Advances in rapid drug detection technology.

Spurious/Falsely-labeled/Falsified/Counterfeit (SFFC)drugs have become a major threat to public health, especially in rural areas of developing countries.The goal of this review is to provide an overview of rapid detection technologies for counterfeits recently reported, such as Near Infrared Spectroscopy, Near Infrared Chemical Imaging, Raman Spectroscopy, X-Ray Fluorescence, X-RayPowder Diffraction, Ion Mobility Spectrometry, Ion MobilityMass Spectrometry,Isotope Ratio Mass Spectrometry and visual analytical methods The advantages of each of these detection methods are introduced. Examples of characterization of SFFC drugs using the detection technology mentioned are presented. In addition, new characteristics and trends of SFFC drugs are listed and the solution is discussed.

Analysis of impurities in vertilmicin sulfate by liquid chromatography ion-trap mass spectrometry.

The characterization of impurities present in vertilmicin by liquid chromatography (LC) coupled with mass spectrometry (MS) is described. A reversed phase (RP)-LC method using a C18 column resistant to basic pH with an alkaline (pH 11) aqueous mobile phase was developed and coupled to MS with an electrospray ionization (ESI) source in the positive ion mode which provides MS(n) capability. In total, 18 impurities were detected in a commercial sample. Eleven impurities described in this work were newly identified.

Impurity profiling of micronomicin sulfate injection by liquid chromatography-ion trap mass spectrometry.

The characterization of impurities present in micronomicin sulfate injection by liquid chromatography (LC) coupled with mass spectrometry (MS) is described. A reversed phase (RP)-LC method using a C18 column resistant to an alkaline (pH 11) aqueous mobile phase was developed and coupled to MS with an electrospray ionization (ESI) source in the positive ion mode which provides MS(n) capability. A total of thirty six impurities were detected in commercial samples: five impurities were identified by comparison of their fragmentation patterns with those of available related substances, eleven of them were identified in accordance with relevant literature, while the other twenty impurities were newly identified using the MS/MS spectra of the available related reference substances as interpretative templates combined with knowledge of the nature of functional group fragmentation behaviors. This work was applied to evaluate the quality of micronomicin sulfate injection from different manufacturers.

Impurity profiling of etimicin sulfate by liquid chromatography ion-trap mass spectrometry.

A reversed phase (RP)-LC method using a C(18) column resistant to basic pH and an alkaline (pH 10) aqueous mobile phase was developed and coupled to MS with an electrospray ionization (ESI) source in the positive ion mode which provides MS(n) capability. In total, 26 impurities were detected in a commercial sample. The structures of the impurities were proposed based on comparison of their fragmentation patterns with those of the available reference substances, the synthetic route and literature data. Starting material and its residual impurities, intermediates, synthetic by-products and degradation products were the main sources of those impurities. 14 impurities described in this work were newly identified.

Screening adulteration of polypropylene bottles with postconsumer recycled plastics for oral drug package by near-infrared spectroscopy.

Adulteration of pharmaceutical packaging containers with postconsumer recycled plastic materials was considerably difficult to identify due to the similar chemical compositions of virgin and recycled plastics. In the present study, near-infrared (NIR) spectroscopy coupled with conformity test was proposed to screen the adulteration of pharmaceutical packaging containers. Two kinds of representative screening models were investigated on polypropylene (PP) bottles for oral drug package. The reliability of the screening models was validated through studying the identification reliability, specificity, and robustness of the methods. The minimum spiking level of two modeled adulterants at the proportion of 20% could be detected, and the unqualified sample from a domestic manufacturer was rejected by this developed method. This strategy represents a rapid and promising analytical method for screening the adulteration of pharmaceutical plastic packaging containers with postconsumer recycled plastics.

Impurity profiling of acetylspiramycin by liquid chromatography-ion trap mass spectrometry.

Investigation of acetylspiramycin (ASPM) and its related substances was carried out using a reversed-phase liquid chromatography/tandem mass spectrometry method. The identification of impurities in the ASPM complex was performed with a quadrupole ion trap mass spectrometer, with an electrospray ionization (ESI) source in the positive ion mode which provides MS(n) capability. A total of 83 compounds were characterized in commercial samples, among which 31 impurities that had never been reported and 31 partially characterized impurities were deduced using the collision-induced dissociation (CID) spectra of major ASPM components as templates. Most of the major impurities arise from the starting materials and the synthesis process. This work provides very useful information for quality control of ASPM and evaluation of its synthesis process.

Establishment of an HPLC identification system for detection of counterfeit steroidal drugs.

