OBJECTIVES

In response to the need for a simple and fast way of ensuring that generic drugs especially those that contain rifampicin are bioequivalent with reference drugs, this study validated an ultra-high-performance liquid chromatography (UHPLC) method of quantifying rifampicin in human plasma. The study also validated the method's selectivity, linearity, sensitivity, accuracy, precision, and the absence of a carry-over effect adhering to the Philippine Food and Drug Administration guidelines.

Plasma samples were prepared via protein precipitation using methanol containing ascorbic acid. Three microliters (3 uL) of the prepared samples were then analyzed in a Waters Acquity H-Class UPLC® system coupled to a tunable ultraviolet (TUV) detector with an attached UPLC® BEH C-18 column using a developed and optimized method. Briefly, the column temperature was set to 40°C and the sample temperature was set to 10°C. Elution was done using a linear gradient flow of a water-acetonitrile mixture that started with 45% acetonitrile increasing to 60% acetonitrile at 0.5 minutes and back to 45% acetonitrile at 3 minutes and having a constant flow rate of 0.5 mL/min. Detection was done at 340 nm. Method validation was performed following the ICH guidelines for Bioanalytical Method Validation, the same guidelines referenced by the ASEAN Guideline for Harmonisation of Standards and the Philippine Food and Drug Administration (FDA).

The method had an analysis time of 3 minutes wherein rifampicin eluted at 1.4 minutes while the internal standard, rifapentine (IS) eluted at 1.7 minutes. Since no co-eluting endogenous materials were observed for the rifampicin and the internal standard, the method was confirmed to be selective. Its linearity over the range of 2 ug/mL to 25 ug/mL has been validated where it has a limit of detection (LOD) and limit of quantification (LOQ) values of 0.64 ug/mL and 1.94 ug/mL, respectively. The interday and intraday precision, reported as % coefficient of variance (%CV), and interday and intraday accuracy, reported as %error all within the limits of ±20% for the LLOQ and ±15% for the rest indicating its reliability and reproducibility. Lastly, due to the nature of the injection of the sample into the system, wherein a blank immediately follows the highest concentration standard, the method has been cleared of a carry-over effect.

The study successfully validated a UHPLC method of quantifying rifampicin in human plasma. Due to the sample processing method used and the chromatographic conditions set, the method can prepare and analyze samples in a simple yet fast, sensitive, reliable, and reproducible manner. The method can be applied in bioavailability and bioequivalence studies of rifampicin.

In this experiment, self-assembled nanoparticles(SANs) were prepared by the pH-driven method, and Her-HCP SAN was constructed by using herpetrione(Her) and Herpetospermum caudigerum polysaccharides(HCPs). The average particle size and polydispersity index(PDI) were used as evaluation indexes for process optimization, and the quality of the final formulation was evaluated in terms of particle size, PDI, Zeta potential, and microstructure. The proposed Her-HCP SAN showed a spheroid structure and uniform morphology, with an average particle size of(244.58±16.84) nm, a PDI of 0.147 1±0.014 8, and a Zeta potential of(-38.52±2.11) mV. Her-HCP SAN significantly increased the saturation solubility of Her by 2.69 times, with a cumulative release of 90.18% within eight hours. The results of in vivo unidirectional intestinal perfusion reveal that Her active pharmaceutical ingredient(API) is most effectively absorbed in the jejunum, where both K_a and P_(app) are significantly higher compared to the ileum(P<0.001). However, the addition of HCP leads to a significant reduction in the P_(app) of Her in the jejunum(P<0.05). Furthermore, the formation of the Her-HCP SAN results in a notably lower P_(app) in the jejunum compared to Her API alone(P<0.001), while both K_a and P_(app) in the ileum are significantly increased(P<0.001, P<0.05). The absorption of Her-HCP SAN at different concentrations in the ileum shows no significant differences, and the pH has no significant effect on the absorption of Her-HCP SAN in the ileum. The addition of the transporter protein inhibitors(indomethacin and rifampicin) significantly increases the absorption parameters K_a and P_(app) of Her-HCP SAN in the ileum(P<0.05,P<0.01), whereas the addition of verapamil has no significant effect on the intestinal absorption parameters of Her-HCP SAN, suggesting that Her may be a substrate for multidrug resistance-associated protein 2 and breast cancer resistance proteins but not a substrate of P-glycoprotein.
Nanoparticles/metabolism* ; Polysaccharides/pharmacokinetics* ; Intestinal Absorption/drug effects* ; Animals ; Rats ; Particle Size ; Drugs, Chinese Herbal/pharmacokinetics* ; Male ; Rats, Sprague-Dawley ; Drug Carriers/chemistry* ; Drug Compounding ; Cucurbitaceae/chemistry*

