Antiviral Drugs Lamivudine Research Articles

Comparative study of UV spectroscopy, RP-HPLC and HPTLC methods for quantification of antiviral drug lamivudine in tablet formulation

BackgroundIn the current study, estimation of lamivudine (LMU) by UV spectroscopy, reverse-phase HPLC (RP-HPLC) and HPTLC methods in tablet formulation was developed, and comparative studies between the methods were investigated by analytical results and statistical test analysis of variance (ANOVA) to find out best method. In the UV spectral method, LMU was quantified at 271 nm absorption maxima using methanol as the solvent. In the RP-HPLC method, the Shimadzu C18 column (250 mm × 4.6 mm i.d., 5 µm particle size) was employed for chromatographic separation. The mobile phase used consists of methanol: water (70:30 v/v) in an isocratic mode with a 1.0 mL/min flow rate. In the HPTLC method, the chromatogram was developed on a pre-coated plate of silica gel 60 F254 with a mobile phase composition of chloroform: methanol (8:2 v/v). The quantification was performed at an absorbance mode of 271 nm by densitometry. The methods were validated according to the International Conference on Harmonization (ICH) guideline Q2 (R1). The degradation conditions were employed as per ICH guidelines Q1A(R2) and Q1B which include acid, alkaline, neutral, thermal and photostability to determine the intrinsic stability of the drug in varied environmental conditions.ResultsLMU absorption maxima was found to be 271 nm. The retention time of LMU was 3.125 min, and the total analysis time was 5 min. The Rf value of LMU was 0.49–0.62. The methods were linear within 2–12 μg/mL range. The correlation coefficient (r2) for UV, HPLC and HPTLC was 0.9980, 0.9993 and 0.9988, and percent recoveries were calculated as 98.40–100.52%, 99.27–101.18% and 98.01–100.30%, respectively, with percentage relative standard deviation (RSD) less than 2% showing that methods were precise and accurate.ConclusionDeveloped UV, RP-HPLC and HPTLC methods are free from intervention caused by excipients present in tablets and thus can be used for regular quantitative analysis of LMU in tablet formulation. Based on analytical results and statistical tests, ANOVA, it is inferred that the HPLC method is best for LMU quantification tablet formulation due to its high reproducibility, good retention time and sensitivity; it has a higher percent recovery and has less analysis time, i.e., 5 min. The degradation peaks were well separated from the LMU peak indicating stability of the HPLC method.

Highly dispersed Cu and Ni nano cluster sensor for ultrasensitive electrochemical detection of antiviral drug lamivudine.

The accurate and rapid detection for the nucleoside reverse transcriptase inhibitor lamivudine (LAM, 3TC) in cellular systems is always a challenge in the clinic application. Here, a sensitive Cu and Ni nano cluster sensor for LAM is generated underhydrothermal conditions.TheCu and Ni atoms are highly dispersed and aggregated in the nanosized opening pore windows of the synthesized LTA zeolite, through the diatomic synergistic contribution of Cu and Ni and the enrichment of zeolitic channel pores. Using differential pulse voltammetry (DPV), the detection limit (LOD) of LAM at the potential (- 0.15V) can reach 0.001pM and the linear range is 0.002pM-0.002μM. Since the nano cluster is separated and restricted by the nanosized windows of the zeolite framework, the sensor provideshigh stability, good recovery (92.5-109%) and RSD (0.8-3.2%) in the analysis oftap water, RPMI 1640 medium, and rabbit serum. The Cu/Ni/LTA zeolite-modified glassy carbon electrode (Cu/Ni/LTA/GCE) exhibits excellent catalytic performance for LAM with high selectivity over potentiallyinterfering agents. A sensitive Cu and Ni nano cluster sensor for LAM is generated in the hydrothermal condition that the Cu and Ni atoms are highly dispersed and aggregated in the nanosized opening pore windows of the as-synthesized LTA zeolite. Through the diatomic synergistic contribution of Cu and Ni and the enrichment of zeolitic channel pores, the observed limit of detection (LOD) can reach 0.001 pM under differential pulse voltammetry (DPV) method with a wide linear relationship to 0.002 μM.

