Liposomal Formulation Reduces Transport and Cell Uptake of Colistin in Human Lung Epithelial Calu-3 Cell and 3D Human Lung Primary Tissue Models.

Respiratory tract infections caused by multi-drug-resistant (MDR) bacteria have been a severe risk to human health. Colistin is often used to treat the MDR Gram-negative bacterial infections as a last-line therapy. Inhaled colistin can achieve a high concentration in the lung but none of aerosolized colistin products has been approved in the USA. Liposome has been reported as an advantageous formulation strategy for antibiotics due to its controlled release profile and biocompatibility. We have developed colistin liposomal formulations in our previous study. In the present study, the cellular uptake and transport of colistin in colistin liposomes were examined in two human lung epithelium in vitro models, Calu-3 monolayer and EpiAirway 3D tissue models. In both models, cellular uptake (p < 0.05) and cellular transport (p < 0.01) of colistin were significantly reduced by the colistin liposome compared to the colistin solution. Our findings indicate that inhaled colistin liposomes could be a promising treatment for extracellular bacterial lung infections caused by MDR Pseudomonas aeruginosa (P. aeruginosa).

Improved Aerosolization Stability of Inhalable Tobramycin Powder Formulation by Co-Spray Drying with Colistin.

PURPOSE: Tobramycin shows synergistic antibacterial activity with colistin and can reduce the toxic effects of colistin. The purpose of this study is to prepare pulmonary powder formulations containing both colistin and tobramycin and to assess their in vitro aerosol performance and storage stability. METHODS: The dry powder formulations were manufactured using a lab-scale spray dryer. In vitro aerosol performance was measured using a Next Generation Impactor. The storage stability of the dry powder formulations was measured at 22°C and two relative humidity levels - 20 and 55%. Colistin composition on the particle surface was measured using X-ray photoelectron spectroscopy. RESULTS: Two combination formulations, with 1:1 and 1:5 molar ratios of colistin and tobramycin, showed fine particle fractions (FPF) of 85%, which was significantly higher than that of the spray dried tobramycin (45%). FPF of the tobramycin formulation increased significantly when stored for four weeks at both 20% and 55% RH. In contrast, FPF values of both combination formulations and spray dried colistin remained stable at both humidity levels. Particle surface of each combination was significantly enriched in colistin molecules; 1:5 combination showed 77% by wt. colistin. CONCLUSIONS: The superior aerosol performance and aerosolization stability of 1:1 and 1:5 combination formulations of colistin and tobramycin could be attributed to enrichment of colistin on the co-spray dried particle surface. The observed powder properties may be the result of a surfactant-like assembly of these colistin molecules during spray drying, thus forming a hydrophobic particle surface.

Genetic polymorphisms of GSTP1, XRCC1, XPC and ERCC1: prediction of clinical outcome of platinum-based chemotherapy in advanced non-small cell lung cancer patients of Bangladesh.

Inter-individual genetic makeup can trigger variability in platinum-based chemotherapeutic responses and corresponding adverse drug reactions and toxicities. Exploring the genetic causes behind these inter-individual variabilities in platinum-based chemotherapeutic responses by investigating the effects of GSTP1 (rs1695), XRCC1 (rs25487), XPC (rs2228001) and ERCC1 (rs11615) genetic polymorphisms on toxicity and therapeutic response of this treatment among Bangladeshi advanced non-small cell lung cancer (NSCLC) patients was the aim of this study. 285 Clinically proven either stage IIIB or IV (advanced) NSCLC patients aging not less than 18 years old and receiving platinum-based chemotherapy were recruited to assess the influence of these four single nucleotide polymorphisms (SNPs) on peripheral leukocytes. Toxicity and response were evaluated by multivariate regression analyses using SPSS statistical software (version 17.0). XRCC1 (rs25487) polymorphism was found to act as a predictive factor for not only grade 3 and 4 anemia (p = 0.008), neutropenia (p = 0.010), thrombocytopenia (p = 0.025) and gastrointestinal toxicity (p = 0.002) but also for therapeutic response (p = 0.012) in platinum-based chemotherapy. Although GSTP1 (rs1695) polymorphism might serve as prognostic factor regarding grade 3 or 4 neutropenia, a significant (p = 0.044) improvement in response to platinum-based chemotherapy was observed. However, XPC (rs2228001) and ERCC1 (rs11615) polymorphisms could not establish any significant relation with toxicity or therapeutic response. XRCC1 (rs2228001) and GSTP1 (rs1695) polymorphisms might explain platinum-induced clinical outcomes in terms of both toxicity and therapeutic response variations among Bangladeshi advanced NSCLC patients.

