3D printed tinidazole tablets coupled with melt-extrusion techniques for formulating child friendly medicines.

This study investigates the feasibility of fabrication of poly(1-vinyl-2-pyrrolidone) (Kollidon®25)-mediated filaments for producing tinidazole (TNZ)-loaded, customizable, child-friendly tablets (with varying shapes and sizes) using hot melt extrusion (HME) coupled with fused deposition modeling (FDM) technology. Kollidon®25, chosen for its ability to enhance the dissolution of TNZ (a BCS Class II drug), was evaluated for polymer-drug compatibility through Hansen solubility, polarity, and interaction parameter analyses, confirming good miscibility and affinity between TNZ and Kollidon®25. Placebo- and TNZ-loaded filaments were prepared in different ratios using HME, followed by the development of 3D-printed tablets via FDM. The fabricated batches of placebo and TNZ-loaded 3D tablets were characterized, and it was found that they had an average weight variation of 270.41 ± 7.44 mg and 270.87 ± 9.33 mg, hardness of 155.01 ± 11.79 N and 265.3 ± 7.62 N, and friability of 0.1583 ± 0.0011 % and 0.2254 ± 0.0013 %. Amorphization was confirmed by differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD) analysis. Scanning electron microscopy (SEM) revealed a layer-by-layer pattern with tiny fractures on the tablet surfaces, which enhanced media penetration, resulting in improved dissolution profiles. The TNZ release profile showed complete 100 % release within 2.0 h in a gastric acidic medium. These findings support the potential of Kollidon®25 to create customizable, child-friendly, 3D-printed dosage forms with different shapes and sizes for TNZ delivery, offering a unique approach to paediatric medications.

Ca-doped ZnO nanoparticles for MB dye degradation and adsorptive removal of tinidazole.

Industrial dye degradation involves several processes by which dyes are broken down, ideally into innocuous products. Methylene blue (MB) is one of the most commonly employed dyes in the textile industry and is released into water in routine industry processes. These discharges lead to creating a nocuous nature for humans and animals. Drugs are also discharged into water bodies from various pharmaceutical industries. In these two contexts, in the present work, the green synthesis of calcium-doped zinc oxide nanoparticles (Ca-doped ZnO NPs) is achieved using the aqueous peel extract of Citrus limetta by the solution combustion technique. The structural, morphological, and optical properties of the synthesized Ca-doped ZnO NPs are investigated using XRD, FTIR, SEM, EDX, and UV-visible spectroscopy. The prepared NPs were subjected to photocatalytic degradation of MB dye under visible-light illumination, which shows ~ 95% dye degradation. The synthesized Ca-doped ZnO NPs were also employed to adsorb tinidazole (TDZ), a nitroimidazole antibiotic, from water samples. An excellent adsorptive capacity of the NPs was observed for selectively adsorbing the TDZ ~ 96.2%. The drug TDZ was found to have pseudo-second-order kinetics. The catalyst recycling proved its repeatability; removal of the dye reached up to 92% after three successive usages. Therefore, using waste Citrus limetta peel extract, the multifunctional Ca-doped ZnO NPs were synthesized, which maintained effective adsorption potential and photocatalytic abilities and could be used as an effective material for environmental remediation.

Specific Anti-biofilm Activity of Carbon Quantum Dots by Destroying P. gingivalis Biofilm Related Genes.

