Tablet testing apparatus

All USP tablets must pass a test for disintegration, which is conducted in vitro using a testing apparatus. The detailed monograph for disintegration testing is described in the many pharmacopeias [2,3],... 

Generally, the force required to break a tablet may be expressed in either kilograms or pounds. It is of critical importance to note that because as results will vary with the specific make and type of the test apparatus used, direct comparison of results obtained on different types of apparatuses cannot be made. Thus, the same instrument must be used consistently throughout a particular study. 

A disintegration test with discs is performed for indapamide tablets. The apparatus is described in USP XXII under section [701] Disintegration (36). The test is accomplished by placing a tablet in each of the six tubes of the basket. The amount of time needed for the tablets to disintegrate completely in 0.1 N hydrochloric acid at 37°C is recorded. The disintegration test needs to be repeated for 12 additional tablets if one or two tablets fail to disintegrate completely. Of the 18 tablets, not less than 16 of the tablets must disintegrate completely. 

USP XXII requires that not less than 70 % of the labelled amount of prednisolone is dissolved in 30 minutes in dissolution medium water (900 ml) with paddle stirring element test apparatus (apparatus 2) at 50 rpm (119). In vitro dissolution profiles of sustainecj release formulations of prednisolone are given. For each tablet formulation 20 tablets were placed in a 100 ml beaker of 5.5 cm diameter 35 ml of distilled water were added and the contents were stirred for one hour, at 37°C. Sustained-release formulation gives a more uniform blood level of prednisolone and avoids high peaks of plasma prednisolone (120). 

Figure 4.50. Cumulative dissolution results. Two experimental tablet formulations were tested against each other in a dissolution test in which tablets are immersed in a stirred aqueous medium (number of tablets, constructional details and operation of apparatus, and amount of medium are givens). Eighty or more percent of the drug in either formulation is set free within 10 minutes. The slow terminal release displayed by formulation B could point towards an unwanted drug/excipient interaction. The vertical bars indicate ymean - with Sy 3%. A simple linear/exponential model was used to approximate the data for the strength 2 formulation. Strengths I and 3 are not depicted but look very similar.

The USP disintegration test is typical of most and is described in detail in a monograph of that volume. Briefly, it consists of an apparatus in which a tablet can be introduced into each of six cylindrical tubes, the lower end of which is covered by a 0.025 in.2 wire mesh. The tubes are then raised and lowered through a distance of 5.3-5.7 cm at a rate of29-32 strokes per minute in a test fluid maintained at 37 2°C. Continuous agitation of the tablets is ensured by this stroking mechanism and by the presence of a specially designed plastic disk, which is free to move up and down in the tubes. 

In the disc method, the powder is compressed by a punch in a die to produce a compacted disc, or tablet. The disc, with one face exposed, is then rotated at a constant speed without wobble in the dissolution medium. For this purpose the disc may be placed in a holder, such as the Wood et al. [Ill] apparatus, or may be left in the die [112]. The dissolution rate, dmldt, is determined as in a batch method, while the wetted surface area is simply the area of the disc exposed to the dissolution medium. The powder x-ray diffraction patterns of the solid after compaction and of the residual solid after dissolution should be compared with that of the original powder to test for possible phase changes during compaction or dissolution. Such phase changes would include polymorphism, solvate formation, or crystallization of an amorphous solid [113],... 

Disintegration official in Brit Pharmacon and USP PMA Tablet Committee proposes 1% solubility threshold USP and NF Joint Panel on Physiological Availability chooses dissolution as a test chooses an apparatus Initial 12 monograph standards official Variables assessment more laboratories, three Collaborative Studies by PMA and Acad. Pharm. Sci First calibrator tablets pressed First Case default proposed to USP... 

Over the years, dissolution testing has expanded beyond ordinary tablets and capsules—first to extended-release and delayed-release (enteric-coated) articles, then to transder-mals, multivitamin and minerals products, and to Class Monographs for non-prescription drug combinations. (Note at the time, sustained-release products were being tested, unofficially, in the NF Rotating Bottle apparatus). 

In < 711 >, there is a paragraph titled the Apparatus Suitability test. In this paragraph, the use of the USP calibrator tablets (Fig. 1) is required. There is some debate as whether... 

Schauble T. A comparison of various sampling methods for tablet release tests using the stirrer method [USP apparatus 1 2], Dissolution Technol 1996 3(2) 11-15. 

Solid oral dosage forms containing new chemical entities (NCEs) are commonly formulated into tablets or capsules as their first market image formulation. Subsequent drug product line extension development on these NCEs may evaluate more specialized drug delivery systems. Dissolution testing of standard oral tablets or capsules will commonly utilize the paddle or basket apparatus. In this chapter we focus primarily on the development and subsequent validation of dissolution testing methods that use these two devices. 

Dissolution testing should be carried out in USP Apparams 1 at 100 rpm or Apparatus 11 at 50 rpm using 900 ml of the following dissolution media (1) 0.1 N HCl or Simulated Gastric Fluid USP without enzymes (2) a pH 4.5 buffer and (3) a pH 6.8 buffer or Simulated Intestinal Fluid USP without enzymes. For capsules and tablets with gelatin coating. Simulated Gastric and Intestinal Fluids USP (with enzymes) can be used. 

The dissolution method for pentazocine hydrochloride tablets utilizes a UV determination of pentazocine in filtered test samples at 278 nm. The apparatus used is USP number two at 50 rpm with water as the dissolution medium. The solutions are measured in hydrochloric acid diluted with dissolution medium to give 0.01 N HC1 and quantitatively compared to a suitable standard (46). 

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