Transcriptomic interplay between Acinetobacter baumannii , human macrophage and polymyxin.

Optimization of antibiotic therapy has been hindered by our dearth of understanding on the mechanism of the host-pathogen-drug interactions. Here, we employed dual RNA-sequencing to examine transcriptomic perturbations in response to polymyxin B in a co-culture infection model of Acinetobacter baumannii and human macrophages. Our findings revealed that polymyxin B treatment induced significant transcriptomic response in macrophage-interacting A. baumannii , exacerbating bacterial oxidative stress, disrupting metal homeostasis, affecting osmoadaptation, triggering stringent stress response, and influencing pathogenic factors. Moreover, infected macrophages adapt heme catabolism, coagulation cascade, and hypoxia-inducible signaling to confront bacterial invasion. Disrupting rcnB , ompW , and traR/dksA genes in A. baumannii impairs metal homeostasis, osmotic stress defense and stringent responses, thereby enhancing antibacterial killing by polymyxin. These findings shed light on the global stress adaptations at the network level during host-pathogen-drug interactions, revealing promising therapeutic targets for further investigation. IMPORTANCE: In the context of the development of bacterial resistance during the course of antibiotic therapy, the role of macrophages in shaping bacterial response to antibiotic killing remains enigmatic. Herein we employed dual RNA-sequencing and an in vitro tripartite model to delve into the unexplored transcriptional networks of the Acinetobacter baumannii -macrophage-polymyxin axis. Our findings uncovered the potential synergy between macrophages and polymyxin B which appear to act in co-operation to disrupt multiple stress tolerance mechanisms in A. baumannii . Notably, we discovered the critical roles of bacterial nickel/cobalt homeostasis ( rcnB family), osmotic stress defense ( ompW family), and stringent response regulator ( traR/dksA C4-type zinc finger) in tolerating the last-line antibiotic polymyxin B. Our findings may lead to potential targets for the development of novel therapeutics against the problematic pathogen A. baumannii .

Prevalence and risk factors for uveitis in spondyloarthritis.

AIM: To determine the prevalence and risk factors for uveitis in spondyloarthritis (SpA) patients. METHODS: A total of 225 patients who fulfilled Assessment of Spondyloarthritis International Society classification criteria for axial and peripheral SpA were enrolled. The diagnosis of uveitis was confirmed by an ophthalmologist. From medical records and from clinical evaluation associated information like disease duration, and human leukocyte antigen B27 was collected. Relevant laboratory tests were done and disease severity was assessed using Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Ankylosing Spondylitis Disease Activity Score - erythrocyte sedimentation rate and C-reactive protein. Characteristics of uveitis positive and uveitis negative groups were compared. Multivariate logistic regression analysis was done for the risk factors, and P values <.05 were considered significant. RESULTS: Prevalence of uveitis was 18.7%. The disease duration was 9.3 ± 7 years and 5.4 ± 4.5 years in uveitis and no uveitis groups respectively (P ≤ .001). Family history of SpA was positive in 45.2% in the uveitis group (P ≤ .001). The frequency of axial SpA was 92.9% and 73.8% in the uveitis and no uveitis groups respectively (P ≤ .008). The mean BASDAI was 2.4 ± 1.9 and 3.3 ± 2.8 in uveitis and no uveitis groups respectively (P = .050). In multivariate logistic regression analysis, among the selected variables, family history of SpA (odds ratio [OR] =3.697; 95% CI =1.616-8.457; P = .002) and duration of disease (OR =1.089; 95% CI =1.004-1.181; P = .039) were independently associated with the occurrence of uveitis. CONCLUSIONS: The prevalence of uveitis was 18.7%. The family history and the disease duration of SpA were independently associated with uveitis.

Development of a Bangla version of the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and the Bath Ankylosing Spondylitis Functional Index (BASFI).

AIM: Development of a Bangla version of the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and the Bath Ankylosing Spondylitis Functional Index (BASFI). METHODS: This biphasic observational study performed the translation and adaptation of the questionnaires carried out in 5 steps with pre-testing in 30 AS patients followed by the psychometric validation of the pre-final Bangla version utilizing content and construct validity in 115 AS patients. The reliability was examined through internal consistency and test-retest reliability involving 23 AS patients. RESULTS: After pre-testing of the pre-final Bangla version of both indices, the psychometric validation found that the convergent validity of Bangla version of BASDAI showed strong correlation with C-reactive protein (r = .75) and the Maastricht Ankylosing Spondylitis Enthesitis (r = .64), and moderate correlation with erythrocyte sedimentation rate (r = .49). Again, the Bangla BASFI showed significant correlation with occiput-to-wall distance (OWD) (r = .50), mentum-to-sternum distance (MSD) (r = .50), chest expansion (CE) (r = -.40), finger-to-floor (FFD) (r = .55), number of swollen joints (r = .69), and number of enthesitis (r = .68). The divergent validity demonstrated weak correlations between BASDAI and OWD (r = .43), MSD (r = .34), CE (r = -.44), FFD (r = .47). The divergent validity of BASFI could not be assessed due to lack of a suitable comparing parameter. The instruments revealed acceptable internal consistency as Cronbach's alpha was 0.86 for BASDAI and 0.93 for BASFI. A 7-day test-retest reliability measured by the intraclass correlation coefficient were 0.80 (CI at 95% = 0.58-0.90) for BASDAI and 0.83 (CI at 95% = 95% 0.64-0.92) for BASFI respectively. CONCLUSIONS: Bangla version of BASDAI and BASFI may be useful in disease activity and functional ability assessment in AS patients.