Based on the pharmacokinetics theory, this study investigated the pharmacokinetic characteristics of albiflorin, paeoniflorin, wogonoside, and wogonin in normal and febrile rats and summarized absorption and elimination rules of Dayuanyin in them to provide reference for further development and clinical application of Dayuanyin. Blood samples were taken from the fundus venous plexus of normal and model rats after intragastric administration of Dayuanyin at different time points. The concentration of each substance in blood was determined by ultra performance liquid chromatography-triple quadrupole mass spectrometry(UPLC-MS/MS) technique at different time points. DAS 2.0, a piece of pharmacokinetics software, was used to calculate the pharmacokinetic parameters of each component. The results show that the 4 components had good linear relationship in their respective ranges, and the results of methodological investigation met the requirements. The pharmacokinetic parameters of C_(max), T_(max), t_(1/2), AUC_(0-t), AUC_(0-∞), and MRT_(0-t) were calculated by the DAS 2.0 non-compartmental model. Compared with those in the normal group, C_(max) and AUC_(0-t) of the 4 components in the model group were significantly increased. There were significant differences in the pharmacokinetic characteristics between the normal and model groups, suggesting that the absorption and elimination of Dayuanyin may be affected by the changes of internal environment of the body in different physiological states.
Animals ; Rats ; Drugs, Chinese Herbal/administration & dosage* ; Male ; Rats, Sprague-Dawley ; Fever/metabolism* ; Tandem Mass Spectrometry ; Chromatography, High Pressure Liquid ; Glucosides/pharmacokinetics* ; Monoterpenes

In this study, the pharmacokinetic characteristics and tissue distribution of cannabidiol(CBD)/γ-polyglutamic acid-g-cholesterol(γ-PGA-g-CHOL) nanomicelles [CBD/(γ-PGA-g-CHOL)NMs] were investigated by pharmacokinetic experiments, and the effect of CBD/(γ-PGA-g-CHOL)NMs on the lipopolysaccharide(LPS)-induced inflammatory damage of cells was evaluated by cell experiments. CBD/(γ-PGA-g-CHOL)NMs were prepared by dialysis. The CBD concentrations in the plasma samples of male SD rats treated with CBD and CBD/(γ-PGA-g-CHOL)NMs were investigated, and the pharmacokinetic parameters were calculated and compared. UPLC-MS/MS was employed to determine the concentration of CBD in tissue samples. The heart, liver, spleen, lung, kidney, and muscle samples were collected at different time points to explore the tissue distribution of CBD and CBD/(γ-PGA-g-CHOL)NMs. The Caco-2 cell model of LPS-induced inflammation was established, and the cell viability, transepithelial electrical resistance(TEER), and secretion levels of inflammatory cytokines were determined to compare the anti-inflammatory activity between the two groups. The results showed that CBD/(γ-PGA-g-CHOL)NMs had the average particle size of(163.1±2.3)nm, drug loading of 8.78%±0.28%, and encapsulation rate of 84.46%±0.35%. Compared with CBD, CBD/(γ-PGA-g-CHOL)NMs showed increased peak concentration(C_(max)) and prolonged peak time(t_(max)) and mean residence time(MRT_(0-t)). Within 24 h, the tissue distribution concentration of CBD/(γ-PGA-g-CHOL)NMs was higher than that of CBD. In addition, both CBD and CBD/(γ-PGA-g-CHOL)NMs significantly enhanced Caco-2 cell viability and TEER, lowered the secretion levels of inflammatory cytokines, and alleviated inflammation. Moreover, CBD/(γ-PGA-g-CHOL)NMs demonstrated stronger anti-inflammatory effect. It can be inferred that γ-PGA-g-CHOL blank nanomicelles are good carriers of CBD, being capable of prolonging the circulation time of CBD in the blood, improving the bioavailability and tissue distribution concentration of CBD, and protecting against LPS-induced inflammatory injury. The findings can provide an experimental basis for the development and clinical application of oral CBD preparations.
Animals ; Cannabidiol/administration & dosage* ; Polyglutamic Acid/analogs & derivatives* ; Humans ; Male ; Rats ; Rats, Sprague-Dawley ; Anti-Inflammatory Agents/administration & dosage* ; Micelles ; Caco-2 Cells ; Cholesterol/pharmacokinetics* ; Tissue Distribution ; Nanoparticles/chemistry*

