Haemolysis Effect Estimation of Doxycycline Hyclate 150 mgDelay Release Tablet in Bio-analysis (Human Plasma) by LiquidChromatography-Tandem Mass Spectrometry
A fast, simple and particular method for estimation of Doxycycline in healthy human plasma was validated using Minocycline as IS. The analyte and IS were extracted from plasma using SPE. The compound was estranged on a RP column with an isocratic mobile phase consisting of 0.1% formic acid in water and acetonitrile (12:88, v/v), and detected by tandem mass spectrometry in positive ion mode. The ion transition recorded in several reaction monitoring mode were m/z 294.1→225.1 for Doxycycline and m/z 286.1→217.1 for IS. Linearity in plasma was observed over the concentration range 0.3-30 ng/mL for Doxycycline. The mean recovery for Doxycycline was 83.7%, with a lower limit of quantification of 0.3 ng/mL. The coefficient of variation of the assay was less than 6.8%, and accuracy of 96.1% to 102.2%. The validated method was applied to bioequivalence study of 150 mg Doxycycline Hyclate tablet in healthy human volunteers. The validated method was used to expose study samples of bioequivalence study of 150 mg Doxycycline Hyclate delay release tablet in 36 healthy human volunteers. Total 50 samples from individual volunteers identified as Haemolyzed, which were analyze initial and repeat again to cross check the method reproducibity for Haeamolysis effect and compared which found acceptable range. Bioequivalence was prove for test and reference using validated method to experimental samples (Figure 1).
Validated UHPLC-MS/MS method for quantification of doxycycline in abdominal aortic aneurysm patients.
AIM
There is a strong evidence that doxycycline can benefit abdominal aortic aneurysms patients because of its ability to inhibit matrix metalloproteinase enzymes. There is a need for a specific quantification method for doxycycline in these patients. We report herein the development and validation of a selective, specific, simple and rapid UHPLC-MS/MS method for doxycycline.


RESULTS
The assay was linear (r2 > 0.994) over a concentration range of 0.010-7.005 μg/ml. This validated method has good lower limit of quantification (LLOQ) (10 ng/ml), accuracies (89.1-103.4%), precision (≤7.0%) and extraction recoveries (95.8%). Doxycycline was stable during short- and long-term storage.


CONCLUSION
The assay is reliable and has been successfully applied to serum samples obtained from the patients of N-TA3CT clinical study.
Fragment Rotational State Distributions From The Dissociation Of NeIBr: Experimental And Theoretical Results
The IBr fragment rotational state distributions that result when the NeIBr van der Waals molecule undergoes vibrational predissociation have been measured in a pump–probe laser‐induced fluorescence experiment. Independent of initial vibrational state and the number of quanta of vibrational energy lost from the I–Br coordinate, the rotational distributions extend over the full range of energetically accessible states. From the observation of energetic constraints on the rotational distribution, the dissociation energy (D0) is calculated to be 65.5±1.2 cm−1 for the A electronic state, v=16. For the X electronic state, v=0, D0=71.8±1.2 cm−1. Quantum mechanical bound state calculations carried out on a model A electronic state potential energy surface are in quantitative agreement with this result. The rotational distributions are broader than that predicted by either a Franck–Condon or classical impulsive model for the dissociation. The distributions are qualitatively in accord with classical trajectory calc...