Translation, cross-cultural adaptation and validation of the English Lequesne Algofunctional index in to Bengali.

BACKGROUND: This study was focused on translation and cultural adaptation of the English Lequesne Algofunctional index (LAI) into Bengali for patients with primary knee osteoarthritis (OA) and testing reliability and validity of the Bengali version of the LAI. METHODS: This study was carried out in the Department of Rheumatology, BSM Medical University, Dhaka, Bangladesh. Using the forward-backward method the English LAI was translated into Bengali including cultural adaptation. For pretesting, A sample of 40 patients with primary knee osteoarthritis were screened using the Bengali version of LAI. Following the pretest, 130 consecutive patients with symptomatic knee OA completed the interviewer administered Bengali LAI, the validated Bengali version of SF-36, Visual Analogue Scale for Pain, Distance Walked and Activities of Daily Living. For the retest 60 randomly selected patients from the cohort were administered the Bengali LAI 7 days later. An item by item analysis was performed. Internal consistency was assessed by Cronbach's alpha, test-retest reliability by intraclass correlation coefficient (ICC) and Kappa coefficient, construct validity was measured using the Spearman rank correlation coefficient. RESULTS: It took 3.25 ± 0.71 min to complete the Bengali LAI and the mean score was 9.23 ± 4.58. For the Bengali LAI Cronbach's alpha score was 0.88, test-retest reliability assessed by ICC was 0.97. For construct validity, excellent convergent validity was achieved (ρ = 0.93) but the divergent validity was moderate (ρ = 0.43). CONCLUSIONS: The Bengali LAI showed excellent convergent validity, internal consistency and test-retest reliability, only the divergent validity was moderate. So, the Bengali LAI can be applied as a HRQoL assessment tool for primary knee OA patients.

Eosinophilic fasciitis: what matters in management in a developing country--a case report with two and a half-year follow-up.

Eosinophilic fasciitis is an uncommon disorder of unknown aetiology and poorly-understood pathogenesis. Since 1974, over 250 cases of eosinophilic fasciitis have been reported worldwide. The first case of eosinophilic fasciitis from Bangladesh is reported here. The challenges of diagnosis, treatment, and follow-up, including family and social support, are discussed.

Investigation of serum trace element, malondialdehyde and immune status in drug abuser patients undergoing detoxification.

Drug abuser patients (n=104), age ranging from 19 to 42 years, were randomly recruited to investigate the serum levels of trace elements (Cu, Zn, Fe, and Mg), malondialdehyde (MDA), and immunoglobulin (IgG, IgA, and IgM) before and after clinical intervention. Control group also included 104 healthy individuals. Blood samples were analyzed for determining trace elements, MDA, and immunoglobulin using atomic absorption spectroscopy, Ultraviolet-Visible (UV-VIS) spectroscopy, and turbidimetry method, respectively. For serum level of Zn and Fe, the differences between the groups (before intervention, after intervention, and control) were not significant (p>0.05). However, significant differences were found in serum copper levels between control group, drug abuser patients, and before and after intervention (p<0.05). The concentration of Mg was found to be significantly higher (p=0.007) in drug abuser patients than the controls, and after intervention, the level was restored to control value. A displacement of elemental homeostasis was observed in drug abuser patients compared to control, and it was improved after intervention. An increase in serum concentration of MDA was found in drug abuser patients compared to control subjects (p>0.05) but was not statistically significant. After intervention, the concentration was restored to control value (p>0.05). The serum concentrations of IgA and IgM were found to be significantly higher (p<0.05) in drug abuser patients before intervention than the controls, and the level tended to be restored to control level after clinical intervention. Serum IgG level was found to be lower in drug abuser patients compared to controls and further declined significantly (p<0.05) after intervention. These findings may suggest a possible imbalance in the levels of micronutrients, antioxidants, and immunoglobulin in drug abuser patients, which tend to be restored to control values after detoxification.

Relative bioavailability and pharmacokinetic properties of two different enteric formulations of esomeprazole in healthy Bangladeshi male volunteers: An open-label, single-dose, randomized-sequence, two-way crossover study.

