Impurities in a morphine sulfate drug product identified as 5-(hydroxymethyl)-2-furfural, 10-hydroxymorphine and 10-oxomorphine

Influence of Light Irradiation on the Degradation of Dezocine in Injections

Dezocine, which is well-known as an analgesic, had about 45% share of the Chinese opioid analgesic market. Since drug products containing impurities could bring serious health consequences, it was important to control the generation of impurities and degradation products in the dezocine product. In this study, two kinds of photodegradation products (i.e., degradation product 1 and degradation product 2) in the dezocine injection were isolated using high-performance liquid chromatography. The possible structures of the photodegradation products were identified using both high-resolution mass spectrometry and nuclear magnetic resonance spectroscopy. In addition, the possible generation mechanism showed that degradation product 1 was the oxidation product of dezocine, and degradation product 2 was the coupled dimer of dezocine. Finally, we found that the degradation rate of dezocine increased with the increase in light intensity. Moreover, the degradation of dezocine easily occurred under ultraviolet light in comparison with visible light. A deeper insight into the generation of the photodegradation products in the dezocine injection would directly contribute to the safety of drug therapy based on the dezocine injection by minimizing the degradant/impurity-related adverse effects of drug preparations.

Chemical Changes during Fermentation of Abhayarishta and its Standardization by HPLC-DAD

Abhayarishta is an Ayurvedic formulation prepared traditionally by the fermentation of the decoction of Terminalia chebula (pericarp), Vitis vinifera (fruits), Embelia ribes (fruits) and Madhuca indica (flowers). In the present communication, chemical changes occurring during fermentation in Abhayarishta have been studied for the purpose of its standardization. An HPLC-DAD method for quantitative estimation of selected marker constituents in the formulation has been developed and validated. A comparison of decoction and final processed formulation revealed that major polyphenolics (chebulagic and chebulinic acid) of T. chebula were hydrolyzed to their respective monomers and, consequently, there was an increase in the amount of chebulic acid, gallic acid, ellagic acid and ethyl gallate after fermentation. 5-Hydroxymethyl furfural (5-HMF) was also found in the formulation. Thus, emphasis is laid upon consideration of processing methods of formulation which has been lacking in the standardization of most of Ayurvedic formulations.

The use of mixed-mode ion-exchange solid phase extraction to characterize pharmaceutical drug degradation

Solid phase extraction (SPE) has been utilized extensively in the pharmaceutical industry for the isolation of pharmaceuticals from interfering biological matrices and the purification and concentration of impurities and degradation products present in analytical samples. The work described herein involves the novel use of mixed-mode ion-exchange solid phase extraction to characterize degradation products of several pharmaceutical drugs, thereby giving important clues to their structure and sites of reactivity. Several examples of the use of mixed-mode ion-exchange solid phase extraction to illustrate the utility of this technique are presented.

Identification of hexose hydrolysis products in metabolic flux analytes: a case study of levulinic acid in plant protein hydrolysate

Biosynthetically directed fractional (13)C labeling, a popular methodology of metabolic flux analysis, involves culture on a mixture of (13)C and (12)C substrates and preparation a 'metabolic flux analyte' (typically protein hydrolysate) from the biomass. Metabolic flux analytes prepared from complex eukaryotes may contain additional compounds than those prepared from microorganisms. We report the presence of such compounds (hexose hydrolysis products) in a plant metabolic flux analyte (acid hydrolyzed protein from soybean embryos). We designed NMR experiments to systematically identify these compounds, and found that they were levulinic acid (LVA; major) and hydroxyacetone (HyA; minor). These acid hydrolysis products of hexoses (glucose and mannose) were generated during acid hydrolysis of glycosylating sugars (glucosamine and mannose) associated with soybean embryo protein. Analysis of LVA by two-dimensional [(13)C, (1)H] NMR and measurement of its J-coupling constants revealed long-range coupling between atoms C3 and C5, which enables LVA to provide more isotopomer information than its precursor hexose. Furthermore, we found that LVA and HyA preserve the isotopomeric composition of the metabolic hexose from which they are derived. An important consequence of these results is that comparison of LVA and HyA isotopomers from two separate metabolic flux analytes (protein hydrolysate and starch hydrolysate) from the same plant tissue can distinguish between parallel glycolysis and pentose phosphate pathways in different subcellular compartments.