A set of simple HPLC methods employing UV detection were developed for detection of counterfeit drugs by the qualitative and quantitative analysis of nine steroidal drugs, ethinylestradiol, diethylstilbestrol, norethisterone, norgestrel, methyltestosterone, medroxyprogesterone acetate, progesterone, testosterone propionate and nilestriol. The methods were based on studies of the relationships between the retention factors (k) of the nine compounds and the percentages of water to methanol in the mobile phases on a reverse phase Alltima C(18) column giving reliable separation of the compounds under three sets of chromatographic conditions. The methods were validated using statistical tests and were used on nine commercial samples for detection of possible counterfeit drugs.

[Study on integrons in Escherichia coli which producing extended-spectrum beta-lactamases, isolated from stool specimen of chicken].

OBJECTIVE: To analysis the dissemination of integrons in the extended-spectrum beta-lactamases (ESBLs) producing Escherichia coli, isolated from stool specimen of chicken and to study the relations between the resistance and the integrons of these isolates. METHODS: The Escherichia coli isolates were collected from Gansu, Hubei, Sichuan provinces and Beijing municipal city, and were isolated from stool specimen of chickens. Using WHONET software, the Escherichia coli producing ESBLs were selected, and then detected by PCR method class 1, 2, 3, 4 integrase. PCR products of the variable region of the integron were sequenced. RESULTS: 54 of the 224 (24.1%) isolates were ESBLs producing Escherichia coli. Class 1 integron were detected in 63.0% of the isolates, and aadA1, aadA2, aadA5, aadA22, dfrA12, dfrA17, dfrI, aar-3 were found in the variable region and aadA gene encodes resistant to streptomycin, spectinomycin, dfr gene to trimethoprim and aar to rifampicin. We realized that aadA22 was the first time detected in China. Class 2 integron were detected in 5.6% of the isolates, Class 3 integron was detected in 3 isolates. CONCLUSION: Class 1 integron was the most commonly seen integron in Escherichia coli, encoding the resistance to streptomycin, spectinomycin and trimethoprim. Integrons were contributed to the horizontal transfer of resistant genes in the same or different species, suggesting that the antimicrobial resistance and the dissemination of integrons should be monitored.

Development of a RP-HPLC method for screening potentially counterfeit anti-diabetic drugs.

Pharmaceutical counterfeiting is becoming a serious problem in the world, especially in developing countries including China. Herein an isocratic reversed-phase high performance liquid chromatography (RP-HPLC) method was developed for screening counterfeit medicines and adulterated dietary supplement products. The developed method could be employed to separate and determine simultaneously six anti-diabetic drugs (glipizide, gliclazide, glibenclamide, glimepiride, gliquidone, repaglinide) on an isocratic solvent system using an Alltima C18 column (5 microm, 150 mmx4.6 mm) with an isocratic mobile phase of methanol-phosphate buffer (pH 3.0; 0.01 mol/L) (70:30, v/v), at a flow rate of 1.0 mL/min and at a wavelength of 230 nm. The proposed method was successfully applied to the analysis of medicinal and dietary supplement samples purchased from the local market in China.

Isolation, structure elucidation and activity of an unknown impurity of amphotericin B.

An unknown impurity named amphotericin B (2) (AmB(2)) isolated from amphotericin B (AmB) bulk material was identified as (1S,3S,5R,6R,9R,11R,15S,16R,17R,18S,19E,21E,23E,25E,27E,29E,31E,33R,35S,36R,37S)-33-[(3-amino-3,6-dideoxy-beta-D-mannopyranosyl)oxy]-1-methyloxy-3,5,6,9,11,17,37-heptahydroxy-15,16,18-trimethyl-13-oxo-14,39-dioxabicyclo[33.3.1]nonatriaconta-19,21,23,25,27,29,31-heptaene-36-carboxylic acid according to the IUPAC. The structure was elucidated by various 1D and 2D NMR techniques, mass spectrometry and by comparison with the NMR data of AmB. Its activity against Candida albicans was evaluated by comparison with AmB.

[Preparation and primary application of monoclonal antibody against benzylpenicillin].