Evaluation of serum amino acids and non-enzymatic antioxidants in drug-naïve first-episode major depressive disorder.

BACKGROUND: The alterations of biological markers are thought to be effective tools to understand the pathophysiology and management of major depressive disorder (MDD). A lot of researches has implied many markers for depression, but any of them fully discovered the association between the markers and depression. The present study investigated the serum levels of amino acids and non-enzymatic antioxidants in major depression, and also explained their association with depression. METHODS: This study examined 247 MDD patients and 248 healthy controls (HCs) matched by age and sex. The Hamilton Depression Rating Scale (Ham-D) was used to all the participants to measure the severity of depression. Quantification of serum amino acids, vitamin A and E were carried out using the HPLC system whereas vitamin C levels were measured by UV-spectrophotometer. All the statistical analysis was performed by SPSS statistical software (version 23.0). The independent sample t-test, the Mann-Whitney U test, and the Fisher's exact test were applied to detect the group differences where a Bonferroni correction applied to the p value. RESULTS: It was observed that serum levels of four amino acids (methionine, phenylalanine, tryptophan, and tyrosine) along with three non-enzymatic antioxidants (vitamin A, E, and C) were significantly dropped in MDD patients compared to HCs (Cohen's d (d): - 0.45, - 0.50, - 0.68, - 0.21, - 0.27, - 0.65, and - 0.24, respectively). Furthermore, Ham-D scores of cases were negatively correlated with serum levels of methionine (r = - 0.155, p = 0.015) and tyrosine (r = - 0.172, p = 0.007). CONCLUSION: The present study suggests that lowered serum methionine, phenylalanine, tryptophan, tyrosine, and non-enzymatic antioxidants are associated with depression. The reduction of these parameters in MDD patients may be the consequence, and not the cause, of major depression.

Genetic variants of SULT1A1 and XRCC1 genes and risk of lung cancer in Bangladeshi population.

Lung cancer is one of the most frequently occurring cancers throughout the world as well as in Bangladesh. This study aimed to correlate the prognostic and/or predictive value of functional polymorphisms in SULT1A1 (rs9282861) and XRCC1 (rs25487) genes and lung cancer risk in Bangladeshi population. A case-control study was conducted which comprises 202 lung cancer patients and 242 healthy volunteers taking into account the age, sex, and smoking status. After isolation of genomic DNA, genotyping was done by polymerase chain reaction-restriction fragment length polymorphism method and the lung cancer risk was evaluated as odds ratio that was adjusted for age, sex, and smoking status. A significant association was found between SULT1A1 rs9282861 and XRCC1 rs25487 polymorphisms and lung cancer risk. In case of rs9282861 polymorphism, Arg/His (adjusted odds ratio = 5.06, 95% confidence interval = 3.05-8.41, p < 0.05) and His/His (adjusted odds ratio = 3.88, 95% confidence interval = 2.20-6.82, p < 0.05) genotypes were strongly associated with increased risk of lung cancer in comparison to the Arg/Arg genotype. In case of rs25487 polymorphism, Arg/Gln heterozygote (adjusted odds ratio = 4.57, 95% confidence interval = 2.79-7.46, p < 0.05) and Gln/Gln mutant homozygote (adjusted odds ratio = 4.99, 95% confidence interval = 2.66-9.36, p < 0.05) were also found to be significantly associated with increased risk of lung cancer. This study demonstrates that the presence of His allele and Gln allele in case of SULT1A1 rs9282861 and XRCC1 rs25487, respectively, involve in lung cancer prognosis in Bangladeshi population.

Breast cancer risk in relation to TP53 codon 72 and CDH1 gene polymorphisms in the Bangladeshi women.