Amplifying anti-flooding electrode to fabricate modular electro-fenton system for degradation of antiviral drug lamivudine in wastewater

The advanced oxidation based on in-situ hydrogen peroxide production using carbon air cathode is very potential for wastewater treatment. However, catalyst flooding and complex assembly patterns are the bottleneck limiting the air cathode to the long-term and large-scale application. In this work, a novel anti-flooding air-breathing cathode (ABC) was prepared by a simple rolling-spraying method with relatively low price commercial materials. The novel method changed the morphology of gas diffusion layer as well as adjusted the hydrophobicity of air side of the catalyst layer. As a result, water-air distribution management was achieved and TPI disequilibrium was prevented. Compare with traditional ABC, the H2O2 yield and current efficiency (CE) of optimized anti-flooding ABC (ABC0.9) increased by 13.5% (941 ± 10 mg·L−1·h−1 with CE of 84% at 30 mA·cm−2), the material cost and fabrication time decreased by 10.1% (2.32 ¥·dm−2, ~0.36 $·dm−2) and 40%. Amplified ABC coupled with Ti/IrO2 anodes were integrated into a modular electrode used for H2O2generation. When the current density (j) increased from 10 to 30 mA·cm−2, the energy cost increased from 0.19 to 0.43 ¥·mol−1 H2O2 (from 0.03 to 0.07 $·mol−1 H2O2). The modular electrode was utilized in a 2 L pre-pilot scale reactor for antiviral drug lamivudine degradation by electro-Fenton (EF) process. 100% of lamivudine and 78.1% of total organic carbon (TOC) were removed within 60 min at 20 mA·cm−2. The susceptible sites on the lamivudine toward hydroxyl radicals were investigated and transformation products (TP) as well as degradation pathway were studied.

Electrochemical degradation of antivirus drug lamivudine formulation: photoelectrocoagulation, peroxi-electrocoagulation, and peroxi-photoelectrocoagulation processes

This study evaluates the performance of photoelectrocoagulation, peroxi-electrocoagulation, and peroxi-photoelectrocoagulation for the removal of the antiviral drug lamivudine formulation from wastewater by a stainless-steel electrode. To investigate matrix effects for this oxidation process, the influence of substrates such as urea and simulated wastewater (SWW) was studied. Moreover, degradation kinetics and energy efficiency are also discussed. Results indicate that the removal efficiency was in the order of peroxi-photoelectrocoagulation > peroxi-photoelectrocoagulation (in the presence of urea) > peroxi-photoelectrocoagulation (in the presence of SWW) > peroxi-electrocoagulation > photoelectrocoagulation. In peroxi-photoelectrocoagulation, the 96% degradation of lamivudine formulation indicates a nearly complete degradation of lamivudine. In this process, the presence of urea and SWW resulted in a substantial reduction of chemical oxygen demand (COD) decay. Kinetic studies using linear pseudo-first and pseudo-second-order reaction kinetics showed that the pseudo-first-order equation effectively described the removal of lamivudine formulation. The highest energy consumption per kgCOD decay (i.e., kWh kgCOD− 1) was obtained for the photoelectrocoagulation process, while the lowest energy consumption was obtained for peroxi-electrocoagulation, for all electrolysis times. The peroxi-photoelectrocoagulation process was shown to be an effective and energy-efficient technique for removing the antiviral drug lamivudine formulation from wastewater.

Synthesis, characterization, cytotoxicity and DNA binding studies of Fe3O4@SiO2 nanoparticles coated by an antiviral drug lamivudine

Chemically, lamivudine is amino-1-[(2R,5S)-2-(hydroxymethyl)-4,1,3-oxathiolan-5-yl]-1,2-dihydropyrimidin-2-one, that commonly named 3TC, is a water soluble potent nucleoside analog reverse transcriptase inhibitor. The present protocol reports the covering of silica on the surface of Fe3O4 nanoparticles (NPs) using Stöber method via sol-gel process and preparation of magnetic Fe3O4@SiO2-lamivudine NPs via chemical co-precipitation procedure. The structural features of Fe3O4@SiO2-3TC NPs were characterized by FT-IR spectroscopy, TEM, FESEM, Zetasizer and TGA analyzer, observations. The obtained results from structural analysis clearly indicate the core-shell array with average sizes of 30 nm for Fe3O4@SiO2-3TC NPs. The in vitro cytotoxic activity of Fe3O4@SiO2-3TC NPs was explored against AGS and MCF-7 cancer cell lines in comparison with lamivudine using LDH colorimetric assay and differential staining cell death assay (Hoechst/Propodium Ioide). Achieved results revealed that the influences of Fe3O4@SiO2-3TC NPs on the cell lines were nearly two orders of magnitude higher than that of lamivudine. Furthermore, the spectroscopic methods proved that DNA used groove binding mode for aggregated on Fe3O4@SiO2-3TC NPs.

Structural Insights into the Post-Chemistry Steps of Nucleotide Incorporation Catalyzed by a DNA Polymerase.