INTRODUCTION: Biofilms protect bacteria from antibiotics and this can produce drug-resistant strains, especially the main pathogen of periodontitis, Porphyromonas gingivalis. Carbon quantum dots with various biomedical properties are considered to have great application potential in antibacterial and anti-biofilm treatment. METHODS: Tinidazole carbon quantum dots (TCDs) and metronidazole carbon quantum dots (MCDs) were prepared by a hydrothermal method with the clinical antibacterial drugs tinidazole and metronidazole, respectively. Then, TCDs and MCDs were characterized by transmission electron microscopy, UV-visible spectroscopy, infrared spectroscopy and energy-dispersive spectrometry. The antibacterial effects were also investigated under different conditions. RESULTS: The TCDs and MCDs had uniform sizes. The results of UV-visible and energy-dispersive spectrometry confirmed their important carbon polymerization structures and the activity of the nitro group, which had an evident inhibitory effect on P. gingivalis, but almost no effect on other bacteria, including Escherichia coli, Staphylococcus aureus and Prevotella nigrescens. Importantly, the TCDs could penetrate the biofilms to further effectively inhibit the growth of P. gingivalis under the biofilms. Furthermore, it was found that the antibacterial effect of TCDs lies in its ability to impair toxicity by inhibiting the major virulence factors and related genes involved in the biofilm formation of P. gingivalis, thus affecting the self-assembly of biofilm-related proteins. CONCLUSION: The findings demonstrate a promising new method for improving the efficiency of periodontitis treatment by penetrating the P. gingivalis biofilm with preparations of nano-level antibacterial drugs.

Molecular dynamics simulation of the adsorption behavior of two different drugs on hydroxyapatite and Zn-doped hydroxyapatite.

Hydroxyapatite (HAp) is a highly promising material as a drug carrier. The solubility, osteoinductivity, antibacterial properties and drug loading efficiency of HAp can be further enhanced by Zn doping. In this study, we carried out first-principles and molecular dynamics (MD) simulations to investigate the influence of Zn doping on the crystal structure and adsorption capacity of macromolecular drugs on HAp. Our results showed that the binding energy of doxorubicin (DOX) on HAp is significantly increased in consequence of Zn-doping. Moreover, the interaction between surface Ca ions and carbonyl-O mostly contributed to the adsorption. The binding energy of tinidazole on HAp was much lower than that observed for DOX. The number of active "O" atoms in the drug and binding stability were positively correlated. These simulations provide important insight into the understanding of drug adsorption on HAp or ion-doped HAp.

Effect of Drug Combination on Omeprazole Metabolism by Cytochrome P450 2C19 in Helicobacter pylori Eradication Therapy.

Helicobacter pylori (H. pylori) infection is common and can result in gastric and duodenal ulcers, and in some cases, gastric lymphoma and cancer. Omeprazole (OMP)-in combination with clarithromycin (CLR), amoxicillin (AMX), tinidazole (TND), or metronidazole (MET)-is used in double or triple combination therapy for eradication of H. pylori. However, the roles of the drugs other than OMP are not clearly understood. Therefore, in the present study, we aimed to investigate any effects of these drugs on OMP metabolism by wild-type CYP2C19 using spectroscopy and enzyme kinetics. The dissociation constants (Kd) for CYP2C19 with OMP, CLR, AMX, TND, and MET were 8.6, 126, 156, 174, and 249 µM, respectively. The intrinsic clearance of OMP was determined to be 355 mL/min/µmol of CYP2C19. Metabolism of OMP was significantly inhibited by 69, 66, 28, and 40% in the presence of CLR, TND, AMX, and MET, respectively. Moreover, the combination of CLR and TND resulted in 76% inhibition of OMP metabolism, while the combination of AMX and MET resulted in 48% inhibition of OMP metabolism. Both combinations of drugs not only have antibacterial effects, but also enhance the effect of OMP by inhibiting its metabolism by CYP2C19. These results indicate that drug-drug interactions of co-administered drugs can cause complex effects, providing a basis for OMP dose adjustment when used in combination therapy for H. pylori eradication.

Fabrication and evaluation of dental fillers using customized molds via 3D printing technology.