AIM: To develop monoclonal antibody(mAb) against benzylpenicillin and to establish a Sandwich ELISA method for relative quantitative analysis of the allergen which induced penicillin allergy commonly in clinic. METHODS: Penicillin, as a kind of hapten, was conjugated with carrier protein to form complete antigen and then was used to immunize BALB/c mice. Hybridoma cells secrecting mAb against penicillin were developed. Ascites from the immunized mice were purified by caprylic acid-ammonium sulfate precipitation. The specificity of the purified antibodies was detected and the suitable antibodies were used for establishing Sandwich ELISA. RESULTS: Nine hybridoma cells stably secrecting mAb were prepared through cell fusion, screening and cloning, and five of these purified mAb had relative high affinity. The double-antibody Sandwich ELISA for relative quantitative analysis of benzylpenicilloyl protein was established with a sensitivity of 870 U/L.The average recovery rate was 107.81% and the average intra- and inter-coefficient of varitation (CV) was 6.7% and 9.3% respectively. The method was applied for relative quantitative analysis of benzylpenicilloyl protein from Group A Streptococcus Preparation. CONCLUSION: Nine hybridoma cell strains stably secreting mAb against benzylpenicillin were obtained. The double-antibody Sandwich ELISA for relative quantitative analysis of benzylpenicilloyl protein was established.

The effect of rubber closures on the haze state of ceftriaxone sodium for injection.

The migration of volatile components into the headspace of glass vials from rubber closures is a potential source of haze formation in reconstituted solutions of powders for parenteral administration. In this paper, a headspace method was used to extract volatile substances from different types of rubber closures used in ceftriaxone sodium for injection whose clarity were poor. The extracts obtained were analyzed by gas chromatography (GC)-mass spectrometry (MS). An antioxidant in rubber closures, butylated hydroxytoluene (BHT), was found to affect the haze state of ceftriaxone sodium for injection.

[Identification of related substances in rifampicin by HPLC-DAD spectroscopy correlation].

A qualitative analysis method to identify related substances of rifampicin by correlation of spectra in chromatography was established. Standard chromatographic and spectral data obtained by high-performance liquid chromatography with diode array detection (HPLC-DAD) were developed and used in identification of peaks in samples by calculating correlation coefficients (R). The comparison of spectra was expanded to three-dimensional space. Peaks in chromatography can be identified accurately and rapidly through chromatographic system change. The identification results were validated by LC-MS. The threshold of R was set to 0.99 in order to discriminate the impurities and the minimal amount for identification was 30 ng. Taking full advantage of chromatographic separate efficiency and spectral exclusiveness, the method is accurate and reproducible as a new and effective way to identify multi-components in drugs.

[Antimicrobial resistance of Escherichia coli isolates collected from inpatients and outpatients].

OBJECTIVE: To investigate the antimicrobial resistance of Escherichia coli (E. coli) isolates collected from the inpatients in the departments of medicine, surgery, and pediatrics, and intensive care unit (ICU), and from the outpatients. METHODS: Disc diffusion test was used to study the antimicrobial resistance of 3909 strains of E. coli collected from the inpatients in the departments of medicine, surgery, and pediatrics, and Intensive care unit (ICU), and from the outpatients, mostly isolated from urine, sputum, blood, and different secreta in the year 2001. WHONET 5 software was used for analysis of the antimicrobial resistance; and significant differences were tested by chi(2) to compare the resistance rates to antibiotics. RESULTS: The incidences of extended-spectrum beta-lactamases producing strains were 11.2% (195/1737), 14.3% (141/983), 17.7% (28/158), 19.7% (24/122) and 8.4% (76/909) in the strains of E. coli isolated from the inpatients in the departments of medicine, surgery, and pediatrics, and ICU and from the outpatients respectively, with a detectable rate among the outpatients significantly lower than that among the inpatients (P < 0.005), and a detectable rate among the inpatients in the department of medicine significantly lower than those among the inpatients in the department of pediatrics and ICU (both P < 0.05). The resistance rates to cefazolin, cefotaxime, gentamicin and aztreonam of the isolates from the outpatients were significantly lower than those of the inpatients (all P < 0.05). The resistance rates to amoxicillin/clavulanic acid, ceftazidime, cefepime and amikacin of the isolates from the outpatients were significantly lower than those of the inpatients in the department of surgery and ICU (all P < 0.05); The resistance rates to ciprofloxacin and trimethoprim/sulfamethoxazole of the isolates from the outpatients were significantly lower than those from the ICU patients (both P < 0.05). The resistance rates to cefazolin and cefotaxime of E. coli isolates collected from the inpatients in the department of medicine were significantly lower than those of the isolates from the department of surgery and ICU (all P < 0.01); the resistance rates to gentamicin of the isolates from the department was significantly lower than that of the isolates from the department of surgery (P < 0.05). The resistance rates to amoxicillin/clavulanic acid and aztreonam of the isolates from the department of medicine were significantly lower than those of the isolates from the ICU (both P < 0.05). The resistance rate to ciprofloxacin of isolates from the inpatients in the department of pediatrics was significantly lower than that of the other isolates (all P < 0.01). CONCLUSIONS: It is of guiding significance for empirical use of antimicrobial agents in clinic to study on the resistant rates of the strains of E. coli isolated from different departments in hospital.