DNA polymerases are essential enzymes that faithfully and efficiently replicate genomic information.1-3 The mechanism of nucleotide incorporation by DNA polymerases has been extensively studied structurally and kinetically, but several key steps following phosphodiester bond formation remain structurally uncharacterized due to utilization of natural nucleotides. It is thought that the release of pyrophosphate (PPi) triggers reverse conformational changes in a polymerase in order to complete a full catalytic cycle as well as prepare for DNA translocation and subsequent incorporation events. Here, by using the triphosphates of chain-terminating antiviral drugs lamivudine ((-)3TC-TP) and emtricitabine ((-)FTC-TP), we structurally reveal the correct sequence of post-chemistry steps during nucleotide incorporation by human DNA polymerase β (hPolβ) and provide a structural basis for PPi release. These post-catalytic structures reveal hPolβ in an open conformation with PPi bound in the active site, thereby strongly suggesting that the reverse conformational changes occur prior to PPi release. The results also help to refine the role of the newly discovered third divalent metal ion for DNA polymerase-catalyzed nucleotide incorporation. Furthermore, a post-chemistry structure of hPolβ in the open conformation, following incorporation of (-)3TC-MP, with a second (-)3TC-TP molecule bound to the active site in the absence of PPi, suggests that nucleotide binding stimulates PPi dissociation and occurs before polymerase translocation. Our structural characterization defines the order of the elusive post-chemistry steps in the canonical mechanism of a DNA polymerase.

Engineering of glycyrrhizin capped gold nanoparticles for liver targeting: in vitro evaluation and in vivo biodistribution study

Glycyrrhizin reduced and stabilized gold nanoparticles as carriers of antiviral drug lamivudine. The presence of glycyrrhizin enhanced uptake and localization of drug loaded gold nanoparticles in hepatocytes.

Vibrational spectroscopic study of polymorphism and polymorphic transformation of the anti-viral drug lamivudine

Vibrational spectra of hydrated and anhydrous lamivudines, and also the dynamic process of polymorphic transformation have been characterized by Fourier transform infrared (FT-IR) and Raman spectroscopic techniques. The vibrational modes of both polymorphic lamivudines are assigned. FT-IR and Raman spectral results show that the interaction between crystalline water and lamivudine molecular has an important effect on the molecular vibration motions of polymorphic lamivudines. The two characteristic Raman peaks at 783 and 798cm−1 represent hydrated and anhydrous lamivudine respectively. The relationship between changes of two characteristic peak normalized areas and heating time could be fitted with single exponential functions, and the dynamic information of polymorphic transformation of lamivudine drug is obtained. The decay rate of characteristic peak for hydrated lamivudine and the growth rate of that for anhydrous lamivudine are consistent during dehydration transformation process. The reported results provide us important benchmark for qualitatively monitoring different polymorphic drugs and also establishing the corresponding model for the polymorphic transformation of drugs in related pharmaceutical research fields.

Impact of Drug-Resistance Polymerase Mutations on the Replication of HBeAg-Positive and HBeAg-Negative Hepatitis B Virus Strains in Vitro

Impact of Drug-Resistance Polymerase Mutations on the Replication of HBeAg-Positive and HBeAg-Negative Hepatitis B Virus Strains in Vitro

Treatment of Hepatitis B Virus-Associated Membranous Nephropathy: Lamivudine Era versus Post-Lamivudine Era

Treatment of Hepatitis B Virus-Associated Membranous Nephropathy: Lamivudine Era versus Post-Lamivudine Era

Interaction of Calf Thymus DNA with the Antiviral Drug Lamivudine

One approach to accelerate the availability of new cancer drugs is to test drugs approved for other conditions as anticancer agents. In recent years, some researchers have shown that antiviral drugs, such as ritonavir, saquinavir, and nelfinavir, inhibit the growth of over 60 cancer cell lines derived from nine different tumor types. This article studied the anticancer potential of an antiviral drug, lamivudine (LA). The interaction of LA and calf thymus DNA (CT-DNA) was studied using emission, absorption, circular dichroism (CD), and viscosity techniques. The binding constants evaluated from fluorescence data at different temperatures revealed that fluorescence enhancement is a static process that involves complex-DNA formation in the ground state. Further, the enthalpy and entropy of the reaction between the drug and CT-DNA showed ΔH<0 (-126.38±0.61 kJ mol(-1)) and ΔS<0 (-352.17±2.1 J mol(-1) K(-1)); therefore, van der Waals interactions or hydrogen bonds are the main forces in the binding of LA to CT-DNA. The values of K(f) clearly underscore the high affinity of LA to DNA. In addition, detectable changes in the CD spectrum of CT-DNA in the presence of LA indicated conformational changes. All these results showed that groove binding is the binding mode of this drug and CT-DNA.