In view of the high incidence and long-term treatment of dental caries, personalized dental fillers with long therapeutic action have broad application prospects in the dental clinic. The objective of this study was to fabricate and evaluate novel dental fillers using state-of-the-art 3D printing technology. Tinidazole (TNZ), a commonly used antibacterial drug in the dental clinic, was chosen as the model compound. Models of molars with carious cavities were obtained via 3D scanning. TNZ dental fillers were indirectly produced by thermal pressing using customized 3D printed molds. In addition, bio-relevant in vitro dissolution and mechanical testing methods were developed using customized 3D printed release and compression molds, respectively. It was observed that the formability, mechanical properties, and release behavior of the TNZ dental fillers were affected by mold materials, plasticizers, and release modifiers. The developed dental fillers were capable of sustained releasing TNZ over one week. The TNZ release characteristics can be tailored based on clinical requirements by varying hydroxypropyl methylcellulose E5 (HPMC-E5) concentrations and filler dimensions. Moreover, computational simulation based on the finite element method showed that the biomechanical behavior of the TNZ dental fillers met the daily use requirement. The present study demonstrated that the state-of-the-art 3D printing technology can be used to design and fabricate personalized dental fillers with high mechanical strength and "on-demand" drug release characteristics.

Controlled delivery of the antiprotozoal agent (tinidazole) from intravaginal polymer matrices for treatment of the sexually transmitted infection, trichomoniasis.

Microporous polymeric matrices prepared from poly(ɛ-caprolactone) [PCL] were evaluated for controlled vaginal delivery of the antiprotozoal agent (tinidazole) in the treatment of the sexually transmitted infection, trichomoniasis. The matrices were produced by rapidly cooling co-solutions of PCL and tinidazole in acetone to -80 °C to induce crystallisation and hardening of the polymer. Tinidazole incorporation in the matrices increased from 1.4 to 3.9% (w/w), when the drug concentration in the starting PCL solution was raised from 10 to 20% (w/w), giving rise to drug loading efficiencies up to 20%. Rapid 'burst release' of 30% of the tinidazole content was recorded over 24 h when the PCL matrices were immersed in simulated vaginal fluid. Gradual drug release occurred over the next 6 days resulting in delivery of around 50% of the tinidazole load by day 7 with the released drug retaining antiprotozoal activity at levels almost 50% that of the 'non-formulated' drug in solution form. Basic modelling predicted that the concentration of tinidazole released into vaginal fluid in vivo from a PCL matrix in the form of an intravaginal ring would exceed the minimum inhibitory concentration against Trichomonas vaginalis. These findings recommend further investigation of PCL matrices as intravaginal devices for controlled delivery of antiprotozoal agents in the treatment and prevention of sexually transmitted infections.

HPTLC method for Simultaneous Determination of Norfloxacin and Tinidazole in presence of Tinidazole Impurity.

Sensitive, selective and accurate high-performance thin layer chromatographic HPTLC method for quantitative determination of Norfloxacin (NF), Tinidazole (TZ) and 2-Methyl-5-nitroimidazole (MNZ) as potential impurity of Tinidazole is developed and validated in the presented work. Calibration curves were linear over the concentration ranges of 0.4-2.4, 0.4-1.6, 0.2-1.2 µg/band for NF, TZ and MNZ, respectively. The method depends on separation and quantitation of NF, TZ and MNZ on aluminium plates pre-coated with silica gel HPTLC 60F254 as stationary-phase using chloroform: methanol: formic acid (7.5:1: 0.3, by volume) as developing system followed by densitometric measurement of bands at 298 nm. The developed method was validated and proved to meet the requirements delineated by ICH guidelines with respect to linearity, accuracy, precision, specificity and robustness. The validated method was successfully applied for determination of studied drugs in bulk powders and in their pharmaceutical formulation indicating the ability of proposed method to be used for routine quality control analysis of these drugs.

Sensitive inexpensive chromatographic determination of an antimicrobial combination in human plasma and its pharmacokinetic application.

