Active pharmaceutical identification testing

The aim of validation of an analytical procedure is to demonstrate that the method employed in any product testing, such as the identification, control of impurities, assay, dissolution, particle size, water content, or residual solvents, is validated in the most important characteristics. Identification tests, quantitative tests for impurities content, limit tests for control of impurities, and quantitative tests of the active moiety in samples of pharmaceutical product are the most common types of analytical procedures that validation addresses [1]. 

MDI products are subject to batch control and acceptance tests similar to those for other pharmaceutical dosage forms, that is, active drug identification, dose delivery, and dose uniformity. Additional special tests unique to inhalers, e.g., characterizing the particle size distribution of the delivered aerosol, are also applied. Typical tests are shown in Table 3. 

Analytical method validation has developed within the pharmaceutical industry over the years in order to produce an assurance of the capabilities of an analytical method. A recent text on validation of analytical techniques has been published by the international Conference on Harmonisation (ICH) [19]. This discusses the four most common analytical procedures (1) identification test, (2) quantitative measurements for content of impurities, (3) limit test for the control of impurities and (4) quantitative measurement of the active moiety in samples of drug substance or drug product or other selected components of the drug product. As in any analytical method, the characteristics of the assay are determined and used to provide quantitative data which demonstrate the analytical validation. The reported validation data for CE are identical to those produced by an LC or GC method [11] and are derived from the same parameters, i.e. peak time and response. Those validation parameters featured by the ICH (Table 1) are derived from the peak data generated by the method. Table 1 also indicates those aspects of a CE method (instrumentation and chemistry), peculiar to the technique, which can affect the peak data and highlights factors which can assist the user in demonstrating the validation parameters. 

IR spectroscopy is often the method of choice for chemical identification on specifications for release of an active pharmaceutical ingredient and is included in all the major pharmacopoeias. This method is simple, reliable and ensures correct chemical identification when compared with the spectrum of a suitable reference standard. However, the sample preparation required means that carrying out these tests can become time-consuming and there is little opportunity for automation in addition, poor sample preparation can lead to erroneous results. 

There are four major types of tests in the pharmaceutical industry. These are identification tests, quantitative tests for impurities content, limit for control of impurities, and quantitative tests of active moiety (11). A quantitative method, for example, an assay method, can be used as an identification method. In addition, many methods can be used for quantitative tests for both assay and impurities contents. 

At this meeting, a discussion about possible rework procedures may be appropriate. The ability to recover materials, especially expensive drug actives, is desirable. Early identification of steps where rework may be possible allows for procedures to be tested, verified, and put in place, should they be needed. For pharmaceuticals, rework procedures may be used only if they are appropriately documented, validated, and approved by the responsible corporate and government bodies. Rework procedures are not an automatic means for handling out-of-specification product lots but rather for identifying where an effort may be implemented successfully. Logistics and economics, as always, dictate whether a rework should be considered. 

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. ... 

Now days we talk about active constituents of phyto drugs. An active constituent is truly responsible for therapeutic activity of medicinal plant. The extracts are further subjected to chemical tests for identification of the plant constituents. The isolated constituents are of further importance to the pharmaceutical industry for applied research. A number of constituents like hyperforin, schizandrins, huperzine, andrographolide, andpicrrorhizin are being investigated for application in medical field. 

Pachaly, P. (ed) Simple Thin-layer Chromatographic Identification of Active Ingredients in Essential Drugs, Gesundheitshilfe Dritte Welt, German Pharma Health Fund e. V, ECV, Aulendorf 1994. Brochure for the identification and purity testing of pharmaceutical agents in the Third World. 

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