Simultaneous determination of formic acid and formaldehyde in pharmaceutical excipients using headspace GC/MS

Formic acid and its esters, as well as formaldehyde, are trace impurities that are often present in pharmaceutical excipients. These trace impurities can potentially react with amino and/or hydroxyl groups in drugs to form significant levels of degradants. To select the appropriate excipients for a stable formulation, a gas chromatography/mass spectrometry (GC/MS) method was developed and validated for the rapid screening of trace amounts of residual formic acid, its esters and formaldehyde in pharmaceutical excipients. Samples were dissolved or dispersed in acidified ethanol to convert formic acid and formaldehyde to ethyl formate and diethoxymethane, respectively. Identification was conducted using a GC/MS system under scan mode and quantified using a selected ion monitoring (SIM) mode. Evaluation of the mass spectra of ethyl formate and diethoxymethane in the samples indicated that the method is specific. The limits of quantitation of the method were 0.5 ppm for formic acid and 0.2 ppm for formaldehyde. The precision of the method was demonstrated by the acceptable R.S.D. (<or=10%) over a linear range of 0.5-10,000 ppm. The accuracy of the method was within 80-120% over the linearity range. The amounts of formic acid and formaldehyde in commonly used pharmaceutical excipients is reported.

5-(Hydroxymethyl)-2-furfural: a selective inhibitor of DNA polymerase lambda and terminal deoxynucleotidyltransferase

5-(Hydroxymethyl)-2-furfural (HMF), a pyrolysate of carbohydrate isolated from instant coffee (Coffea arabica L.), selectively inhibits the activities of mammalian DNA polymerase lambda (pol lambda) and terminal deoxynucleotidyltransferase (TdT) which are family X pols, in vitro. The compound influenced neither the activities of replicative DNA polymerases such as alpha, delta, and epsilon, nor even the activity of pol beta which is from the same family and thought to have a very similar three-dimensional structure to the pol beta-like region of pol lambda. Since parts of HMF such as furan, furfuryl alcohol, and 2-furaldehyde did not influence the activities of any enzymes tested, the substituted form of furan with a hyroxymethyl group and a formyl group might be important for the inhibition of pol lambda and TdT. The inhibitory effect of HMF on intact pol lambda (i.e., residues 1-575), a truncated pol lambda lacking the N-terminal BRCA1 C-terminus domain (133-575, del-1 pol lambda) and another truncated pol lambda lacking the N-terminal proline-rich region (245-575, del-2 pol lambda) was dose-dependent, and 50% inhibition was observed at a concentration of 26.1, 10.3, and 4.6 microM, respectively. The IC(50) value of HMF for TdT was the same as that for del-2 pol lambda (5.5 microM). The HMF-induced inhibition of both pol lambda and TdT activities was competitive with respect to both the DNA template-primer and the dNTP substrate. On the basis of these results, HMF was suggested to bind to the pol beta-like region of pol lambda and TdT.

Syntheses of 10-Oxo, 10.ALPHA.-Hydroxy, and 10.BETA.-Hydroxy Derivatives of a Potent .KAPPA.-Opioid Receptor Agonist, TRK-820

Syntheses of 10-oxo, 10alpha-hydroxy, and 10beta-hydroxy derivatives of a potent kappa-opioid receptor selective agonist, TRK-820, are described. These derivatives were supposed to be potential degradation products in formulation of TRK-820 as a result of autoxidation. 10-Oxo-TRK-820 11 was derived from 10-oxo-4,5-epoxymorphinan 14 in 10 steps in 32% overall yield. Reduction of the 10-oxo group in 4,5-epoxymorphinan with NaBH(4) gave 10beta-hydroxy-4,5-epoxymorphinan, exclusively. A stepwise inversion method of the 10beta-hydroxy group to produce 10alpha-hydroxy-4,5-epoxymorphinan was established. By HPLC analyses, 10alpha-hydroxy-TRK-820 12 was confirmed to be one of the degradation products in developing formulation of TRK-820.