This study represents simple inexpensive chromatographic determination of ciprofloxacin (CIP) and tinidazole (TIN) simultaneously in human plasma using HPLC-DAD followed by a pharmacokinetic application. C18 column was used as stationary phase with isocratic elution of a mobile phase composed of acetic acid solution (2%) and acetonitrile (85: 15, v/v) and ornidazole as internal standard (IS) with UV detection at 318 nm. The two drugs and the IS were separated at 6.55, 7.91 and 11.07 min for CIP, TIN and IS, respectively, with good selectivity and sensitivity for their analysis in presence of plasma matrix components and the drugs' metabolites. Sample preparation involved only protein precipitation without any complicated extraction procedures decreasing analysis time. For method validation, FDA regulations for analysis in biological fluids were followed. Pharmacokinetic (PK) study on six healthy volunteers was conducted after single oral dose administration of 500 and 600 mg of CIP and TIN, respectively. Dugs' plasma levels were followed for 12 or 72 h post dosing for CIP and TIN, respectively, and different PK data for the two drugs were calculated and they were comparable to the reported values demonstrating successful future application of the presented method in PK, bioequivalence and bioavailability studies.

DNA interactions of non-chelating tinidazole-based coordination compounds and their structural, redox and cytotoxic properties.

Novel tinidazole (tnz) coordination compounds of different geometries were synthesised, whose respective solid-state packing appears to be driven by inter- and intramolecular lone pairπ interactions. The copper(ii) compounds exhibit interesting redox properties originating from both the tnz and the metal ions. These complexes interact with DNA through two distinct ways, namely via electrostatic interactions or/and groove binding, and they can mediate the generation of ROS that damage the biomolecule. Cytotoxic studies revealed an interesting activity of the dinuclear compound [Cu(tnz)2(µ-Cl)Cl]27, which is further more efficient towards cancer cells, compared with normal cells.

Formulation and solid state characterization of carboxylic acid-based co-crystals of tinidazole: An approach to enhance solubility.

BACKGROUND: Tinidazole (TNZ) is an anti-parasite drug used in the treatment of a variety of amebic and parasitic infections. It has low solubility in aqueous media and is categorized under Class II of the Biopharmaceutical Classification System. OBJECTIVES: The aim of this research was to study the potential for enhancing the solubility of TNZ using carboxylic acid co-crystals. MATERIAL AND METHODS: The solubility of TNZ was determined individually using 6 carboxylic acids for forming co-crystals at a 1:1 stoichiometric ratio. Three carboxylic acids - namely tartaric acid (TA), oxalic acid (OA) and glutaric acid (GA) - resulted in the formation of co-crystals with enhanced solubility. An equilibrium solubility study of TNZ co-crystals at 1:1.5 and 1:2 stoichiometric ratios was also carried out. The co-crystals which developed were evaluated using X-ray powder diffraction (XRD) and differential scanning calorimetry (DSC) to study the drug-co-crystal former interactions. RESULTS: The solubility of TNZ in distilled water was found to be 0.014 mg/mL. The highest enhancement ratio was obtained with TNZ and TA at a ratio of 1:1. Differential scanning calorimetry thermograms suggested that the drug and carboxylic acids had undergone interactions such as hydrogen bonding. The XRD and DSC results confirmed the formation of co-crystals. CONCLUSIONS: It was concluded that the results of enhanced solubility of TNZ using co-crystals is a clear indication of the potential for co-crystals to be used in the future for other poorly water-soluble drugs, considering that co-crystals are a safe and cost-effective approach.

Novel antihelmintic activity of tinidazole coordination compounds. Relevance of the metal ion and structural properties.