Pharmacogenomic studies play a significant role in understanding the risk of breast cancer where genetic abnormalities are implicated as the etiology of cancer. Various polymorphisms of tumor suppressor gene TP53 and E-cadherin (CDH1) have been found to be associated with increased breast cancer risk worldwide. This study aimed to analyze the contribution of TP53 and CDH1 gene anomalies in breast cancer risk in the Bangladeshi breast cancer patients. For risk determination, 310 patients with breast cancer and 250 controls from Bangladeshi women were recruited who are matched up with age and use of contraceptives with patients. Genetic polymorphisms were detected by using polymerase chain reaction restriction fragment length polymorphism. A significant association was found between TP53Arg72Pro (rs1042522) and CDH1 -160 C/A (rs16260) polymorphisms and breast cancer risk. In case of P53rs1042522 polymorphism, Arg/Pro (P = 0.0053, odds ratio (OR) = 1.69) and Pro/Pro (P = 0.018, OR = 1.83) genotypes were associated with increased risk of breast cancer in comparison to the Arg/Arg genotype. Arg/Pro + Pro/Pro genotype and Pro allele also increased the risk of breast cancer (P = 0.002, OR = 1.73; P = 0.004, OR = 1.43, respectively). In case of CDH1rs16260 polymorphism, C/A heterozygote and combined C/A + A/A genotypes were found to be strongly associated (P = 0.005, OR = 1.67; P = 0.0037, OR = 1.68) with increased risk of breast cancer. The variant A allele also increased the breast cancer risk (P = 0.0058, OR = 1.52). The present study demonstrates that P53Arg72Pro and CDH1rs16260 polymorphisms are associated with elevated breast cancer risk in the Bangladeshi population.

Prevalence of CYP2C19 alleles, pharmacokinetic and pharmacodynamic variation of clopidogrel and prasugrel in Bangladeshi population.

The extent to which cytochrome P450 (CYP) 2C19 genotype influences the effectiveness of clopidogrel remains uncertain due to considerable heterogeneity between studies. We used the polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method for genotyping loss of function (LOF) allele, CYP2C19*2 and gain of function (GOF) allele, CYP2C19*17 in 163 patients undergoing PCI and 165 healthy volunteers from an ethnically distinctive Bangladeshi population. Thirty-eight patients took prasugrel and 125 patients took clopidogrel among whom 30 patients had their clopidogrel active metabolites (CAM) determined by LC-MS/MS 1-1.5 h after clopidogrel intake. All patients who underwent PCI had their P2Y12 per cent inhibition (PRI) measured by VerifyNow System. The impact of different genotypes on CAM and PRI were also determined. We did not find significant variation of CYP2C19*2 (P > 0.05) and CYP2C9*17 (P > 0.05) alleles among healthy volunteers and patients. CAM concentration as well as PRI by clopidogrel varied significantly (P < 0.05) based on genotypic variation of CYP2C19*2 and CYP2C19*17 individually. Such influence was not observed in case of prasugrel. Genotypic variation did not impact PRI but as a whole PRI by prasugrel was better than that of clopidogrel (P < 0.05). Due to presence of both of alleles the effect on PRI by clopidogrel could not be predicted, effectively indicating possible involvement of other factors. Genotype guided clopidogrel dose adjustment would be beneficial and therefore we propose mandatory genotyping before clopidogrel dosing. Prasugrel proved to be less affected by genotypic variability, but due to lack of sufficient long-term toxicity data, caution would be adopted before substituting clopidogrel.

Lung cancer risk in relation to TP53 codon 47 and codon 72 polymorphism in Bangladeshi population.

The objective of this study was to determine whether p53 codon 47 and codon 72 polymorphisms are associated with increased risk of lung cancer in Bangladeshi population. We carried out a case-control study and examined the genotype distribution Pro47Ser and Arg72Pro single-nucleotide polymorphisms along with tobacco smoking in the predisposition of lung cancer by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) approach. The study included 106 lung cancer patients and 116 control subjects from Bangladesh. Lung cancer risk was estimated as odds ratio (OR) and 95 % confidence interval (CI) using conditional logistic regression models adjusting for age, sex, and smoking. No significant association was found between Pro47Ser SNP and lung cancer. The frequencies of p53 codon 72 polymorphisms (Arg/Arg, Arg/Pro, and Pro/Pro) in lung cancer were 25.5, 37.7, and 36.8 %, respectively; frequencies in the controls were 53.4, 30.2, and 16.4 %, respectively (p < 0.01). The Arg/Pro and Pro/Pro genotype were significantly associated with increased risk of lung cancer (OR = 2.51, 95 % CI = 1.38-4.82 and OR = 4.62, 95 % CI = 2.31-9.52, respectively) compared with the Arg/Arg genotype. The combined frequency of Arg/pro and Pro/Pro genotype was also found to be associated with elevated risk of lung cancer (OR = 3.36, 95 % CI = 1.90-5.94, p < 0.01). However, no significant relationship was found between age, sex, and histological subtypes of lung cancer with p53 codon 72 genotype distributions. When classified by smoking status, the effects of Arg72Pro polymorphism on lung cancer risk was only found to be significant (χ (2) = 33.94, p = 0.00000004) in case of heavy smokers (40 packs per year or more). We conclude that not Pro47Ser SNP but Arg72Pro SNP is involved in susceptibility to developing lung cancer, at least in Bangladeshi population.

