A prediction system of oxidation reaction as a solid-state stress condition: applied to a pyrrole-containing pharmaceutical compound.

Stress conditions for predicting oxidative degradation products in solid-state pharmaceutical compounds were investigated. 4-Methyl-2-(3,4-dimethylphenyl)-1-(4-sulfamoylphenyl)pyrrole, Compound A, was used as the model compound for this study and its four main degradation products were due to oxidation, as identified by LC-MS and LC-(1)H NMR. In order to develop a prediction system for the oxidation reaction, solid-state Compound A was stored under moisture-saturated conditions. Hydrogen peroxide was added to the solution used to saturate the headspace with moisture and oxygen was substituted for the headspace air, in order to stimulate the oxidation reaction. After optimizing the conditions, a similar degradation product profile to that actually observed in the stability studies was obtained in only 3 days under conditions using 3% hydrogen peroxide at 40 degrees C. The prediction of the oxidative degradation products in a solid-state pharmaceutical compound was successfully achieved in a short term utilizing this newly developed prediction system.

Identification of degradation products in loxoprofen sodium adhesive tapes by liquid chromatography-mass spectrometry and dynamic pressurized liquid extraction-solid-phase extraction coupled to liquid chromatography-nuclear magnetic resonance spectroscopy.

Rapid and unambiguous identification of three degradation products (DP-1, DP-2 and DP-3) found in heat-stressed loxoprofen sodium adhesive tapes (Loxonin tapes) was achieved by LC-MS and dynamic pressurized liquid extraction (PLE)-solid-phase extraction (SPE) coupled to LC-NMR without complicated isolation or purification processes. The molecular formulae of the degradation products were determined by accurate mass measurements and product ion analyses and on-line hydrogen/deuterium (H/D) exchange experiments provided information about changes in the degradation of loxoprofen. To compensate for the low sensitivity of NMR, on-line dynamic PLE-SPE was employed and higher concentrations of degradation products trapped on the SPE column were afforded in a shorter time than they would be in such time-consuming sample preparations as pre-concentration after extraction. The loop-storage procedure was used in the LC-NMR analysis to allow the acquisition of the (1)H spectra of the three degradation products in one chromatographic run without affecting the peak separation and to avoid the carry-over of previously eluted DP-1 of high concentration by washing the NMR detection cell prior to the measurement of the DP-2 spectrum. Based on the resulting (1)H NMR spectra in combination with the MS results, DP-1 was successfully identified as an oxidation product having an oxodicarboxylic acid structure formed by the cleavage of the cyclopentanone ring of loxoprofen, DP-2 as a cyclopentanone ring-hydroxylated loxoprofen and DP-3 as a loxoprofen l-menthol ester.

Identification of a degradation product in stressed tablets of olmesartan medoxomil by the complementary use of HPLC hyphenated techniques.

An unknown degradation product (DP-1) increased in olmesartan medoxomil (OLM) tablets stored at 40 degrees C/75% r.h., reaching 0.72% after 6 months. The molecular weight and fragment information obtained by LC-MS suggested that DP-1 was a dehydrated dimer of olmesartan (OL) and the presence of ester carbonyl group was indicated by solvent-elimination LC-IR analysis. LC-(1)H NMR confirmed the structure of DP-1 as an esterified dimer of OL. Rapid and accurate identification of the degradation product was achieved by the complementary use of HPLC hyphenated techniques without complicated isolation or purification processes.

Application of liquid chromatography-two-dimensional nuclear magnetic resonance spectroscopy using pre-concentration column trapping and liquid chromatography-mass spectrometry for the identification of degradation products in stressed commercial amlodipine maleate tablets.

Application of the HPLC hyphenated techniques of LC-two-dimensional (2D) NMR using pre-concentration column trapping and LC-MS was demonstrated by the identification of two major degradation products, DP-1 and DP-2, in stressed commercial tablets of amlodipine maleate. The molecular formulas were estimated by LC-MS. Sample pre-concentration by column trapping was conducted to obtain adequate 2D-NMR signals by reducing the peak widths of the degradation products and making sure that the maximum amount of each component was inside the flow cell for NMR detection. Double-quantum filtered correlation spectroscopy (DQF-COSY) was applied to identify DP-1 as beta-N-lactosylamlodipine by suppressing the residual water signal without affecting the sample signal and by measuring the coupling constant of the lactose anomeric proton. Heteronuclear multiple bond coherence spectroscopy (HMBC) was applied to characterize DP-2 as an aspartic acid derivative of amlodipine by detecting long-range CH correlations. The chemical structures of the degradation products could be successfully elucidated unambiguously without an isolation process.