In this study, the reductive amination method was used to label IR783 on Astragalus polysaccharides(APS) for the first time, which was verified by ultraviolet-visible spectroscopy and infrared spectroscopy. Quantitative analysis methods of APS-IR783 in plasma and various tissue were established using a multifunctional microplate reader. The pharmacokinetics and tissue distribution of APS-IR783 in mice were investigated after a single intravenous injection of 30 mg·kg~(-1) APS-IR783, and pharmacokinetic parameters were calculated using DAS 2.0 software. The results showed that the APS used had a mass fraction of 93.69%, a relative molecular weight of 1.55×10~5, and a polydispersity index(PDI, M_w/M_n) of 1.73, close to a homogeneous polysaccharide. The IR783 labeling yield reached 86.50%, and the content of IR783 in APS-IR783 was 0.72%. After a single intravenous injection of 30 mg·kg~(-1), the pharmacokinetic parameters of APS in mouse plasma were as follows: T_(max) was(0.67±0.26) h; C_(max) was(1 599.29±159.30) mg·L~(-1); T_(1/2α) and T_(1/2β) were(2.29±3.06) h and(0.44±0.05) h, respectively; AUC_(0-t) was(23 398.91±2 907.03) mg·h·L~(-1); AUC_(0-∞) was(27 710.55±3 506.55) mg·h·L~(-1); MRT_(0-∞) was(34.38±12.59) h; CL was 0.001 L·h~(-1)·kg~(-1); V_z was(0.042±0.017) L·kg~(-1). The in vivo biodistribution study demonstrated that the in vivo exposure ratios of APS in different tissue were in the following order: spleen > liver > kidney > lung > heart > small intestine > muscle > large intestine > brain > stomach, where the top five tissue accounted for 87.54% of the total area under the curve(AUC). This study successfully labeled APS with a water-soluble near-infrared fluorescent probe of IR783 for the first time and revealed the pharmacokinetics and tissue distribution of APS in mice. The paper provides detailed in vivo behavior of APS after intravenous injection, which lays the foundation for the development and utilization of APS and related natural medicines.
Animals ; Mice ; Polysaccharides/chemistry* ; Tissue Distribution ; Astragalus Plant/chemistry* ; Male ; Drugs, Chinese Herbal/chemistry* ; Fluorescent Dyes/pharmacokinetics* ; Female

The main active compound, 3,4-dihydroxyacetophenone(3,4-DHAP), in the leaves of Ilex pubescens var. glaber, exhibits various pharmacological activities, including vasodilation and heart protection. Currently, natural extraction and chemical synthesis are the primary methods for obtaining 3,4-DHAP, but both approaches have inherent challenges. To address these problems, this study explored the whole-cell bioconversion of 1-(4-hydroxyphenol)-ethanol to 3,4-DHAP using recombinant Escherichia coli, cultivated in a green, cost-effective medium at room temperature and atmospheric pressure. Firstly, this study successfully constructed recombinant E. coli S1, which contained only the HpaBC gene, and recombinant E. coli S3, which contained both the Hped and HpaBC genes. The ability of S1 and S3 to synthesize 3,4-DHAP from their respective substrates was then evaluated through whole-cell bioconversion. Based on these results, the effects of four factors, i.e., substrate concentration, IPTG concentration, induction temperature, and transformation temperature, on the whole-cell bioconversion yield of S3 were investigated using an orthogonal experiment. The results showed that the factors influenced the yield in the following order: transformation temperature > induction temperature > IPTG concentration > substrate concentration. The optimal conditions were found to be a transformation temperature of 35 ℃, IPTG concentration of 0.1 mmol·L~(-1), induction temperature of 25 ℃, and substrate concentration of 10 mmol·L~(-1). Finally, the effect of transformation time on the yield of 3,4-DHAP was further examined under the optimal conditions. The results indicated that as the transformation time increased, the yield of 3,4-DHAP steadily increased. The highest yield of 260 mg·L~(-1) with a productivity of 17% was achieved after 72 hours of transformation. In conclusion, this study successfully achieved the whole-cell bioconversion of 1-(4-hydroxyphenol)-ethanol to 3,4-DHAP using recombinant E. coli for the first time, laying the groundwork for further optimization and development of the biosynthesis of 3,4-DHAP.
Escherichia coli/genetics* ; Acetophenones/chemistry* ; Ethanol/chemistry* ; Drugs, Chinese Herbal/chemistry* ; Biotransformation