The in vitro and in vivo antihelmintic activity of cobalt(II), copper(II) and zinc(II) coordination compounds of tinidazole (tnz) were investigated in cultivated spotted rose snapper, infested with dactylogyrid monogeneans. The tinidazole coordination compounds [Co(tnz)2Cl2], [Co(tnz)2Br2], [Cu(tnz)2Cl2], [Cu(tnz)2Br2], [Zn(tnz)2Cl2] and [Zn(tnz)2Br2] were synthesized and spectroscopically characterized. Their molecular structures were determined by their single crystal X-ray diffraction. The metal ions presented distorted tetrahedral geometries, with an intramolecular bifurcated lone pair SO⋯π, from the sulfone group with the imidazolic ring, which contributed to the stability of the compounds in solid state and in solution. Adults of dactylogyrids were exposed in vitro to tinidazole and its coordination compounds. The effective median concentrations of copper(II) coordination compounds were lower than those of cobalt(II) and zinc(II), tnz showed no activity. In vivo oral intubation tests were carried out with [Cu(tnz)2Br2], [Zn(tnz)2Br2] and tnz on snappers infected with dactylogyrids, where the copper(II) compound showed better activity. The absorption and distribution assessment for the [Cu(tnz)2Br2], showed that copper concentrations in liver were significantly higher than in blood and gills, indicating bioaccumulation in this organ. In vivo baths of [Cu(tnz)2Br2] at 25mg/L showed an effective (95% at 8h) antihelmintic effect, while [Zn(tnz)2Br2] had low antihelmintic efficacy. This study indicates that [Cu(tnz)2Br2] has an effective antihelmintic activity towards dactylogyrids monogeneans affecting cultivated spotted red snapper.

Tinidazole functionalized homogeneous electrospun chitosan/poly (ε-caprolactone) hybrid nanofiber membrane: Development, optimization and its clinical implications.

We have prepared tinidazole (TNZ) functionalized biodegradable chitosan (CH)/poly (ε-caprolactone) (PCL) mucoadhesive hybrid nanofiber membrane (TNZ-PCHNF) to alleviate existing shortcomings in treatment of periodontitis. Box-Behnken design was employed for evaluating influence of formulation and processing variables on quality of final formulation. Optimized nanofiber membrane was subjected to solid-state and surface characterization studies using FTIR, DSC, XRD, SEM and AFM, which revealed that TNZ was entrapped in an amorphous form inside smooth and uniform cylindrical nanofibers without any physicochemical interaction with excipients. The optimized TNZ-PCHNF membrane had a diameter of 143.55±8.5nm and entrapment efficiency of 83.25±1.8%. In vitro drug release and antibacterial study demonstrated capability of the developed nanofiber membranes for efficiently delivering TNZ in a sustained manner up to 18days, and its ability to inhibit bacterial growth, respectively. Further, reduction of contact angle (from 123.4±2.5 to 27.4±2.3) revealed that blending of CH with PCL increases hydrophilicity of the nanofiber membrane. MTT assay and CLSM study suggested that nanofiber membrane was devoid of cytotoxicity on mouse fibroblasts. Moreover, preliminary clinical trials on patients proved therapeutic efficacy of the nanofiber membrane by eliciting a significant (p<0.05) decrease in clinical markers of periodontitis.

Synthesis, characterization and evaluation of tinidazole-loaded mPEG-PDLLA (10/90) in situ gel forming system for periodontitis treatment.

Traditional in situ gel forming systems are potential applications for parenteral administration but always accompanied with burst release. To overcome this limitation, the tinidazole (TNZ)-loaded in situ gel forming system using a diblock copolymer, monomethoxy poly(ethylene glycol)-block-poly(d,l-lactide) (mPEG-PDLLA), was designed. The formulation of the mPEG-PDLLA-based TNZ in situ gel forming system contained 5% (w/w) TNZ, 0.4% glycerol, 5 ml N-methyl pyrrolidone (NMP) and 35% (w/w) mPEG-PDLLA. The in situ gel forming system showed sustained TNZ release over 192 h with low burst effect (around 7% in the first 8 h) in the in vitro release study. Additionally, in vivo studies were performed on rabbits with ligature-induced periodontitis, and the concentration of TNZ in the gingival crevicular fluid (GCF) as well as the pharmacokinetic parameters was calculated and the pharmacological effect of TNZ-loaded in situ gel forming (mPEG-PDLLA)-based system was found effective. Finally, histological studies revealed that the gel was a safe formulation with low irritation. The desirable drug release kinetics combined with the excellent in vivo characteristics highlight the potential of the gel in the treatment of periodontitis. Therefore, these results confirmed that the TNZ-loaded in situ gel forming mPEG-PDLLA-based system could reduce burst release of TNZ and act as a sustained-release and injectable drug depot for periodontitis treatment.