Association of CYP3A4, CYP3A5 polymorphisms with lung cancer risk in Bangladeshi population.

The rate of direct smoking, second hand smoking, and smokeless tobacco users as well as the amount of environmental pollutant like polycyclic aromatic hydrocarons is increasing in Bangladesh. Therefore, the prevalence of lung cancer is increasing day by day. To the best of our knowledge, no pharmacogentic study of CYP3A4, CYP3A5 genes has been reported on Bangladeshi population relating those with lung cancer. The present study was conducted to determine the association of CYP3A4, CYP3A5 gene polymorphisms and tobacco smoking in the development of lung cancer in Bangladeshi population. A case-control study was carried out on 106 lung cancer patients and 116 controls to investigate three allelic variants-CYP3A4*1B, CYP3A5*3, and CYP3A5*6 using Polymerase Chain Reaction Restriction Fragment Length Polymorphism. Risk of lung cancer was estimated as odds ratio (OR) and 95 % confidence interval (CI) using unconditional logistic regression models. The variant allele frequencies for CYP3A4*1B (*1A/*1B + *1B/*1B) were 2.83 % and 0.86 % and that of CYP3A5*3 (*1A/*3 + *3/*3) were 88.68 % and 85.34 % in cases and controls, respectively. Individual carrying at least one variant allele of CYP3A4*1B (CYP3A4*1A/1B + *1B/1B) has a 3.35 times more risk (OR = 3.35, 95 % Cl = 0.34-32.71, p = 0.271) for developing lung cancer whereas individual carrying at least one variant allele of CYP3A5 (CYP3A5*1A/3 + *3/3) has a 1.26 times more risk (OR = 1.35, 95 % Cl = 0.61-2.97) and both are statistically non-significant (p > 0.05). CYP3A5*6 was absent in the study population. No association of lung cancer with the mentioned polymorphisms was found both in heavy and light smokers. In the cases of all three major types of lung cancer-squamous cell carcinoma, adenocarcinoma, and small cell carcinoma-significantly strong relationships (p ˂ 0.05) have been found. To confirm the association of lung cancer with the mentioned polymorphisms, large number volunteers (patients and controls) will be required.

N-acetyltransferase 2 (NAT2) genotype as a risk factor for development of drug-induced liver injury relating to antituberculosis drug treatment in a mixed-ethnicity patient group.

PURPOSE: This study aims to assess whether NAT2 genotype affects susceptibility to moderate to severe liver injury in patients undergoing drug treatment for tuberculosis with isoniazid-containing regimens. METHODS: Twenty-six patients of European or South Asian ethnicity, who had suffered liver injury during treatment with isoniazid-containing drug regimens and 101 ethnically matched controls were genotyped for the NAT2*5, NAT2*6, and NAT2*7 alleles. Genotyping for additional polymorphisms in the NAT gene region was also performed on 20 of the 26 cases. NAT2 genotype frequency between cases and controls was compared. RESULTS: NAT2 genotypes predicting a slow acetylator phenotype were found to be associated with an increased risk of isoniazid-related liver injury (odds ratio (OR) = 4.25 (95% confidence interval (CI), 1.36-13.22); p = 0.012) with 85% of the cases being slow acetylators compared with 56% of the controls. There was no evidence for an increased risk for the slow acetylator genotype in patients with the most severe cases of liver injury, who underwent liver transplantation. CONCLUSIONS: The NAT2 slow acetylator genotype appears to be a significant risk factor for moderate and severe drug- induced liver injury. However, the overall effect size is modest and generally in line with effects described previously for this genotype in milder drug-induced liver injury. Additional genetic risk factors may also contribute.

Tobramycin Reduces Pulmonary Toxicity of Polymyxin B via Inhibiting the Megalin-Mediated Drug Uptake in the Human Lung Epithelial Cells.

