Lab Testing FAQ: HPLC, LC-MS, Potency & Pharmaceutical Testing

HPLC (high-performance liquid chromatography) testing pumps a dissolved sample through a packed column under high pressure so each compound separates and is measured by a detector. Comparing the result with a reference standard shows which compounds are present and how much of each. It is the standard method for potency and purity testing of drug products. Learn more on our HPLC testing lab page.

Pharmaceutical labs use HPLC to measure potency (how much active ingredient is present), confirm identity against a reference standard, and check purity by finding degradation products or impurities. It supports batch release, stability studies and verification of compounded preparations (NCBI StatPearls). Our compounding pharmacy potency testing service is built on these HPLC assays.

First the sample is weighed and dissolved, then filtered and injected into the instrument. A pump pushes it through the column, where compounds separate by how strongly they interact with the packing. A detector, usually UV, records each compound as a peak. Retention time helps identify it, and peak area compared with a reference standard gives the amount. See how HPLC testing works at our lab.

A single instrument run often takes minutes, but a full test takes longer because it includes sample preparation, system suitability checks, reference standards, data review and the written report. Turnaround depends on the product and whether a method already exists for it. We confirm timing with your quote; for current turnaround, call 936-379-5515 or email info@renewlabgroup.com.

HPLC pricing depends on the compound, the tests you need (potency, identity, purity), the number of samples and whether a method must be developed. Testing one active ingredient with an established method costs less than a new method or a multi-ingredient product. For a firm quote, call 936-379-5515 or email info@renewlabgroup.com, or see our HPLC testing lab page.

A validated HPLC method is highly accurate and repeatable for measuring an active ingredient against its label claim. Under ICH Q2(R2), methods are validated for accuracy, precision, specificity, linearity and range before results are reported (FDA / ICH Q2(R2)). Accuracy also depends on a good reference standard and proper sample handling. Read more in our article on HPLC vs LC-MS.

LC-MS (liquid chromatography-mass spectrometry) separates a sample by liquid chromatography and then identifies each compound by its mass-to-charge ratio. Labs use it to confirm a compound’s identity by molecular weight, identify unknown peaks, measure substances at trace levels and run confirmation tests in toxicology. See our LC-MS testing services for what we test.

Both start with liquid chromatography to separate the sample. HPLC usually measures each compound with a UV detector, which is ideal for potency against a label claim. LC-MS adds a mass spectrometer that weighs each molecule, so it can confirm identity and detect much smaller amounts. Our HPLC vs LC-MS guide compares them side by side.

Not for every question. LC-MS is more specific and more sensitive, so it is better for confirming identity, finding unknowns and trace analysis. For routine potency of a known active ingredient, a validated HPLC-UV method is accurate and more economical. We recommend the method that answers your question; see which test you need or LC-MS testing services.

LC-MS/MS, or tandem mass spectrometry, uses two mass analyzers in a row. The first selects an ion of the target compound, the ion is broken into fragments, and the second analyzer measures those fragments. The fragment pattern works like a fingerprint, so LC-MS/MS is highly selective and is widely used for confirmation testing. Learn more about our LC-MS and LC-MS/MS testing.

Yes. Renew Lab Group accepts products from individual consumers as well as pharmacies and businesses. We test what is in the product, for example whether the labeled ingredient is present and how much, using HPLC or LC-MS. Before sending anything, call 936-379-5515 or email info@renewlabgroup.com so we can confirm we can test it. See pharmaceutical product testing for individuals.

Contact us with the product name, labeled ingredient and strength, and dosage form. We confirm the method, sample amount, price and turnaround, then you drop the sample off at our lab at 6001 Central Crest, Houston, TX 77092 or ship it using our instructions. You receive a certificate of analysis. Pharmacies can read about potency testing for compounding pharmacies.

Product testing analyzes the product, not your body, so it is different from a clinical test. Requirements can vary by product, so call 936-379-5515 or email info@renewlabgroup.com before sending a sample and we’ll tell you exactly what we need. Individuals can start on our testing for individuals page.

Independent testing confirms that weighing, mixing and formulation produced the labeled strength, supports beyond-use dates and documents quality for prescribers and inspectors. An FDA survey of compounded products ordered online found that 34% failed at least one quality test, most often for low potency (FDA). See our compounding pharmacy potency testing service.

