Development of a simple and sensitive HPLC-MS/MS method for determination of diazepam in human plasma and its application to a bioequivalence study

We developed a simple, sensitive, and effective ultra-performance liquid chromatography/tandem mass spectrometry (HPLC-MS/MS) method with an electrospray ionization (ESI) interface in multiple reaction monitoring (MRM) and positive ion modes to determine diazepam concentrations in human plasma using voriconazole as an internal standard (IS). Diazepam and IS were detected at transition 285.2→193.1 and 350.2→127.1, respectively. After liquid-liquid extraction (LLE) using 1.2 ml of ethyl acetate:n-hexane (80:20, v/v), diazepam and IS were eluted on a Phenomenex Cadenza CD-C18 column (150 × 3.0 mm, 3 µm) with an isocratic mobile phase (10 mM ammonium acetate in water:methanol [5:95, v/v]) at a flow rate of 0.4 mL/min. The peak retention time was 2.32 min for diazepam and 2.01 min for IS, respectively. The lower limit of quantitation (LLOQ) was 0.5 ng/mL (S/N > 10) using 50 µL of plasma, and no interferences were observed in chromatograms. Our analytical method was fully validated and successfully applied to a bioequivalence study of two formulations of diazepam in healthy Korean volunteers.

Risk analysis according to placental penetration by amniocentesis needle / 대한산부인과학회잡지

OBJECTIVES: To evaluate pregnancy outcomes after placental needle penetration during midtrimester diagnostic amniocentesis. METHODS: We collected 726 singleton pregnancy cases from 1054 pregnancies of midtrime-ster diagnostic amniocentesis, and analysed pregnancy outcomes after the procedure based on medical records. To compare the outcomes, we divided 726 cases into two groups; placental penetration group by aspiration needle(170 cases) and non-penetration group(556 cases). RESULTS: There were no statistically significant differences between two groups about maternal age and gestational age at the time of procedure, and the distribution of amniocentesis indication. In comparison of complications between two groups after procedure, a. There was no statistically significant difference in amniotic fluid leakage: in penetration group, 1 case (0.58%) and in non-penetration group, 5 cases(0.89%) were observed. b. There was no statistically significant difference in vaginal bleeding: in penetration group, 2 cases (1.18%) and in non-penetration group, 3 cases(0.54%) were observed. c. There was no statistically significant difference in developing abruptio placentae: in penetration group, no case developed and in non-penetration group, one case(0.18%) was observed. d. As for fetal loss, there was no statistically significant difference : in penetration group, 4 cases (2.35%) and in non-penetration group, 10 cases(1.80%) were occurred. e. As for birth weight, there was no statistically significant difference : in penetration group, 3.26+/-0.8 kg and in non-penetration group, 3.21+/-0.9 kg were measured. CONCLUSION: Our study shows that placental penetration by aspiration needle during diagnostic mid-trimester amniocentesis does not increase the risk of post-procedure complication.

A Case of Meconium Pseudocyst which was Prenatally Diagnosed / 대한산부인과학회잡지

Prenatal Ultrasonographic findings of meconium peritonitis show calcificalion, and abdominal echogenic masses such as pseudocyst. Also, we can find availability of 3 dimensional ultrasonography above these descriptions. We present a case of meconium peritonitis in uterus which was diagnosed by means of prenatal 2D & 3D ultrasonography with brief review of literatures.