Development and validation of a normal-phase HPTLC method for the simultaneous analysis of Lamivudine and Zidovudine in fixed-dose combination tablets

Bioequivalence and Pharmacokinetics Study of Two Zidovudine/Lamivudine Tablets in Chinese Healthy Volunteers

Zidovudine/lamivudine tablets are nucleoside reverse transcriptase inhibitors that are used to treat human immunodeficiency virus. The objective of this study was to investigate the bioequivalence and pharmacokinetics (PKs) of test and reference preparations of zidovudine/lamivudine tablets in healthy Chinese subjects. We designed a randomized, open, single-center, single-dose, 2-crossover experiment with a 7-day washout period involving 20 healthy subjects. The subjects were given a single dose of the test or reference preparation after fasting overnight for 10 hours. Blood samples were subsequently collected at scheduled time points from 0 hour (preadministration) up to 24 hours postadministration. The plasma concentrations of zidovudine and lamivudine were determined by a validated ultra-performance liquid chromatography-tandem mass spectrometry method. Analysis of variance (ANOVA) was used to compare differences in the mean values of key PK parameters between the 2 preparations. Bioequivalence was evaluated by 2 one-sided t-tests and 90% confidence intervals (CIs) of the geometric mean ratio (GMR). In total, 19 of the 20 subjects completed the trial. Based on the analysis of PK parameters, the relative bioavailability of zidovudine and lamivudine was 101.1% ± 2.0% and 100.3% ± 1.5%, respectively. ANOVA found no significant difference in primary PK parameters when compared between the 2 formulations, and the 90% CIs of the GMR of the 2 formulations were within the bioequivalence margins of 80%-125%. No serious adverse events occurred. Thus, we confirmed that the 2 preparations were bioequivalent in healthy Chinese volunteers. Our analysis demonstrated that both products showed good tolerance in all subjects.

Development of an anti-infective urinary catheter composed of polyvinyl alcohol/sodium alginate/methylcellulose/polyethylene glycol by using a pressure-assisted 3D-printing technique

Catheter-associated urinary tract infections (CAUTI) are a common complication associated with catheterization, leading to urosepsis, bacteriuria, and septicaemia. The present work focuses on 3D printing a urinary catheter with anti-infective properties using various concentrations of polyvinyl alcohol (PVA, e.g., 6-8 %), sodium alginate (NaAlg, e.g. 1-4 %), methylcellulose (MC, 5 %), polyethylene glycol (PEG, 5 %) impregnated with secnidazole, an antibiotic acting against Gram-negative bacteria. To produce suitable polymer ink for Pressure Assisted Microsyringe (PAM) 3D printing, the cross-linked between NaAlg and calcium chloride is necessary to prepare the catheter. The optimised catheter was found to have an outer diameter of 5 mm, an inner diameter of 3.5 mm, and a length of the catheter of 50 mm. The analysis by various methods confirms the successful incorporation of secnidazole in the 3D-printed catheter. A drug-loaded/coated catheter showed an initial drug release of 79 % following a sustained release to reach 100 % within 5 h. Weibull model fits well with the drug release data. The release models suggest the Quasi-Fickian diffusion mechanism from the system. Moreover, the secnidazole 3D printed catheter disrupted biofilms and suppressed all the Quorum sensing mediated virulence factors of two important keystone pathogens causing urinary tract infections.

Comparative application of derivative spectrophotometric and HPLC techniques for the simultaneous determination of lamivudine and tenofovir disoproxil fumarate in fixed-dose combined drugs

Background

Lamivudine (LAM) and tenofovir disoproxil fumarate (TDF) are part of a fixed-dose combination (FDC) therapy recommended by WHO. Both drugs exhibit similar solubility in many solvent systems and tend to have overlapping spectra with maxima at 260 and 270 nm, respectively, in the UV spectrum—thus making their spectrophotometric assay difficult in FDCs. A third-order derivative (D3, d3A/dλ3) spectrophotometric technique was applied to simultaneously evaluate TDF and LAM in FDC drugs, with amplitudes at 240 and 262.5 nm, respectively. Pharmacopoeia-recommended chromatographic method was also applied for comparative purpose.

Results

Method performance by the proposed D3 technique showed linearity for LAM and TDF from 2–10 µg mL−1 to 8–24 µg mL−1, respectively (R2 ≥ 0.998), while for HPLC method both drugs ranged from 0.25 to 5.0 µg mL−1 (R2 ≥ 0.999). The intercepts and slopes of the regression equations were ≤ 1.62 × 10−4 and ≤ 3.58 × 10−5, respectively, while calculated standard errors were ≤ 8.04 × 10−5. Limits of detection and quantification for both methods were ≤ 0.46 μg mL−1 and ≤ 1.40 μg mL−1, respectively, for LAM, while corresponding limits for TDF were ≤ 2.61 and ≤ 7.90 μg mL−1. The percentage recovery for both drugs and methods ranged from 94.80 to 100.33%. The amount of LAM and TDF in brands I and II was ≥ 99.59 ± 1.19% and ≥ 99.39 ± 0.63%, respectively, for the proposed D3 spectroscopic method, while corresponding values for the HPLC method were ≥ 99.86 ± 0.50 and ≥ 99.87 ± 0.32%. Statistically, both methods were adjudged to have no significant difference at 95% confidence level as the student’s t-test values; experimental paired t- and F-test values were found satisfactory.

Conclusion

The D3 spectrophotometric technique was time saving, cheap, simple and more environmental friendly and shows reliability, precision and accuracy and could be used for routine analysis of FDCs where HPLC is not available.