The study aims to elucidate the existence forms(original constituents and metabolites) of Notoginseng Radix et Rhizoma in rats and reveal its metabolic pathways. After Notoginseng Radix et Rhizoma was administered orally once a day for seven consecutive days to rats, all urine and feces samples were collected for seven days, while the blood samples were obtained 6 h after the last administration. Using the ultra high performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry(UHPLC-Q-TOF-MS/MS) technique, this study identified 6, 73, and 156 existence forms of Notoginseng Radix et Rhizoma in the rat plasma, urine, and feces samples, respectively. Among them, 101 compounds were identified as new existence forms, and 13 original constituents were identified by comparing with reference compounds. The metabolic reactions of constituents from Notoginseng Radix et Rhizoma were mainly deglycosylation, dehydration, hydroxylation, hydrogenation, dehydrogenation, acetylation, and amino acid conjugation. Furthermore, the possible in vivo metabolic pathways of protopanaxatriol(PPT) in rats were proposed. Through comprehensive analysis of the liquid chromatography-mass spectrometry(LC-MS) data, isomeric compounds were discriminated, and the planar chemical structures of 32 metabolites were clearly identified. According to the literature, 48 original constituents possess antitumor and cardiovascular protective bioactivities. Additionally, 32 metabolites were predicted to have similar bioactivities by SuperPred. This research lays the foundation for further exploring the in vivo effective forms of Notoginseng Radix et Rhizoma.
Animals ; Rats ; Drugs, Chinese Herbal/pharmacokinetics* ; Rhizome/metabolism* ; Male ; Rats, Sprague-Dawley ; Chromatography, High Pressure Liquid ; Panax notoginseng/chemistry* ; Tandem Mass Spectrometry ; Feces/chemistry*

This study aims to explore the pharmacodynamic material basis of Jinbei Oral Liquid(JBOL) against idiopathic pulmonary fibrosis(IPF) based on serum pharmacochemistry and network pharmacology. The ultra-high performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry(UHPLC-Q-TOF-MS/MS) technology was employed to analyze and identify the components absorbed into rat blood after oral administration of JBOL. Combined with network pharmacology, the study explored the pharmacodynamic material basis and potential mechanism of JBOL against IPF through protein-protein interaction(PPI) network construction, "component-target-pathway" analysis, Gene Ontology(GO) functional enrichment, and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment analysis. First, a total of 114 compounds were rapidly identified in JBOL extract according to the exact relative molecular mass, fragment ions, and other information of the compounds with the use of reference substances and a self-built compound database. Second, on this basis, 70 prototype components in blood were recognized by comparing blank serum with drug-containing serum samples, including 28 flavonoids, 25 organic acids, 4 saponins, 4 alkaloids, and 9 others. Finally, using these components absorbed into blood as candidates, the study obtained 212 potential targets of JBOL against IPF. The anti-IPF mechanism might involve the action of active ingredients such as glycyrrhetinic acid, cryptotanshinone, salvianolic acid B, and forsythoside A on core targets like AKT1, TNF, and ALB and thereby the regulation of multiple signaling pathways including PI3K/AKT, HIF-1, and TNF. In conclusion, JBOL exerts the anti-IPF effect through multiple components, targets, and pathways. The results would provide a reference for further study on pharmacodynamic material basis and pharmacological mechanism of JBOL.
Drugs, Chinese Herbal/pharmacokinetics* ; Animals ; Tandem Mass Spectrometry ; Network Pharmacology ; Rats ; Chromatography, High Pressure Liquid ; Rats, Sprague-Dawley ; Male ; Idiopathic Pulmonary Fibrosis/metabolism* ; Humans ; Administration, Oral ; Protein Interaction Maps/drug effects* ; Signal Transduction/drug effects*