Validated spectrophotometric methods for simultaneous determination of Omeprazole, Tinidazole and Doxycycline in their ternary mixture.

A comparative study of smart spectrophotometric techniques for the simultaneous determination of Omeprazole (OMP), Tinidazole (TIN) and Doxycycline (DOX) without prior separation steps is developed. These techniques consist of several consecutive steps utilizing zero/or ratio/or derivative spectra. The proposed techniques adopt nine simple different methods, namely direct spectrophotometry, dual wavelength, first derivative-zero crossing, amplitude factor, spectrum subtraction, ratio subtraction, derivative ratio-zero crossing, constant center, and successive derivative ratio method. The calibration graphs are linear over the concentration range of 1-20 µg/mL, 5-40 µg/mL and 2-30 µg/mL for OMP, TIN and DOX, respectively. These methods are tested by analyzing synthetic mixtures of the above drugs and successfully applied to commercial pharmaceutical preparation. The methods that are validated according to the ICH guidelines, accuracy, precision, and repeatability, were found to be within the acceptable limits.

Multiobjective optimization strategy based on desirability functions used for the microemulsion liquid chromatographic separation and quantification of norfloxacin and tinidazole in plasma and formulations.

The aim of the present study was to optimize a microemulsion liquid chromatography method for the simultaneous determination of norfloxacin and tinidazole binary mixture using a chemometric protocol. Optimization experiments were conducted through a process of screening and optimization. A 2(7-4) fractional factorial design was used as screening design. While the location of optimum conditions was established by applying Derringer's desirability function. The optimal mobile phase composition was predicted to be: 3.5% w/v SDS, 10.03% v/v 1-propanol, 0.5% v/v 1-octanol, and 0.3% triethylamine in 0.02 M phosphoric acid at pH 6.5. The mobile phase was delivered isocratically at a flow rate of 1 mL/min with UV detection at 290 nm. Tinidazole and norfloxacin were eluted with retention times of 1.8 and 5.8 min, respectively. The calibration plots displayed good linear relationships in the concentration ranges of 0.5-50 and 0.75-75 µg/mL for norfloxacin and tinidazole, respectively. The method was successfully applied for determination of both drugs in pharmaceutical dosage forms and real human plasma. Where the accuracy was proved by the low values of % error and high values of recovery, also the relative standard deviation for the results did not exceed 1.5%, proving the precision of the method.

Controlled release of tinidazole and theophylline from chitosan based composite hydrogels.

Several composite hydrogels were synthesized by free radical crosslink copolymerization of acrylic acid (AA) and N' methylene bis-acrylamide (MBA) in the presence of chitosan (CS). During polymerization CS was incorporated in situ in the crosslinked polyacrylic acid gel to produce composite hydrogels. The structure and properties of the hydrogels were characterized by FTIR, (13)C NMR, DTA-TGA, XRD, swelling and diffusion characteristic and also network parameters. The loading and the in vitro release behaviours of theophylline and tinidazole model drugs were studied with these hydrogels. The wt% of CS and MBA and pH of the medium was found to strongly influence the drug release behaviour of the gels. Accordingly, the release rate of these two drugs was much faster at pH of 7.6 than at pH 1.5.

Tinidazole removal from aqueous solution by sonolysis in the presence of hydrogen peroxide.