Graphical abstract

A new stability indicating RP-UPLC method for simultaneous estimation of Doravirine, Lamivudine and Tenofovir disoproxil fumarate in bulk and their combined pharmaceutical formulation

Background

To establish a simple, sensitive, accurate, precise, efficient, economical RP-UPLC method for simultaneous estimation of Doravirine, Lamivudine and Tenofovir disoproxil fumarate in bulk and their combined pharmaceutical formulations. Optimization of Chromatographic separation was achieved on analytical column HSS C18 (100 × 2.1 mm, 1.8 μ) maintained at temperature 30 °C and mobile phase consisting of 0.01 N Potassium dihydrogen orthophosphate buffer (pH-4.8) and acetonitrile in the ratio 60:40 v/v and at a flow rate 0.3 mL/min in isocratic mode. The injection volume was set as 1 µl detection wavelength is 260 nm. The proposed method validation was done as per International Council on Harmonization Q2 (R1) guidelines.

Results

Doravirine, Lamivudine and Tenofovir disoproxil fumarate were eluted at retention times of 1.2, 1.5, and 1.8 min respectively. The proposed method was identified an excellent linearity over concentration range of 12.5–75.0 µg/mL for Doravirine and 37.5–225.0 µg/mL for Lamivudine and 37.5–225.0 µg/mL for Tenofovir disoproxil fumarate. The percentage relative standard deviation for intra-day and inter-day precision of the present method was less than 2% for Doravirine, Lamivudine and Tenofovir disoproxil fumarate. Accuracy of the present method was evaluated by recovery studies which were in the range of 99.62–99.88% for Doravirine and 98.78–99.44% for Lamivudine and 99.67–100.52% for Tenofovir disoproxil fumarate. The limit of detection and limit of quantification were found to be 0.249 µg/mL and 0.756 µg/mL for Doravirine and 0.24 µg/mL and 0.727 µg/mL for Lamivudine and 0.797 µg/mL and 2.966 µg/mL for Tenofovir disoproxil fumarate. Forced degradation studies were carried out under various stress conditions like acid, base, peroxide, thermal, photo and neutral conditions.

Conclusions

The present method makes sure about no degraded impurity peak interference at the retention time of analyte peak hence can be applied for quality control investigation of Doravirine, Lamivudine and Tenofovir disoproxil fumarate in bulk and pharmaceutical formulations.

A simple stability indicating RP-HPLC-DAD method for concurrent analysis of Tenofovir Disoproxil Fumarate, Doravirine and Lamivudine in pure blend and their combined film coated tablets

OBJECTIVES

The main aim of the study was to develop an economical, insightful, accurate and simple RP-HPLC-DAD method with high precision and good sensitivity for concurrent determination of Tenofovir disoproxil fumarate, Doravirine and Lamivudine in blended bulk form and their combined tablet form.

MATERIAL AND METHODS

A method with Ascentis C18 (150×4.6mm, 5μm) column, mobile phase ratio of 0.1% ortho phosphoric acid and Acetonitrile in 70:30 (v/v), 1mL/min flow rate and detection wavelength of 260nm was highly proficient in effective separation of all three drugs. The developed method was validated in accordance with ICH specifications.

RESULTS

The retention times of Doravirine, Lamivudine and Tenofovir disoproxil fumarate observed were 2.4, 2.9, and 3.6min, respectively. The linear responses were observed for Doravirine, Lamivudine and Tenofovir disoproxil fumarate in the range of 12.5-75μg/mL, 75-225μg/mL and 75-225μg/mL, respectively. The limit of detection and quantification values were calculated to be 0.36μg/mL and 0.11μg/mL for Lamivudine, 0.55μg/mL and 1.66μg/mL for Tenofovir disoproxil fumarate and 0.03μg/mL and 0.09μg/mL for Doravirine. The % RSD values of the intra-day and inter-day precision were calculated in the range of 0.134-1.749. The mean percentage recovery of all three analytes was in the range of 98.85-100.18%. The statistical results of the validation parameters ensured that the method was accurate, specific, and precise with good sensitivity. Investigation of analytes under different stressed conditions ensures the stability of analytes reflecting the stability indication of the method. The developed method has high proficiency in separation of Tenofovir disoproxil fumarate, Doravirine and Lamivudine. The degradation products generated due to stress conditions also separated with good resolution.

CONCLUSION

The current method is a stability-indicating assay method consisting of appropriate specificity, accuracy, precision and sensitivity. The developed method has a good potential to be adopted by the pharmaceutical industrial sector.

Analytical Methods for Determination of Antiviral Drugs in Different Matrices: Recent Advances and Trends

Viruses are the main pathogenic substances that cause severe diseases in humans and other living things. They are among the most common microorganisms, and consequently, antiviral drugs have emerged to prevent and treat viral infections. Antiviral drugs are an essential drug group considering their prescription and consumption rates for different diseases and indications. Therefore, it is crucial to develop accurate and precise analytical methods to detect antiviral drugs in various matrices. Chromatographic techniques are used frequently for the quantification purpose since they allow simultaneous determination of antivirals. Electrochemical methods have also gained importance since the analysis can be performed quickly without the need for pretreatment. Spectrophotometric and spectrofluorimetric methods are used because they are simple, inexpensive, and less time-consuming methods. The purpose of this review is to present an overview of the analysis of currently used antiviral drugs from 2010 to 2021. Since studies on antiviral drugs are numerous, selected publications were reviewed in this article. The analysis of antiviral drugs was divided into three main groups: chromatographic, spectrometric, and electrochemical methods which were applied to different matrices, including pharmaceutical, biological, and environmental samples.