluid . Feasibility of automation of apparatus. CONTD..

13. USP APPARATUS TYPE 5: PADDLE OVER DISC Vessel Shaft Stirring elements Sample holder : Disk assembly that hold the product in such a way that release surface is parallel with paddle. Paddle is directly attached over disk assembly. Samples are drawn away b/w the surface of medium and top of paddle blade. Volume : 900ml. Temperature : 32 ⁰c. 23 Used for : Evaluation of Transdermal products

14. USP APPARATUS TYPE 6: CYLINDER APPARATUS Vessel: In place of basket cylinder is used. Cylinder: Stainless steel 316. Sample: Mounted to cuprophan (inner porous cellulosic material) an entire system is adhere to cylinder. -Dosage unit is place in cylinder and released from outside. water-bath: Maintain at 32±0.5⁰c Used for : Transdermal patches can be studied but cannot be cut into small size. 24

15. USP APPARATUS TYPE 7: RECIPROCATING DISC The sample are placed on disc shaped holder using inert porous cellulosic support which reciprocates vertically by means of a drive inside a glass container containing dissolution medium. Vessel : Flat bottom cylindrical vessel -Volume of dissolution medium 50-200ml. Shaft Sample : Placed on disk shaped holders. Agitation : Reciprocation -Reciprocating frequency 30 cycles/min. Water-bath : Maintain at 32±0.5⁰c. Used for : Transdermal patches and non-disintegrating controlled-release oral preparations.

16. REFERENCES: Aulton’s Pharmaceutics The Design And Manufacture of Medicines 3RD Edition page No: 17-22. https://en.wikipedia.org/wiki/Dissolution_testing International Journal of Current Biomedical and Pharmaceutical Research, Current Sci -Direct Publication USP 30 and NF 25. US Pharmacopeial Convention. 2007; Rockville, MD.