[Antimicrobial resistance of Staphylococcus aureus isolates from inpatients of departments of internal medicine, surgery, and pediatrics and intensive care unit].

OBJECTIVE: To investigate the antimicrobial resistance of Staphylococcus aureus isolates obtained from inpatients of departments of internal medicine, surgery, and pediatrics and intensive care unit (ICU), and study on the differences of resistant rates among the clinical isolates. METHODS: The strains of Staphylococcus aureus were cultured and their antimicrobial resistance was assayed by disc diffusion test (K-B method) and the data was analyzed by WHO NET 5 software. chi(2) test was made to identify the significance of difference. RESULTS: 2 625 strains of Staphylococcus aureus were obtained from the clinical departments of 60 hospitals all over China, among which 1 669 strains (63.3%) were obtained from the inpatients of departments of internal medicine, surgery, and pediatrics and ICU from 1 January to 31 December 2001. Most of the strains were isolated from sputum (34.3%, 572/1 669), secretion (13.2%, 221/1 669), pus (11.7%, 195/1 669), blood (10.2%, 171/1 669), and wound (5.6%, 94/1 669). The resistant rates of Staphylococcus aureus isolates from the inpatients in department pediatrics of to oxacillin, gentamicin, clindamycin, ciprofloxacin, levofloxacin, and chloramphenicol were 23.3%, 16.1%, 29.3%, 11.2%, 4.0% and 14.4% respectively, all significantly lower than those of the isolates from the inpatients of the departments of internal medicine and surgery, and ICU (all P < 0.001). The resistant rates of Staphylococcus aureus isolates from the inpatients of departments of internal medicine and surgery to oxacillin, gentamicin, clindamycin, ciprofloxacin, and levofloxacin were significantly lower than those of isolates from the patients of ICU (all P < 0.001). CONCLUSION: A high isolation rate of multi-drug resistant Staphylococcus aureus among the inpatients of departments of internal medicine, surgery, and pediatrics and ICU. It is important to select appropriate antimicrobial agents based on the origin of bacterial strains and avoid blindness before the results of drug sensitivity are obtained.

[Analysis of the response factors of different aminoglycoside antibiotics detected by evaporative light-scattering detector].

AIM: To analyze if the response factors of different aminoglycoside antibiotics detected by evaporative light-scattering detector (ELSD) are the same. If they are, then ELSD can be applied to the quality analysis of this class of antibiotics. METHODS: The response factors of five different aminoglycosides (amikacin, sisomicin, netilmicin, etimicin and vertilmicin) detected by ELSD were determined by using a Diamonsil C18 column (150 mm x 4.6 mm, 5 microns) as analytical column and 0.2 mol.L-1 trifluoroacetic acid-methanol (94:6) as mobile phase at a flow rate of 0.6 mL.min-1, the temperature of the drift tube was set at 110 degrees C, and the flow of carrier gas at 2.80 L.min-1. Detector responses (A) and the amount of injection of each substance (m) were fitted to the logarithmic regression: logA = blogm + loga. RESULTS: The linear regression equation obtained were amikacin: Y = 1.46X + 5.07, gamma = 0.9997; sisomicin: Y = 1.51X + 5.03, gamma = 0.9997; netilmicin: Y = 1.52X + 4.88, gamma = 1.000; etimicin: Y = 1.46X + 4.85, gamma = 0.9999; vertilmicin: Y = 1.41X + 4.90, gamma = 0.9998. The differences between them were negligible. CONCLUSION: Different aminoglycosides can give the same responses with ELSD detection. So, the HPLC-ELSD methods can be applied to the analysis of impurities, the control of the ratio of multi-components drug and the determination of new substances by using another substance as reference, etc.

[Study on water of crystallization in tazobactam].

AIM: To investigate whether tazobctam has crystallization water. METHODS: In order to establish a method for water content determination in tazobctam, many methods including Karl Fischer titration, weight loss on drying, TGA, DSC and X-ray diffraction experiment of an orthorhombic form were studied. RESULTS: The water content of the same batch tazobactam determined by different mthods was different. CONCLUSION: The results showed that one mole tazobatam contains half mole water of crystallization and the strength of attraction between tazobatam molecule and water molecule is rather strong.