A certificate of analysis is the written report of a lab’s results for a specific sample or batch. Ours lists the sample ID, product and labeled strength, date received, test method, reference standard, the result for each test, and analyst and reviewer sign-off. For our own bacteriostatic and sterile water, a COA is run monthly and covers each production batch. Need help reading one? Call 936-379-5515. See what is on our COA.

Percent of label claim compares the amount of active ingredient measured with the amount the label states. A capsule labeled 10 mg that measures 9.5 mg is 95% of label claim. The acceptable range depends on the product and its specification, so a pharmacist or the product’s specification decides pass or fail. Learn more about potency testing.

Endotoxin testing detects endotoxins, fever-causing substances from the outer membrane of Gram-negative bacteria, in products such as sterile preparations and pharmaceutical water. The LAL test uses Limulus amebocyte lysate from horseshoe crab blood, which reacts with endotoxin, in gel-clot, turbidimetric or chromogenic formats (FDA). See our full lab testing services.

Microbiology testing checks a product for living microorganisms. It can include sterility testing for products that must be sterile, total aerobic microbial count and total yeast and mold count (TAMC/TYMC), bioburden and tests for specified organisms. Which tests apply depends on the product and its specification. Ask about microbiology on our HPLC lab testing services page.

ICP-MS (inductively coupled plasma mass spectrometry) measures metals and other elements at very low levels. In pharmaceuticals it is used to test elemental impurities such as lead, arsenic, cadmium and mercury, following the risk-based approach of ICH Q3D (FDA). Ask about ICP-MS on our lab testing services page.

TOC (total organic carbon) testing oxidizes the organic molecules in a water sample and measures the carbon released. USP describes TOC as an indirect measure of organic contamination in pharmaceutical water and a way to monitor a purification system; it does not replace endotoxin or microbial testing (USP 643). See pharmaceutical water testing.

Extractables are chemicals that can be pulled out of packaging or components under aggressive lab conditions, such as strong solvents or heat. Leachables are the chemicals that actually migrate into the product under normal storage. Testing both helps show that a container closure system is suitable for the product (FDA). Ask about extractables and leachables testing.

ISO 14644-1 classifies cleanrooms by how many airborne particles they allow. ISO 5 allows no more than 3,520 particles of 0.5 micrometers or larger per cubic meter of air, and ISO 7 allows up to 352,000 (ISO 14644-1). Critical work is done in ISO 5 zones inside cleaner surrounding rooms. Our facility includes ISO 5/ISO 7 cleanroom space; see lab services.

A toxicology test looks for drugs, medications and their metabolites in a specimen. A screening test shows whether a drug class may be present, and a confirmation test such as LC-MS/MS identifies the specific substance and how much is there (PubMed). We do not offer urinalysis or specimen pickup. See toxicology testing in Houston.

Both. Renew Lab Group works with consumers and businesses: individuals who want a product checked against its label, 503A compounding pharmacies, 503B outsourcing facilities, clinics and manufacturers. The process is the same for everyone: contact us, get a quote and a method, then submit your sample. Start with testing for individuals or testing for pharmacies.

Our lab, where samples are dropped off, is at 6001 Central Crest, Houston, TX 77092. Our corporate office is at 5847 San Felipe #2375, Houston, TX 77057. We serve customers in Houston and across the United States, and samples can also be shipped using the instructions we send with your quote. To plan a drop-off, call 936-379-5515 or email info@renewlabgroup.com. See our Houston HPLC lab.

Call 936-379-5515, email info@renewlabgroup.com or use our contact form. Tell us the product, labeled ingredient and strength, dosage form and what you need to know. We reply with the method, sample amount, price and turnaround. Then drop the sample off at our Houston lab or ship it as instructed.

No. Renew Lab Group does not offer urinalysis or a specimen courier or pickup service. Our toxicology work and product testing use samples delivered to our lab at 6001 Central Crest, Houston, TX 77092 or shipped according to the instructions in your quote. Call 936-379-5515 to confirm which sample types apply. Learn more about toxicology testing.

Yes. Your identity, samples and results are confidential and shared only with you unless you authorize otherwise. Pharmacies and businesses can ask about sending reports to additional contacts on their account. If you have questions about how we handle your information, call 936-379-5515 or email info@renewlabgroup.com. See how testing works for individuals.