Drug analysis refers to the detection and analysis of ingredients and contents in drugs.
Drug analysis and testing involves the study of composition, physical and chemical properties, purity, and the determination of the content of active pharmaceutical ingredients and their preparations, to ensure that the medications are safe, rational, and effective.
rnDrug analysis and testing are very important for drug development, which generally encompasses disintegration test, dissolution test,
tablet hardness test, tablet fragility test, residual solvents test, dosage units uniformity test, bioavailability/bioequivalence detection, microbial limits test, particulate matter test,
elemental impurities analysis, and extractables & leachables test. To accomplish these analytical testing tasks, some drug analysis methods are employed. The most commonly used drug analysis methods are as follows:
rn1. Gravimetric analysisrnGravimetric analysis is the basic method of chemical analysis in drug analysis and testing. It refers to weighing a certain weight of the sample and using an appropriate method to separate the tested component from the other components in the sample and convert it into a certain weighing form and determine the content of the component. According to the different sample preparation methods, gravimetric analysis is usually divided into physical gravimetry, thermogravimetry, precipitative gravimetric analysis, and electrodeposition. The advantage of gravimetric analysis lies in the high accuracy of the analysis results.
rn2. Acid-base titrationrnThe acid-base titration method is widely used in the analysis and testing of pharmaceuticals. Many industrial products such as caustic soda, soda ash, ammonium sulfate and ammonium bicarbonate generally use acid-base titration to determine the content of their main components. In addition, acid-base titration is also commonly used in the analysis of raw materials, intermediate products and finished products in the food industry.
rn3. PH measurementrnThe pH indicator is an electronic potentiometer with high input impedance. The pH measurement method is included in the pharmacopeias of various countries. Unless otherwise specified, the pH value of the aqueous solution should be measured with an acidity meter that has a glass electrode as the indicator electrode and has a saturated calomel electrode as the reference electrode.
rn4. Spectroscopy technologyrnThe main principle of spectroscopy technology is that the drugs detected can be radiated through different frequencies. Vibration and rotation will occur when the frequency in a certain range is accepted by some substances. Through the recording of information such as wavelength, its spectrum will be obtained. Based on the spectrum, the actual structural form of the drug and the elements of the drug can be identified and analyzed, which has the advantages of faster detection speed, higher recognition, and high efficiency.
rn5. Chemiluminescence technologyrnIn drug analysis and detection, chemiluminescence is a relatively common technical method, which is mainly based on the principle that the concentration of the relevant detection substance in the chemical detection system and the chemiluminescence intensity of the system are linear and quantitative under specific conditions. The instrument detects the chemiluminescence intensity of the entire system, and the way to determine the actual content detected is a trace analysis method.
rn6. ChromatographyrnChromatography is a means of separation and analysis. The main chromatographic detection techniques include gas chromatography, liquid chromatography, and thin-layer chromatography. These techniques play an important role in the detection of food and drugs.rnThin-layer chromatography uses thin-layer analysis of solutions to ensure that it achieves the purpose of qualitative analysis and rapid separation of substances. This detection technology has high sensitivity and good efficiency in practice, and the entire detection test can be completed with a small amount of detection samples.
rn7. ElectrophoresisrnElectrophoresis is one of the important methods for biologics analysis. It has the advantages of high sensitivity, good reproducibility, and wide detection range. Electrophoresis means that a charged sample (protein, nucleotide, etc.) is placed in an inert support medium (such as paper, cellulose acetate, agarose gel, polyacrylamide gel, etc.) and with the effect of an electric field, would move to the corresponding electrode direction at their respective speeds, thus different components are separated into narrow zones. The last step is to use appropriate detection methods to record their electrophoretic maps or calculate their content.
rn8. DNA amplification methodrnThe DNA amplification technology belongs to the broader category of PCR technology, which can amplify the fragments of the DNA sample in the tube up to a million times, enabling the researchers to directly observe by naked eyes. DNA amplification technology is featured by sensitivity, specificity, convenience, and efficiency.
rnTo ensure the quality of medicines, analytical testing should be carried out in strict accordance with the quality standards of medicines before deciding whether medicines can be marketed and used.