Sonication for Drug Testing and Drug Potency Analysis
Ultrasonic homogenization and extraction is a common sample preparation technique before drug analysis, e.g. for quality tests, evaluation of raw materials and potency tests. Probe-type ultrasonicators are widely used for the release of active substances such as APIs, bioactive plant compounds and other substances.
Pre-Analytcial Sample Preparation in Drug Testing using Ultrasonication
Drug potency test are necessary to determine how much of an active compound is in a drug sample. Drug analysis and drug potency testing is used in the field of pharmacology, toxicology and forensics. Due to specificity and efficiency, high-performance liquid chromatography (HPLC) is the most commonly used methodology in drug potency analysis.
The key difference between assay and potency is that an assay is the testing of a material to determine its ingredients and quality whereas potency is the amount of a drug required to get an effect at its maximum intensity. Usage of these two terms, assay and potency, are common in biochemistry and pharmacology.
Ultrasonication is applied before potency analysis and assays in order to release bioactive ingredients or active pharmaceutical ingredients (APIs) from a matrix. Ultrasonication can extract target compounds from plant materials (e.g., leaves, roots etc.) or dissolve a pharmaceutical dosage form such as tablets in order to make the active ingredient available for subsequent analysis.
Step-by-step Protocol for Drug Analysis
Sample preparation is an important step in drug analysis and drug potency testing and involves several steps to ensure accurate and reproducible results. The following are the general steps involved in sample preparation before drug potency analysis:
- Sample Collection: The first step is to collect an appropriate sample of the drug product, which can be either in solid, liquid, or semisolid form. It is important to ensure that the sample is representative of the entire batch and is stored and handled properly to maintain its quality and stability.
- Sample Homogenization: The sample should be homogenized to ensure that the drug is evenly distributed throughout the sample. This step is critical for solid and semisolid samples. Ultrasonication is a highly efficient and reliable homogenization method and therefore commonly applied in sample preparation. Read more about the application of ultrasonic homogenizers for sample preparation!
- If the target substance is entrapped into a cellular matrix (e.g. plant material, cell tissue), the substance must be released before an analytic measurement or assay can be performed. Ultrasonic extraction is the superior technique to make entrapped substances available for collection and analysis. Read more about ultrasonic extraction of bioactive compounds!
- Sample Size Reduction: The next step is to reduce the sample volume to an appropriate amount for analysis. This can be achieved by weighing a portion of the sample or by using a sample divider.
- Sample Dilution: If the sample concentration is too high, it may need to be diluted to bring it within the linear range of the assay. The diluent used should be appropriate for the drug and the assay method being used.
- Sample Aliquoting: The diluted sample should be aliquoted into individual portions to ensure that the same amount of sample is used for each assay. This step helps to reduce variability between assays and improve reproducibility.
- Sample Storage: The aliquoted samples should be stored under appropriate conditions, such as refrigeration or freezer storage, to maintain their stability until they are ready to be analyzed.
These steps are general guidelines for sample preparation and may vary depending on the specific drug and assay method being used. It is important to follow the instructions provided by the assay manufacturer to ensure accurate and reliable results.
How promotes ultrasound the isolation of bioactive compounds from plant material?
Bioactive compounds such as terpenes, cannabinoids or flavonoids can be isolated from plants using an ultrasound-based process called ultrasonic extraction, which involves the treatment of a slurry consisting in the ground plant material in a solvent (e.g. alcohol, water, aqueous ethanol, hexane etc.) with high-power ultrasound. Applying intense ultrasonication to a liquid or slurry results in the generation of acoustic cavitation. The phenomenon of acoustic cavitation is characterized by locally occurring very energy-dense conditions of very high pressure and temperature differentials as well as liquid jets and shear forces. In this energy-dense field, cell walls are perforated and broken-up so that intracellular material is release into the surrounding solvent. After the sonication process, the target molecules are completely released from the cellular matrix and float in the solvent. Via isolation techniques such as evaporation or distillation, the target substance can be purified and further processed if necessary.
Ultrasonic extraction is used in the production of bioactive compounds (e.g., adaptogens, essential oils, cannabis- & terpene-rich products) for consumption as nutritional supplements, food additives and therapeutics as well as in the analysis of drugs.
Ultrasonic Lab Homogenizers for Sample Preparation before Drug Analysis
Hielscher Ultrasonics develops, manufactures and supplies high-performance ultrasonicators for homogenization and extraction. Hielscher ultrasonic homogenizers and extractors are used in the pharmaceutical industry and nutritional supplement manufacturing in production and quality assessment. Ultrasonic homogenizers are also used for sample preparation in drug testing including screening for illegal substances in drugs, counterfeited drugs and human samples.
With features such as precise amplitude regulation, automatic data protocolling and browser remote control, Hielscher ultrasonicators allow for a highly standardized sample preparation.
The table below gives you an indication of the approximate processing capacity of our ultrasonic systems from compact hand-held homogenizers and MultiSample Ultrasonicators to industrial ultrasonic processors for commercial applications:
|various vials and vessels
|multi-well/ microtiter plates
|10 vials à 0.5 to 1.5mL
|VialTweeter at UP200St
|0.01 to 250mL
|5 to 100mL/min
|0.01 to 500mL
|10 to 200mL/min
|10 to 1000mL
|20 to 200mL/min
|10 to 2000mL
|20 to 400mL/min
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Literature / References
- Dent M., Dragović-Uzelac V., Elez Garofulić I., Bosiljkov T., Ježek D., Brnčić M. (2015): Comparison of Conventional and Ultrasound Assisted Extraction Techniques on Mass Fraction of Phenolic Compounds from sage (Salvia officinalis L.). Chem. Biochem. Eng. Q. 29(3), 2015. 475–484.
- Fernandes, Luz; Santos, Hugo; Nunes-Miranda, J.; Lodeiro, Carlos; Capelo, Jose (2011): Ultrasonic Enhanced Applications in Proteomics Workflows: single probe versus multiprobe. Journal of Integrated OMICS 1, 2011.
- Priego-Capote, Feliciano; Castro, María (2004): Analytical uses of ultrasound – I. Sample preparation. TrAC Trends in Analytical Chemistry 23, 2004. 644-653.
- Welna, Maja; Szymczycha-Madeja, Anna; Pohl, Pawel (2011): Quality of the Trace Element Analysis: Sample Preparation Steps. In: Wide Spectra of Quality Control; InTechOpen 2011.