Accumulation of polymyxins in the lung epithelial cells can lead to increased mitochondrial oxidative stress and pulmonary toxicity. Aminoglycosides and polymyxins are used, via intravenous and pulmonary delivery, against multidrug-resistant Gram-negative pathogens. Our recent in vitro and animal studies demonstrated that the co-administration of polymyxins with aminoglycosides decreases polymyxin-induced pulmonary toxicity. The aim of this study was to investigate the in vitro transport and uptake of polymyxin B and tobramycin in human lung epithelial Calu-3 cells and the mechanism of reduced pulmonary toxicity resulting from this combination. Transport, intracellular localization, and accumulation of polymyxin B and tobramycin were investigated using doses of 30 mg/L polymyxin B, 70 mg/L tobramycin, and the combination of both. Adding tobramycin significantly (p < 0.05) decreased the polymyxin B-induced cytotoxicity in Calu-3 cells. The combination treatment significantly reduced the transport and uptake of polymyxin B and tobramycin in Calu-3 cells, compared to each drug alone, which supported the reduced pulmonary toxicity. We hypothesized that cellular uptake of polymyxin B and tobramycin shared a common transporter, megalin. We further investigated the megalin expression of Calu-3 cells using confocal microscopy and evaluated megalin activity using a megalin substrate, FITC-BSA, and a megalin inhibitor, sodium maleate. Both polymyxin B and tobramycin significantly inhibited FITC-BSA uptake by Calu-3 cells in a concentration-dependent manner. Sodium maleate substantially inhibited polymyxin B and tobramycin transport and cellular accumulation in the Calu-3 cell monolayer. Our study demonstrated that the significantly reduced uptake of polymyxin B and tobramycin in Calu-3 cells is attributed to the mechanism of action that determines that polymyxin B and tobramycin share a common transporter, megalin.

Genotype-phenotype variability in human CYP3A locus in Nepalese people residing in Bangladesh.

OBJECTIVES: The study has been designed to phenotype 200 Nepalese people residing in Bangladesh by measuring urinary ratio of 6ß-hydroxycortisol/cortisol (metabolic ratio) and to genotype all the subjects for the presence of CYP3A4*1B, *2, *4, *5, *6, *10, *18, CYP3A5*3, and *6 alleles. METHODS: Cortisol and 6ß-hydroxycortisol were extracted and quantified from morning spot urine samples (n = 200) by HPLC. Genotyping was carried out using the extracted genomic DNA by amplification of target alleles by PCR. Amplified DNA was digested by appropriate restriction enzymes followed by gel electrophoresis and sequencing to identify the targeted alleles. RESULTS: A wide ratio of 6ß-hydroxycortisol/cortisol was found (0.71 - 10.61) with an average of 4.41. No sample (n = 200) was found positive for CYP3A4*1B, *2, *4, *5, *6, *10, *18, and CYP3A5*6 alleles. CYP3A5*1/*1, *1/*3, and *3/*3 genotype frequency were found to be 20%, 20%, and 60%, respectively. A significantly higher mean metabolic ratio (MR) ± SD (MR = 6.28 ± 3.43) was found for CYP3A5*1/*1 compared to both CYP3A5*1/*3 (MR = 3.68 ± 1.37) and CYP3A5*3/*3 (MR = 3.58 ± 1.95). CONCLUSION: This study demonstrates the absence of common CYP3A4 variant alleles in Nepalese people residing in Bangladesh whereas Nepalese people carrying the CYP3A5*1/*1 genotype appear to show a significantly higher 6ß-hydroxycortisol/cortisol ratios compared to those with CYP3A5*3/*3 genotype.

Evaluation of inflammatory cytokines in drug-naïve major depressive disorder: A systematic review and meta-analysis.

