Pharmaceutical Assays and Determination

Flashcards based on lecture notes for PCH 202: Inorganic Pharmaceutical Chemistry focusing on pharmaceutical assays, quality assurance, and error analysis.

What is the primary role of pharmacists according to Prof. Ajibola Olaniyi?

To serve as a source of therapeutic substances and provide information about their use and actions.

What responsibilities does a pharmacist have to assure drug quality?

Ensuring high quality in terms of chemical identity, purity, potency, stability, efficacy, safety, and acceptability.

How has the concept of drug quality evolved over time?

From simple checks of the final product to complex quality assurance systems spanning the whole manufacturing process.

Name some standard tests that ensure drug quality.

Identification, dissolution test, disintegration time, bioavailability, assay of active ingredients, stability, test for impurities, and toxicological data.

What is the Quality Assurance System (QAS)?

The creation and operation of standards, procedures, and management systems which guarantee the quality of drugs.

What does QAS involve in the pharmaceutical manufacturing process?

Monitoring the entire process from raw material acquisition to finished product, including checks, tests, and inspections at all levels.

What is the relationship between QA, QC, and GMP?

QA = QC + GMP, meaning quality assurance includes quality control and good manufacturing practice.

What is Quality Control (QC)?

A subset of QA that focuses on testing and verifying that a pharmaceutical product meets predefined specifications.

What are the key aspects of Quality Control?

Lab testing of drugs, ensuring drug potency, purity, and stability, identifying and rejecting defective batches.

What is Good Manufacturing Practice (GMP)?

Regulations and guidelines that ensure drugs are consistently produced and controlled according to quality standards.

What are the key aspects of GMP?

Covers facility design, equipment, personnel training, documentation, hygiene, contamination control, batch records, and process validation.

What is the purpose of QAS?

To ensure an absolute quality product with zero defects.

What are the '5Ms' that can be causes of poor quality products?

Men, Machines, Materials, Method, Milieu.

What is an assay?

An investigative procedure for qualitatively assessing and quantitatively measuring the presence, amount, or functional activity of a target entity.

Name the different types of assays.

Chemical assays, Biological assays (Bioassays), Microbiological assays, Immune assays, and Physical assays.

What are the three types of errors that can occur in the course of an analysis?

Gross errors, Systematic errors, and Random errors.

How are gross errors recognized?

They involve a major breakdown in the analytical process, such as samples being split or instruments breaking down.

What should be done if a gross error occurs?

The results are rejected and the analysis is repeated from the beginning.

What do precise and accurate measurements indicate in an assay?

The steps in the assay have been controlled very carefully.

What does a set of results with a mean less than the correct answer indicate?

The assay is precise but not completely accurate, indicating a systematic error.

What does a set of widely scattered assay results indicate?

The analysis contains random errors and was poorly controlled.

List some factors contributing to imprecision and inaccuracy in an assay.

Incorrect weighing, inefficient extraction, incorrect use of pipettes, improperly calibrated instrumentation, failure to use an analytical blank, degradation of the analyte, and interference by excipients.

What are the characteristics of a good assay method?

Sensitivity, specificity, repeatability, validity and stability.

What does specificity of a good assay method refer to?

Ability to assess unequivocally the analyte in the presence of components which may be expected to be present, including impurities and degradants.

What are the types of chemical assays?

Qualitative and quantitative assays.

Give examples of physicochemical assay techniques.

Photometry, Colorimetry, Spectrophotometry, Fluorimetry, and Chromatography.

What is the principle of flame photometry?

Matter absorbs light at the same wavelength at which it emits light.

What is the principle of colorimetry?

Colourless compounds are converted into coloured compounds using chemical reactions under defined reaction conditions in which the quantity of colour formed is proportional to the quantity of the original colourless compound.

What is the difference between colorimetry and spectrophotometry?

Colorimetry uses fixed wavelengths in the visible range, while spectrophotometry can use wavelengths in a wider range (UV and IR also).

What is the principle of fluorimetry?

Intensity of fluorescence is proportional to concentration.

What results in the differential separation of a compound using chromatography?

Differential affinities of the various components of the analyte towards the stationary and mobile phases.

Define the term 'analyte'.

Mixture whose individual components have to be separated and analysed

What determines the retention time in gas chromatography?

Time taken for a particular compound to travel through the column to the detector.

What are the two phases of high-performance liquid chromatography (HPLC)?

Normal phase and reverse phase.

What does an immunoassay use to generate measurable results?

Antibody and antigen complexes.

Give examples of immunossays.

Competitive immunoassays (e.g., inhibition ELISA) and Non-competitive immunoassays (e.g.,direct, indirect & sandwich ELISA)

What does a competitive enzyme-linked immunosorbent assay (ELISA) measure?

Unlabelled analyte in the test sample by its ability to compete with labelled antigen in the immunoassay.

What is the principle of microbiological assays?

Based upon a comparison of the inhibition of growth of microorganisms by measured concentration of the antibiotics to be examined with that produced by known concentrations of a standard preparation of the antibiotic having a known activity.

What is a bioassay?

Comparative assessment of relative potency of a test compound to a standard compound on a living or biological tissue.

Discuss the indication of Bioassay.

Can be needed if chemical method is not available, active principle can't be isolated, strength of a drug obtained from various sources due to different compositions,Biological activity of drug cannot be defined by a chemical assay etc

If a chemical assay is not available, too complex or insensitive to low doses what other assay should be used?

Bioassay should be considered

Define Physiological salt solutions.

Salt solutions useful for various tissue preparation with different use

What are examples of Physiological salt solutions with their use?

Frog-Ringer for Amphibian tissue preparation, Kreb’s for Mammalian/Avian skeletal muscle preparation, Tyrode for Intestine preparation etc

What are the main drawbacks of bioassay?

Biological variation, Troublesome, Time consuming, Expensive, Less accurate than physico-chemical methods

What is the formula for determining the percent mass of each atom in a compound?

(Mass of individual atom / Mass of whole molecule) * 100%

Identify the steps when determining the Purity of a substance using Elemental Analysis

Identify the major compound in the sample, Determine the chemical formula for the compound, Use the formula to determine the number of each type of atom present in the substance, Determine the mass of each type of atom by using atomic mass units provided in the periodic table etc.