Verification of cefmetazole and cefpodoxime proxetil contamination to other pharmaceuticals by liquid chromatography-tandem mass spectrometry.

Cross-contamination is a critical issue for pharmaceutical manufacturing, especially for beta-lactam antibiotics. Thus, an analytical method for the simultaneous determination of beta-lactam antibiotics cefmetazole (CMZ) and cefpodoxime proxetil (CPDXPR) contaminants in non-beta-lactam pharmaceuticals was developed using high-performance liquid chromatography-tandem mass spectrometry. The developed method was found to be sensitive at the detection limit of 0.002 ppm for both compounds. Mean recoveries of CMZ and CPDXPR from olmesartan medoxomil (OLM) tablets were 96.7 to 102.2% and 88.9 to 94.2%, respectively. The developed method was successfully applied for the verification of CMZ and CPDXPR contamination to actually manufactured OLM tablets.

An approach for decontamination of beta-lactam antibiotic residues or contaminants in the pharmaceutical manufacturing environment.

An effective procedure for decontamination of beta-lactam antibiotic residues or contaminants in the pharmaceutical manufacturing environment was investigated. Decontamination with solutions of hydrochloric acid, sodium hydroxide, hydrogen peroxide and hydroxylamine as agents for degradation was assessed. According to the results, the beta-lactam antibiotics were significantly degraded with sodium hydroxide and hydroxylamine. From the structural analysis of the degradation products of a cephem antibiotic, cefpodoxime proxetil, it was found that hydroxylamine degraded the beta-lactam structure under mild conditions, while sodium hydroxide did not. Therefore, hydroxylamine was considered an appropriate decontamination agent for beta-lactam antibiotics.

Application of high-performance liquid chromatography hyphenated techniques for identification of degradation products of cefpodoxime proxetil.

Application of the HPLC hyphenated techniques of LC-MS, LC-NMR and solvent-elimination LC-IR was demonstrated by the identification of the degradation products of a third generation cephalosporin antibiotic, cefpodoxime proxetil, in solid state, drug formulation and solution. Molecular weight and fragment information were obtained by LC-MS, and detailed structural information was confirmed by LC-NMR. Information on the carboxyl functional group obtained by solvent-elimination LC-IR was useful for confirmation of the ester hydrolysis. The degradation products were successfully identified without complicated isolation or purification processes.

LC/MS/MS method for the determination of trace amounts of cefmetazole and cefpodoxime proxetil contaminants in pharmaceutical manufacturing environments.

In this study, a selective and sensitive LC/MS/MS method for the determination of trace amounts of cefmetazole (CMZ) and cefpodoxime proxetil (CPDXPR) contaminants in manufacturing environments was developed. The necessary sensitivity of this method was estimated based on the detection limit for Penicillin G required by the FDA and the total surface area and volume of the manufacturing facility. The detection limits of this method were estimated to be 10 pg/ml for CMZ and 5 pg/ml for CPDXPR from the signal to noise ratio and as a result satisfactory sensitivity was achieved. The method was linear in a concentration range from 0.20 to 3.20 ng/ml. The accuracy and precision were verified by the determination of the amount of CMZ and CPDXPR added to the sampling materials, a glass plate and a silica fiber filter. The mean recoveries of nine replicated determinations from the glass plate were 99.1% with 5.58%R.S.D. for CMZ and 97.1% with 3.80%R.S.D. for CPDXPR, and those from the silica fiber filter were 100.7% with 4.50%R.S.D. for CMZ and 95.4% with 2.85%R.S.D. for CPDXPR. This method has been successfully applied to the determination of CMZ and CPDXPR contaminants in samples collected from an actual manufacturing environment.

Determination of cefmetazole residue at pharmaceutical manufacturing facilities by chemiluminescence flow injection analysis.

Application of a sensitive and rapid flow injection analysis (FIA) method with luminol chemiluminescence detection for determination of trace amounts of cefmetazole (CMZ) in cephamycin antibiotic residue in pharmaceutical manufacturing facilities and on pharmaceutical manufacturing equipment has been investigated. The method was shown to be sensitive at a level of limit of detection of 0.06 ng/ml and for linear concentrations in the range of 0.3-1.5 ng/ml. Average recoveries of CMZ from stainless steel plates and glass plates were 62.1% and 60.1%, respectively, by adding 15 ng/100 cm2, and that of air sampling filters was 91.9% by adding 3 ng/filter. The proposed method has been successfully applied to the determination of CMZ residue in samples collected from an actual manufacturing facility and equipment. According to the results, no detectable CMZ residue was observed, therefore it was verified that no contamination had occurred to other pharmaceutical products manufactured in the facility.