Objective: Altered levels of peripheral inflammatory and proinflammatory cytokine markers affect the different clinical stages of major depressive disorder (MDD). A concrete understanding of the causal mechanism of MDD is a prerequisite in developing treatment strategies and preventive plans. Here we aimed to conduct an updated systematic review and meta-analysis of studies assessing the association of C-reactive protein (CRP), INF-γ, MCP-1, and TNF-α in the peripheral fluid of drug-naïve MDD patients and healthy controls (HCs). Methods: We extracted articles from PubMed, ProQuest, PsycINFO, Web of Science, and Scopus databases from inception until 14 February 2021, to find relevant studies. In this meta-analysis, we included a total of 23 eligible studies (1,366 MDD patients and 1,342 controls) in the final meta-analysis. The Cochran's chi-square Q-test and I2-index were applied to measure the heterogeneity and inconsistency of all combined results. We selected a random-effect model during the analysis and measured publication biases using the funnel plot. We performed Bonferroni adjustment for multiple testing. Results: We found a high level of TNF-α in MDD patients than in control subjects Standardized Mean Difference (SMD) with a random-effects model: 1.04, 95% CI: 0.69-1.39, z = 5.84, p < 0.001). The levels of CRP (SMD with a random-effects model: 0.18, 95% CI: -0.85-1.23, z = 0.35, p = 0.73), INF-ɤ (SMD with a random-effects model: -0.05, 95% CI: -2.72-2.62, z = 0.03, p = 0.97), and MCP-1 (SMD with a random-effects model: 0.70, 95% CI: -0.09-1.49, z = 1.73, p = 0.08) were not significantly varies between MDD patients and HCs. Conclusion: The present study findings suggest the upregulated level of peripheral TNF-α but not CRP, INF-γ, and MCP-1 involve in depression. The elevated inflammatory cytokines confirmed the inflammatory state of depression. Therefore, inflammatory cytokines might serve as potential risk assessment markers in MDD.

Polymyxin B sulfate inhalable microparticles with high-lectin-affinity sugar carriers for efficient treatment of biofilm-associated pulmonary infections.

Pulmonary infections caused by multidrug-resistant bacteria have become a significant threat to human health. Bacterial biofilms exacerbate the persistence and recurrence of pulmonary infections, hindering the accessibility and effectiveness of antibiotics. In this study, a dry powder inhalation (DPI) consisting of polymyxin B sulfate (PMBS) inhalable microparticles and high-lectin-affinity (HLA) sugar (i.e., raffinose) carriers was developed for treating pulmonary infections and targeting bacterial lectins essential for biofilm growth. The formulated PMBS-HLA DPIs exhibited particle sizes of approximately 3 µm, and surface roughness varied according to the drug-to-carrier ratio. Formulation F5 (PMBS: raffinose = 10:90) demonstrated the highest fine particle fraction (FPF) value (64.86%), signifying its substantially enhanced aerosol performance, potentially attributable to moderate roughness and smallest mass median aerodynamic particle size. The efficacy of PMBS-HLA DPIs in inhibiting biofilm formation and eradicating mature biofilms was significantly improved with the addition of raffinose, suggesting the effectiveness of lectin-binding strategy for combating bacterial biofilm-associated infections. In rat models with acute and chronic pulmonary infections, F5 demonstrated superior bacterial killing and amelioration of inflammatory responses compared to spray-dried PMBS (F0). In conclusion, our HLA carrier-based formulation presents considerable potential for the efficient treatment of multidrug-resistant bacterial biofilm-associated pulmonary infections.

Comparative pharmacokinetic and bioequivalence study of azithromycin 500 mg tablet in healthy Bangladeshi volunteers.

OBJECTIVE: Although several generic oral formulations of azithromycin (AZT; CAS 83905-01-5) are available in Bangladesh, information regarding the bioavailability of these formulations in the Bangladeshi population is unavailable. The purpose of this study was to compare the relative bioavailability and other pharmacokinetic properties of 2 formulations of AZT 500 mg tablet, namely Azomac® (General Pharmaceutical Ltd., Bangladesh) (Test formulation) and Zithromax® (Pfizer, Rome, Italy) (Reference product) and to evaluate whether these formulations meet the FDA criteria to assume bioequivalence in Bangladeshi volunteers. MATERIALS AND METHODS: A randomized, single-dose, two-way, cross-over, open-label pharmacokinetic study was performed in 24 healthy volunteers after administration of single dose of AZT 500 mg tablet under fasting condition following a washout period of 3 weeks. Blood samples were collected at pre-determined time points and analyzed for serum AZT concentration using a validated liquid chromatography-tandem mass spectrometry method. The pharmacokinetic parameters were determined by a noncompartmental method. RESULTS: From serum data, the obtained values given as mean (SD) for test and reference products were 382.41 (21.96), 392.31 (18.77) ng/ml for Cmax; 4.83(1.03), 4.83(1.03) h for tmax; 5,646.29 (912.19), 6,293.30 (966.76) h×ng/ml for AUC0-120; and 6,307.50 (863.40), 7,022.54 (961.28) h×ng/ml for AUC0-∞, respectively. The mean t1/2 was 41.44 (7.01), 41.16 (6.38) h for Test formulation and Reference product, respectively. The analysis of variance revealed no period or sequence effect for any pharmacokinetic property; however, a significant formulation effect was observed for Cmax, AUC0-120, AUC0-∞ and AUMC0-120. The 90% confidence intervals of the test/ reference mean ratios of the ln-transformed Cmax, AUC0-120 and AUC0-∞ were 87.89 - 89.36%, 87.40 - 91.70% and 87.47 - 92.07%, respectively, which fell within the predetermined FDA bioequivalence range. CONCLUSION: It can be concluded that the test formulation met the regulatory criteria for bioequivalence to the Reference tablet formulation in terms of both rate and extent of absorption.

