Ibuprofen

Application Notes: Ibuprofen is the most commonly used analgesic. It is a vasoconstrictor and fever reducer. According to the USP methods, ibuprofen contains no less than 97% and no more than 103% ibuprofen based on a dried basis. The USP HPLC method for the separation of procainamide was developed on Legacy L1 column according to the US Pharmacopeia methodology. L1 classification is assigned to reversed-phase HPLC column containing Ci18 ligand. Support for the material is spherical silica gel with particles size 3-10 um and pore size of 100-120A. Resolution between critical pairs corresponds to rules and specifications of USP.

Application Columns: Legacy L1 C18 HPLC column

Application compounds: Ibuprofen and benzophenone

Mobile phase: .01M H3PO4/MeCN (55/45)

Detection technique: UV

Reference: USP35: NF30

Mixed-mode columns allow to quantitate drugs and their counter-ions in one run. Hydrophobic acidic drug and hydrophilic inorganic counter-ions are separated and quantified on an Obelisc R HPLC trimodal column. This column can be used to quantify hydrophilic basic and hydrophilic acidic drugs, hydrophobic basic and hydrophobic acidic drugs, and corresponding organic and inorganic counter-ions. Various detection techniques can be applied to obtain reliable and robust method. Mixed-mode chromatography allows to retain ionizable compounds without ion-pairing reagent. This HPLC method can be adopted as universal and robust approach for analysis basic and acidic drugs and their counter-ions. Method is compatible with various detection techniques – ELSD, UV, CAD, and LC/MS.

Prednisolone, atrolactic acid, and ibuprofen were separated in one HPLC run on an Obelisc R HPLC column. Obelisc R columns have C12 carbon chain and basic and acidic groups on the surface of silica gel. Compounds are separated by combination of reversed-phase, cation-exchange, and anion-exchange mechanisms. Obelisc R column can be used for retention and separation of acidic and basic hydrophilic compounds, acidic and basic hydrophobic compounds, and neutral compounds. Elution is monitored by common detection techniques like UV, ELSD, CAD and LC/MS.

Motrin is cough and cold composition manufactured by McNeil PPC. It contains ibuprofen as non-steroidal anti-inflammatory drug (N-SAID) and pseudoephedrine as decongestant. Ibuprofen is hydrophobic acidic molecule and pseudoephedrine hydrophilic molecule. Pseudoephedrine does not retained well in reversed phase chromatography and requires the use of ion-pairing reagent. In the absence of ion-pairing reagent pseudoephedrine comes close to the void of the column even at low concentrations of acetonitrile, while ibuprofen shows strong retention by reversed-phase mechanism. Different properties of these two molecules require gradient elution and consequent equilibration of the column. In contrast when mixed-mode HPLC column, like Primesep 100, is used, the method can be isocratic, very short with no equilibration of the column. Ibuprofen is retained by strong reversed-phase mechanism and pseudoephedrine is retained by weak reversed-phase and strong cation-exchange mechanisms on Primesep 100 column. Retention time of hydrophobic molecule is controlled by amount of acetonitrile, and retention of hydrophilic basic molecule is controlled by the amount of buffer and buffer pH. Method can be UV, ELSD and LC/MS compatible with various additives to the mobile phase (TFA, ammonium formate or acetate, sulphate or phosphate buffers at various pH). This mixed-mode column can be used for analysis of other OTC drugs including mixtures of basic, acidic and hydrophobic compounds.

Ibuprofen lysine is ibuprofen based medication which is uses lysine as counter-ion of the ibuprofen. The use of lysine makes the drug more soluble in water. Lysine is very hydrophilic compound with low UV activity, while ibuprofen is hydrophobic compound with good UV activity. These properties are making straight analysis of Ibuprofen Lysine (ibuprofen lysinate) a challenging task. Ion-pairing reagent required for retention of lysine in reversed-phase chromatography. Both compounds can be quantitated in one run without use of IP reagent. Because of the huge difference in UV activity of ibuprofen and lysine, a separate method for quantitation of lysine in ibuprofen lysinate might be required. Separation involving switching valve and guard column allows to trap ibuprofen on the guard and wash it away during analysis of lysine. This HPLC method allows to quantitate lysine separately from ibuprofen. Detailed set up of switching valve/guard system is described in our newsletter. Method can be adapted to quantitation of single compound in complex mixtures.

Ibuprofen is in a group of drugs called non-steroidal anti-inflammatory drugs (NSAIDs). Ibuprofen works by reducing hormones that cause inflammation and pain in the body.
Pseudoephedrine is a decongestant that shrinks blood vessels in the nasal passages. Dilated blood vessels can cause nasal congestion (stuffy nose).
The combination of chlorpheniramine, ibuprofen, and pseudoephedrine is used to treat sneezing, itching, watery eyes, runny nose, stuffy nose, sinus congestion, cough, and pain or fever caused by the common cold or flu in common over-the-counter medication (Advil, NyQuil, Tylenol, etc.)
Active ingredients of Advil Allergy and Sinus composition are separated by combination of reverse phase, cation-exchange and anion exchange mechanisms. Obelisc R mixed-mode column is used to separate pseudoephedrine (polar basic compound), chlorpheniramine (hydrophobic basic compound), ibuprofen (hydrophobic acidic compound) and maleic acid (counter-ion, hydrophilic acid compound). Method can be used for QC in production, impurity profiling and research and development. All compounds are well separated with high efficiency and good peak shape. Method uses ammonium formate buffer but other buffers can be used as well (ammonium acetate, sodium and ammonium phosphate) with corresponding detection technique – ELSD, LC/MS, and UV. Chlorpheniramine is an antihistamine that reduces the natural chemical histamine in the body. Histamine can produce symptoms of sneezing, itching, watery eyes, and runny nose.

Gemfibrozil is used to lower cholesterol and triglyceride levels in the blood and Ibuprofen is a common over-the-counter painkiller. Fast separations of these two compounds are obtained on short 50 mm columns. Both Primesep B2 and Primesep D separate by a combination of anion exchange and reversed phase. Retention times on Primesep B2 can be adjusted by changing the percentage of acetonitrile. On Primesep D retention times can be changed by adjusting the percentage of acetonitrile and acetic acid in the mobile phase. The HPLC separations use a mobile phase of water, acetonitrile (MeCN, ACN), ammonium formate and acetic acid (HOAc) with UV detection at 270 nm.