Muscarinic receptors: 2-trimethylammonium-7-oxabicyclo[2.2.1]heptane iodide epoxides and 2-trimethylammoniumbicyclo[2.2.1]heptane iodides

✍ Scribed by Wendel L. Nelson; David R. Allen; Frank F. Vincenzi

• Publisher: John Wiley and Sons
• Year: 1972
• Tongue: English
• Weight: 318 KB
• Volume: 61
• Category: Article
• ISSN: 0022-3549
• DOI: 10.1002/jps.2600611023

✦ Synopsis

a Values are for individual samples.

During the test, one could observe particles of the disintegrated tablet forming a ring at the bottom of the fabricated flask (Fig. 3).

It is not likely that one would use the type of dissolution vessel shown in Fig. 2 when the other two types are commercially available.

There are, however, other commercially available resin pots or dissolution vessels and possible differences of the type illustrated could occur with these vessels. These could be important to a formulator or a quality control investigator working with other products and under varying conditions. Finally, the testing discussed here was done at 150 r.p.m., as called for in the USP XVIII monograph for hydrochlorothiazide tablets. The data presented in Table I11 appear to indicate that the magnitude of the difference between the various flasks is a function of the basket's rotational speed. This phenomenon will be dependent not only on the hydrodynamics in the bulk of the solution but, more importantly, in the concavity at the base of the flask where the granules tend to accumulate and lie relatively undisturbed.

Each product having a dissolution test in its USP XVIII or NF XI11 monograph should be investigated in this manner. Such studies are underway in these laboratories.

NOTES

Conclusions

These observations led to the following conclusions:

1. The shape of the dissolution flask, which is not clearly defined in USP XVIII and NF XIII, can significantly affect dissolution patterns (ostensibly by affecting hydrodynamics).

2. The magnitude of these differences is a function of the rotational speed of the USP basket.

3. Formulators should be aware that these differences exist, and it is recommended that there be more definitive specifications for the dissolution vessel in the compendia.