Spray-freeze-dried inhalable composite microparticles containing nanoparticles of combinational drugs for potential treatment of lung infections caused by Pseudomonas aeruginosa.

The multi-drug resistance of Pseudomonas aeruginosa is an overwhelming cause of terminal and persistent lung infections in cystic fibrosis (CF) patients. Antimicrobial synergy has been shown for colistin and ivacaftor, and our study designed a relatively high drug-loading dry powder inhaler formulation containing nanoparticles of ivacaftor and colistin. The ivacaftor-colistin nanosuspensions (Iva-Col-NPs) were prepared by the anti-solvent method with different stabilizers. Based on the aggregation data, the formulation 7 (F7) with DSPG-PEG-OMe as the stabilizer was selected for further studies. The F7 consisted of ivacaftor, colistin and DSPG-PEG-OMe with a mass ratio of 1:1:1. The F7 powder formulation was developed using the ultrasonic spray-freeze-drying method and exhibited a rough surface with relatively high fine particle fraction values of 61.4 ± 3.4% for ivacaftor and 63.3 ± 3.3% for colistin, as well as superior emitted dose of 97.8 ± 0.3% for ivacaftor and 97.6 ± 0.5% for colistin. The F7 showed very significant dissolution improvement for poorly water soluble ivacaftor than the physical mixture. Incorporating two drugs in a single microparticle with synchronized dissolution and superior aerosol performance will maximize the synergy and bioactivity of those two drugs. Minimal cytotoxicity in Calu-3 human lung epithelial cells and enhanced antimicrobial activity against colistin-resistant P. aeruginosa suggested that our formulation has potential to improve the treatment of CF patients with lung infections.

Pan-transcriptomic analysis identified common differentially expressed genes of Acinetobacter baumannii in response to polymyxin treatments.

Multidrug-resistant Acinetobacter baumannii is a top-priority Gram-negative pathogen and polymyxins are a last-line therapeutic option. Previous systems pharmacological studies examining polymyxin killing and resistance usually focused on individual strains, and the derived knowledge could be limited by strain-specific genomic context. In this study, we examined the gene expression of five A. baumannii strains (34654, 1207552, 1428368, 1457504 and ATCC 19606) to determine the common differentially expressed genes in response to polymyxin treatments. A pan-genome containing 6061 genes was identified for 89 A. baumannii genomes from RefSeq database which included the five strains examined in this study; 2822 of the 6061 genes constituted the core genome. After 2 mg L-1 or 0.75 × MIC polymyxin treatments for 15 min, 41 genes were commonly up-regulated, including those involved in membrane biogenesis and homeostasis, lipoprotein and phospholipid trafficking, efflux pump and poly-N-acetylglucosamine biosynthesis; six genes were commonly down-regulated, three of which were related to fatty acid biosynthesis. Additionally, comparison of the gene expression at 15 and 60 min in ATCC 19606 revealed that polymyxin treatment resulted in a rapid change in amino acid metabolism at 15 min and perturbations on envelope biogenesis at both time points. This is the first pan-transcriptomic study for polymyxin-treated A. baumannii and our results identified that the remodelled outer membrane, up-regulated efflux pumps and down-regulated fatty acid biosynthesis might be essential for early responses to polymyxins in A. baumannii. Our findings provide important mechanistic insights into bacterial responses to polymyxin killing and may facilitate the optimisation of polymyxin therapy against this problematic 'superbug'.

Pharmacogenetic Variants in MTHFR Gene are Significant Predictors of Methotrexate Toxicities in Bangladeshi Patients With Acute Lymphoblastic Leukemia.