Aqueous solutions of the tinidazole (TNZ) have been treated by applying the combination of ultrasound irradiation and H2O2. Based on the results, the maximum removal efficiency of 75% was achieved under the optimum operating conditions (pH 3, 120 kHz frequency, 333 mM/L of H2O2 and 150 min of operating time) while, under the same conditions the minimum removal efficiency was found to be 8.5 by ultrasound radiation in the absence of H2O2. The results also revealed that the degradation of TNZ was enhanced with decreasing both TNZ initial concentrations and pH. Furthermore, TNZ removal efficiency in the case of actual wastewater was less than of synthetic wastewater (75% and 68% of synthetic and actual, respectively). According to the chromatographic analyses, no harmful intermediate compounds were observed. The chemical oxygen demand analysis (65% reduction) confirmed our findings.

Micellar HPLC and derivative spectrophotometric methods for the simultaneous determination of fluconazole and tinidazole in pharmaceuticals and biological fluids.

Micellar high-performance liquid chromatography (HPLC) and first-derivative ultraviolet spectrophotometry were used to simultaneously determine fluconazole (FLZ) and tinidazole (TNZ) in combined pharmaceutical dosage forms. The derivative procedure is based on the linear relationship between the drug concentration and the first derivative amplitudes at 220 and 288 nm for FLZ and TNZ, respectively. The calibration graphs were linear in the range of 1.5-9.0 µg/mL for FLZ and 10.0-60.0 µg/mL for TNZ. Furthermore, an HPLC procedure with ultraviolet detection at 210 nm was developed. For the HPLC procedure, good chromatographic separation was achieved using an ODS C18 column (250 × 4.6 mm i.d.). The mobile phase containing 0.15M sodium dodecyl sulphate, 0.3% triethylamine and 12% n-propanol in 0.02M orthophosphoric acid at pH 5.5 was pumped at a flow rate of 1 mL/min. Indapamide was used as an internal standard. The method showed good linearity over the concentration ranges of 1.5-30.0 and 10.0-200.0 µg/mL, with limits of detection of 0.36 and 2.70 µg/mL and limits of quantification of 1.1 and 8.2 µg/mL for FLZ and TNZ, respectively. The suggested methods were successfully applied for the simultaneous analysis of the drugs in their laboratory prepared mixture, co-formulated tablet and single dosage forms. Moreover the second method was also extended to the determination of the drugs in biological fluids.

A simple high-performance liquid chromatographic method for the determination of brazilin and its application to a pharmacokinetic study in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Caesalpinia sappan is a medicinal plant native to China popularly used to treat chronic pelvic inflammation, dysmenorrhea and hysteromyoma. Its main bioactive component is brazilin which had presented antibacterial, anti-inflammatory and anti-platelet aggregation activities. To establish a sensitive, selective, reproducible, and accurate high performance liquid chromatographic (HPLC) method for the quantitative determination of brazilin in plasma, and study the pharmacokinetics of brazilin in rats after intravenous administration of brazilin. MATERIALS AND METHODS: Rats received intravenous injection of 25, 50 and 100mg/kg of brazilin. Concentrations of brazilin in plasma were determined by HPLC method at different time points and all pharmacokinetic parameters were estimated by non-compartmental analysis with WinNonLin 6.2 software. RESULTS: After single intravenous doses of 25, 50 and 100mg/kg brazilin in rats, the main PK parameters were as follows: Cmax were 18.1 ± 4.1, 46.7 ± 8.7 and 82.2 ± 9.6 µg/mL; AUC0-24 were 20.4 ± 4.3, 48.7 ± 6.8 and 90.4 ± 10.3 µgh/mL; and t1/2 were 5.4 ± 1.5, 5.8 ± 0.9 and 6.2 ± 1.2h, respectively. CONCLUSION: It showed that the brazilin was eliminated moderately in rat by intravenous injection route with t1/2 of 6h and showed a dose-dependence profile of Cmax and AUC0-24 at the doses of 25~100mg/kg of brazilin for injection in rats.