Hepatitis B virus reactivation in association with antineoplastic therapy

Hepatitis B virus (HBV) is a major cause of chronic liver disease worldwide. HBV reactivation with immunosuppressive treatments is thoroughly described, and is most widely reported in patients who have chronic HBV infection, when hepatitis B surface antigen (HBsAg) is positive, in connection with chemotherapy used to treat lymphoma. However, reactivation can also occur in patients who have prior resolved HBV infection, in whom HBsAg is negative but antibody to hepatitis B core antigen is positive. The antiviral drug lamivudine is highly efficacious in preventing HBV reactivation in these circumstances.

Investigation into classification/sourcing of suspect counterfeit Heptodin™ tablets by near infrared chemical imaging

Near infrared chemical imaging (NIR-CI) analysis was performed on 55 counterfeit Heptodin™ tablets obtained from a market survey and an additional 11 authentic Heptodin™ tablets for comparison. The aim of the study was to investigate whether NIR-CI can be used to detect the counterfeit tablets and to classify/source them so as to understand the possible number of origins to aid investigators and authorities to shut down counterfeiting operations. NIR-CI combined with multivariate analysis is particularly suited to compare chemical and physical properties of samples, since it is a quick and non-destructive method of analysis. Counterfeit tablets were easily distinguished from the authentic ones. Principal component analysis (PCA) and k-means clustering were performed on the data set. The results from both analyses grouped the counterfeit tablets in 13 main groups. The main groups found with both methods were quite consistent. Out of the 55 tablets only 18% contained the correct active pharmaceutical ingredient (API), i.e., the anti-viral drug lamivudine. The remaining 82% of counterfeit tablets contained talc and starch as main excipients. The API containing tablets classified into three main groups, based mainly on the amount of lamivudine present in the tablet. The group which had close to the correct amount of lamivudine sub-classified into three groups. From the analysis carried out, it is likely that the counterfeit tablets originate from as many as 15 different sources.

Synthesis, Analysis, in Vitro Characterization, and in Vivo Disposition of a Lamivudine–Dextran Conjugate for Selective Antiviral Delivery to the Liver

A liver-selective prodrug (3TCSD) of the antiviral drug lamivudine (3TC) was developed and characterized. 3TC was coupled to dextran ( approximately 25 kDa) using a succinate linker, and the in vitro and in vivo behavior of the conjugate was studied using newly developed size-exclusion and reversed-phase analytical methods. Synthesized 3TCSD had a purity of >99% with a degree of substitution of 6.5 mg of 3TC per 100 mg of the conjugate. Furthermore, the developed assays were precise and accurate in the concentration ranges of 0.125-20, 0.36-18, and 1-50 microg/mL for 3TC, 3TC succinate (3TCS), and 3TCSD, respectively. In vitro, the conjugate slowly released 3TC in the presence of rat liver lysosomes, whereas it was stable in the corresponding buffer. In vivo in rats, conjugation of 3TC to dextran resulted in 40- and 7-fold decreases in the clearance and volume of distribution of the drug, respectively. However, the accumulation of the conjugated 3TC in the liver was 50-fold higher than that of the parent drug. The high accumulation of the conjugate in the liver was associated with a gradual and sustained release of 3TC in the liver. These studies indicate the feasibility of the synthesis of 3TCS-dextran and its potential use for the selective delivery of 3TC to the liver.

Treatment of chronic hepatitis B with lamivudine.

To study the efficacy of antiviral drug lamivudine for treatment of chronic hepatitis B in Pakistani population. Experimental study. A tertiary Care Center, from January 2000 to January 2004. Patients who had positive hepatitis B surface antigen (HBsAg) and elevated ALT were recruited. Both hepatitis Be antigen (HBeAg) positive and HBeAg negative patients were included. Treatment was given with lamivudine 100mg once a day for 12 months and they were followed every 2-3 months with ALT, HBeAg, and in certain cases with, HBV DNA (PCR). Those patients who were HBeAg positive were considered to have achieved end of treatment response (ETR) when ALT was normal and HBeAg was negative and this was documented at two consecutive occasions, at least one month apart. Those patients who were HBeAg negative were considered to have achieved ETR when their ALT was normal and HBV DNA was undetectable. Patients were followed for further 6 months to evaluate for any relapse. A total of 105 patients were included. Eighty-two (78.1%) were males and 23 (21.9%) were females. Mean ALT of all patients was 87.15 +/- 46.01 u/dl. Seventy-two HBeAg positive and 15 HBeAg negative patients completed treatment with 23.6 % and 80.0 % response rate respectively (p <0.001). The response of lamivudine in chronic hepatitis B in Pakistani population is encouraging in HBeAg negative patients but is rather low in those who are HBeAg positive.