BACKGROUND: The objective of this pharmacogenetic study was to investigate the relationship of methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms with methotrexate (MTX)-induced toxicities and plasma homocysteine level in patients with acute lymphoblastic leukemia (ALL) from Bangladesh. Several polymorphisms result in reduced MTHFR activity that causes impaired remethylation of homocysteine to methionine and abnormal MTX metabolism, especially in tissues with high turnover. Therefore, the risk of elevated plasma homocysteine as well as MTX-induced toxicities become higher with MTHFR polymorphisms. PATIENTS AND METHODS: We recruited 160 patients with ALL receiving MTX containing chemotherapeutic protocol, and they were genotyped for MTHFR C677T and A1298C polymorphisms with polymerase chain reaction-restriction fragment length polymorphism. We also measured the plasma homocysteine level of 51 patients by the AxSYM homocysteine assay method. RESULTS: We found 68.1% CC, 26.3% CT, and 5.6% TT genotype for MTHFR C677T polymorphism and 39.3% AA, 46.9% AC, and 13.8% CC genotype for MTHFR A1298C polymorphism in patients with ALL. Our study suggested that MTX-induced mucositis and diarrhea are significantly associated with MTHFR C677T as well as MTHFR A1298C polymorphisms (P < .05). CONCLUSION: The risk of elevated plasma homocysteine level was 5 to 6 times higher for both polymorphisms. This study may help to identify the patients who are at higher risk for MTX-related toxicities.

DPYD*2A and MTHFR C677T predict toxicity and efficacy, respectively, in patients on chemotherapy with 5-fluorouracil for colorectal cancer.

BACKGROUND: Significant inter-individual variation in the sensitivity to 5-fluorouracil (5-FU) represents a major therapeutic hindrance either by impairing drug response or inducing adverse drug reactions (ADRs). This study aimed at exploring the cause behind this inter-individual alterations in consequences of 5-fluorouracil-based chemotherapy by investigating the effects of DPYD*2A and MTHFR C677T polymorphisms on toxicity and response of 5-FU in Bangladeshi colorectal cancer patients. METHODS: Colorectal cancer patients (n = 161) receiving 5-FU-based chemotherapy were prospectively enrolled. DPYD and MTHFR polymorphisms were assessed in peripheral leukocytes. Multivariate analyses were applied to evaluate which variables could predict chemotherapy-induced toxicity and efficacy. RESULTS: Multivariate analyses showed that DPYD*2A polymorphism was a predictive factor (P = 0.023) for grade 3 and grade 4 5-fluorouracil-related toxicities. Although MTHFR C677T polymorphism might act as forecasters for grade 3 or grade 4 neutropenia, diarrhea, and mucositis, this polymorphism was found to increase significantly (P = 0.006) the response of 5-FU. CONCLUSION: DPYD*2A and MTHFR C677T polymorphisms could explain 5-FU toxicity or clinical outcome in Bangladeshi colorectal patients.

Association of BRCA1, BRCA2, RAD51, and HER2 gene polymorphisms with the breast cancer risk in the Bangladeshi population.

PURPOSE: Breast cancer is considered as the most frequent female malignancy. Altered gene expressions due to genetic polymorphisms in the BRCA1, BRCA2, RAD51, and HER2 contribute toward the development of breast cancer, and yet, no such type of study has been conducted in the Bangladeshi population. This study was designed to evaluate the role of BRCA1rs80357713, BRCA1rs80357906, BRCA2rs11571653, RAD51rs1801320, and HER2rs1136201 polymorphisms as risk factors in the development of breast cancer in the Bangladeshi population. METHODS: A total 310 patients with invasive breast cancers were recruited as cases from different public and private hospitals of Bangladesh, and 250 Bangladeshi healthy women matching age with the patients were recruited as controls. Polymerase chain reaction-restriction fragment length polymorphism method was used to analyze the genetic polymorphisms. RESULTS: Patients carrying BRCA1/2 mutations, GC and GC plus CC genotypes of RAD51rs1801320, and AG plus GG genotype of HER2rs1136201 polymorphisms were found to be associated with breast cancer. In subgroup analysis, AG plus GG genotype of HER2rs1136201 was found to be associated with the breast cancer risk in the patients younger than 45 years of age compared with the older patients having more than 45 years of age, and RAD51rs1801320 was related to the tumor size and tumor aggressiveness (higher graded tumor). CONCLUSION: Our results indicate that BRCA1/BRCA2, RAD51rs1801320 and HER2rs1136201 polymorphisms were associated with breast cancer in the studied population.