Tablet testing identification

Metaprolol tartrate tablet testing uses UV and IR spectroscopy for metaprolol ID, TLC for the tartrate ion ID, and HPLC retention time for identification. The IR spectroscopy test is carried out by dissolving approximately 136 mg of finely ground tablets and in 25 mL of water with 4 mL of ammonium hydroxide (1 3). After extraction with chloroform, the organic layer is dried over anhydrous sodium sulfate, evaporated, and placed in a freezer to congeal... 

In the interest of patient safety, there exists a need for final identification testing of products as they are packaged for delivery to the patient. Herkert etal.lls evaluated a reflectance NIR instrument and found it to be capable of on-line identity check of tablets at-line speeds of 12 000 tablets a minute. 

Identification. Triturate a quantity of finely powdered tablets, containing the equivalent of about 100 mg of dipyridamole, with 10 mL of 0.1 N hydrochloric acid, and filter. Add 0.1 N sodium hydroxide to the filtrate until the solution is basic and a precipitate forms. Heat the mixture on a steam bath for 1 min, cool, filter, and dry the residue at 105°C for 1 h. The residue so obtained responds to the identification tests for dipyridamole. 

According to the Pharmacopoeia of the People s Republic of China [7], the method of identification testing of mefenamic acid in capsule and tablet preparations is based on light absorption spectrophotometry. A specific quantity of the powdered contents of capsules (or powdered tablets), equivalent to 0.25 g mefenamic acid, is dissolved in a mixture of 10 mL of 0.1 mL/L hydrochloric acid/methanol (1 99), shaken, and filtered. Then some quantity of the filtrate is diluted with the above-mixed solution to produce a solution having a concentration of about 20 pg/mL. The absorption spectrum of the solution exhibits maxima at 279 nm and 350 nm. 

This is the place to start, since most often, analytical chemists are trying to help solve someone else s problem. We need to define the solute and its matrix as well as the nature of the analytical problem. For example, in the world of pharmaceuticals, there are raw material identification and purity determinations, in-process testing, dosage-form determinations, content uniformity, dissolution testing, stability studies, bioavailability, pharmacokinetics, and drug metabolism, to name a few. Each of these analytical problems has its own specific requirements. The matrix can be a raw material, granulation, tablet, capsule, solution, lotion, cream, syrup, dissolution medium, blood serum, urine, or various body tissues and fluids. Similar definitions can be described for virtually any industrial area and problem set. These definitions will help select sample preparation, separation, and detection techniques. 

The cotton and rayon used as fillers in solid oral dosage form containers may not meet pharmacopeial standards, but through appropriate tests and acceptance criteria for identification and moisture content, their adequacy should be shown. For example, rayon has been found to be a potential source of dissolution problems for gelatin capsules and gelatin-coated tablets. 

In order to achieve this, a full physical description of the materials should first be carried out. It is sometimes possible, following this process, to feed the information obtained into relevant databases to identify the drug(s) present in the dose form. The identification process then becomes a simple matter of confirmation. If the dose form is not included in the databases, however, a full chemical analysis, including drug extraction from the tabletted material, presumptive testing, thin layer chromatography and a confirmatory technique must be undertaken. 

The application of NIR in the pharmaceutical industry can be qualitative or quantitative. Analytical samples can be liquid, solid, or vapor. Identification of a sample by fingerprint to compare with the reference standard is an example of a qualitative application. Materials such as active drug substances, organic liquids and solvents, excipients, and packaging materials can be tested rapidly for identity in the receiving area. Other applications encompass the identification of the film layer of coated tablets and the study of blending of active drug substances with excipients calculated by a chemometric technique with the use of computer software. ... 

For the tablet form of carbamazepine, an IR spectrum is obtained with a procedure slightly different from that for metaprolol. To carry out the test, 360 mg of powdered tablets is boiled in 15 mL of acetone, filtered, and evaporated to around 5 mL using a stream of nitrogen. Cooling in an ice bath gives rise to crystals, which after filtration and drying are used in a Nujol mull to obtain an IR spectrum. These procedures illustrate how the raw material and formulated product have different requirements for identification. The formu-... 

The near-IR spectral region has been used for chemical identification as well. Along with being used for analysis of polymorphic forms (43) and identification of raw materials and excipients (44,45), near-IR spectroscopy has also been used to test intact tablets (46). Aldridge et al. (47) have also demonstrated that active and placebo tablets can be identified by near-IR spectroscopy nonde-structively inside blister packs. 

The tests are carried out to pharmacopoeia standards (a pharmacopoeia is a technical text that contains tests for identification of products used in the pharmaceutical industry). For example, if we consider the previously mentioned products (chemical structures shown in Figure 11.1), they can be tested by HPLC-DAD under the European Pharmacopoeia (shortened to Ph Eur on packaging). Initially, the counterfeit products were identified by a wholesaler who noted a difference in the packaging by comparing results of bona fide tablets and the suspected counterfeit products, differences in the dose can be identified (see Figures 11.2 and 11.3). 

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