The study aims to explore the herb-drug interaction between Xuefu Zhuyu Decoction(XFZY) and atorvastatin(AT). Reverse transcription polymerase chain reaction(RT-PCR) was used to analyze the transcription levels of proteins related to drug metabolism and transport in LS174T cells, detect the intracellular drug uptake under various substrate concentrations and incubation time, and optimize the model reaction conditions of transporter multidrug resistance protein 1(MDR1)-specific probe Rhodamine 123 and AT to establish a cell model for investigating the human intestinal drug interaction. The cell counting kit-8(CCK-8) method was adopted to evaluate the cytotoxicity of XFZY on LS174T cells. After a single and continuous 48 h culture with XFZY, AT or Rhodamine 123 was added for co-incubation. The effect and mechanism of XFZY on human intestinal absorption of AT were analyzed by measuring the intracellular drug concentrations and transcription levels of related transporters and metabolic enzymes. The results of in vitro experiments show that a single co-culture with a high concentration of XFZY significantly increases the intracellular concentrations of Rhodamine 123 and AT. A high concentration of XFZY co-culture for 48 h increases the AT uptake level, significantly induces the CYP3A4 and UGT1A1 gene expression levels, and inhibits the OATP2B1 gene expression level. To compare with the evaluation results of the in vitro human cell model, the pharmacokinetic experiment of XFZY combined with AT was carried out in rats. Sprague-Dawley(SD) rats were randomly divided into a blank control group and an XFZY group. After 14 days of continuous intragastric administration, AT was given in combination. The liquid chromatography-mass spectrometry(LC-MS)/MS method was used to detect the concentrations of AT and metabolites 2-hydroxyatorvastatin acid(2-HAT), 4-hydroxyatorvastatin acid(4-HAT), atorvastatin lactone(ATL), 2-hydroxyatorvastatin lactone(2-HATL), and 4-hydroxyatorvastatin lactone(4-HATL) in plasma samples, and the pharmacokinetic parameters were calculated. Pharmacokinetic analysis in rats shows that continuous administration of XFZY does not significantly change the pharmacokinetic characteristics of AT in rats, but the AUC_(0-6 h) values of AT and metabolites 2-HAT, 4-HAT, and 2-HATL increase by 21.37%, 14.94%, 12.42%, and 6.68%, respectively. The metabolic rate of the main metabolites shows a downward trend. The study indicates that administration combined with XFZY can significantly increase the uptake level of AT in human intestinal cells and increase the exposure level of AT and main metabolites in rats to varying degrees. The mechanism may be mainly due to the inhibition of intestinal MDR1 transport activity.
Animals ; Drugs, Chinese Herbal/administration & dosage* ; Atorvastatin/administration & dosage* ; Humans ; Rats ; Rats, Sprague-Dawley ; Male ; Intestines/cytology* ; Intestinal Mucosa/metabolism* ; Herb-Drug Interactions ; Cytochrome P-450 CYP3A/metabolism* ; Intestinal Absorption/drug effects*

Traditional Chinese medicine(TCM) processing is a specialized pharmaceutical technique with the primary objective of reducing the toxicity of medicinal substances. Euphorbia pekinensis, E. ebracteolata, and E. fischeriana, all belonging to Euphorbiaceae, are classified as drastic purgative herbs, traditionally used for eliminating retained water, reducing swelling, resolving toxicity, and dispersing masses. However, these herbs are also associated with adverse effects such as abdominal pain and diarrhea. Accordingly, they are commonly processed with vinegar, milk, or Terminalia chebula decoction to reduce the toxicity. This review summarizes the chemical constituents, pharmacological activities, historical evolution of processing methods, and detoxification mechanisms of the three toxic Euphorbia species. The primary toxic constituents are terpenoids. Specifically, E. ebracteolata and E. fischeriana are rich in diterpenoids, while E. pekinensis contains diterpenoids, triterpenoids, and sesquiterpenoids. Studies have shown that vinegar processing promotes structural transformations of diterpenoids, including ether bond hydrolysis, lactone ring opening, esterification, oxidation, and epoxide ring cleavage, thereby reducing the content and toxicity of these compounds. Milk processing facilitates the dissolution of toxic components into the residual liquid of excipients, leading to decreases in their concentrations in the final decoction pieces. Processing with T. chebula decoction raises the levels of tannin-derived phenolic acids, which antagonize the adverse effects of the intestine. These findings reveal a shared detoxification pattern among the three toxic herbs. Accordingly, this review proposes the concept of a shared detoxification mechanism for toxic herbs belonging to the same family or genus. That is, toxic herbs belonging to the same taxon often exhibit similar toxicological profiles and can undergo detoxification through the same processing methods, reflecting common underlying mechanisms. Investigating such shared mechanisms across multiple species of the same genus offers a promising research strategy. Ultimately, the research into processing-induced detoxification mechanisms provides both theoretical and practical support for ensuring the safety of toxic TCM.
Euphorbia/classification* ; Drugs, Chinese Herbal/metabolism* ; Humans ; Animals ; Inactivation, Metabolic ; Medicine, Chinese Traditional