BACKGROUND: In Bangladesh, a number of generic oral formulations of esomeprazole are marketed. Study of the relative bioavailability of these generic formulations has yet to be conducted in a Bangladeshi population. OBJECTIVES: The aims of this study were to assess the relative bioavailability and pharmacokinetic properties of 2 formulations (test and reference) of esomeprazole 40 mg. METHODS: This open-label, randomized, 2-way crossover study was conducted in healthy Bangladeshi male subjects in compliance with the Declaration of Helsinki and International Conference on Harmonisation guidelines. Subjects were randomly assigned to receive the test formulation followed by the reference formulation or vice versa, as a single dose of esomeprazole 40 mg after a 12-hour overnight fast. A washout period of 1 week was maintained between treatments. Following oral administration, blood samples were collected at 0, 0.5, 0.75, 1, 1.25, 1.5, 1.75, 2, 2.25, 2.5, 2.75, 3, 3.5, 4, 5, 7, 9, and 12 hour(s) after dosing and analyzed for esomeprazole concentrations using a validated HPLC method. Pharmacokinetic parameters, including C(max), AUC(0-12), and AUC(0-infinity), were determined with a non-compartmental method. The formulations were to be considered bioequivalent if the natural log (ln)-transformed ratios of the pharmacokinetic parameters were within the predetermined bioequivalence range of 80% to 125%, according to the US Food and Drug Administration (FDA) requirement. The within- and between-group differences were examined using ANOVA. Tolerability was assessed by monitoring vital signs and conducting subject interviews regarding adverse events. Interviewers were not blinded to study design. RESULTS: A total of 24 nonsmoking, healthy, Bangladeshi male subjects (mean [SD] age, 22.8 [2.22] years [range, 20-29 years]; weight, 64.7 [6.9] kg [range, 55-79 kg]; height, 1.69 [0.05] m [range, 1.63-1.82 m]; and body mass index, 22.39 [2.16] kg/m(2) [range, 18.99-27.34 kg/m(2)]) were enrolled. From serum data, the mean (SD) values for the test and reference products were as follows: 5.26 (1.57) and 5.54 (2.94) micromol/L for C(max); 2.53 (0.67) and 2.07 (0.65) hours for T(max); 15.74 (6.50) and 16.68 (6.77) micromol/L/h for AUC(0-12); and 17.15 (7.58) and 18.26 (7.31) micromol/L/h for AUC(0-infinity), respectively. The mean T(max) was found to be significantly different between the test and reference formulations (2.53 [0.67] vs 2.07 [0.65] hours, respectively; P < 0.05). The point estimates (90% CI) for the test/reference ratios of the In-transformed AUC(0-infinity) and C(max) were 92.92% (84.02%-102.76%) and 102.36% (85.96%-121.90%), respectively, which were within the FDA-accepted limits for assuming bioequivalence. No adverse events were reported by the volunteers during the study. CONCLUSION: This single-dose study found that the test and reference formulations of esomeprazole 40 mg met the FDA regulatory criteria for assuming bioequivalence in these healthy, fasting Bangladeshi male volunteers. A significant difference was found in T(max) between the 2 formulations. Both formulations were well tolerated in the studied population.

Interaction study between levofloxacin and omeprazole using urinary pharmacokinetic data.

The objective of this study was to observe the drug interaction between levofloxacin and omeprazole using urinary excretion data. Levofloxacin tablet and omeprazole capsule were administered separately as well as in combination in fasting condition with a wash out period of two weeks after each administration. Urine was collected at different time intervals of 0, 0-2, 2-4, 4-8, 8-12, 12-24, 24-36 and 36-48 hr post-dose and analyzed using a validated HPLC with UV detection. Different pharmacokinetic parameters for both drugs were determined using non-compartmental method. The maximum rate of excretion (R(max)) of levofloxacin was not decreased significantly when co-administered with omeprazole (p<0.05). Similarly no significant difference (p = 0.350) was observed for Rmax of omeprazole when co-administered with levofloxacin. Again the fraction of levofloxacin excreted (f(e)/f) was not changed significantly (p = 0.953) due to the co-administration of omeprazole. Similarly fraction of omeprazole excreted (f(e)/f) also remained unaffected (p = 0.672) when co-administered with levofloxacin. No significant change was observed for the area under the rate of excretion versus midpoint of time interval curve from zero to 48 hours (AURC(0-48)) for levofloxacin and omeprazole (p = 0.816 and 0.792 respectively) when administered separately and co-administered with each other. The study clearly revealed that levofloxacin and omeprazole do not undergo any kind of interactions when administered together. So it can be concluded that these two drugs can be prescribed together to achieve optimum therapeutic activity.

Immunoglobulin levels of vitiligo patients.

In the present study, the serum immunoglobulin profiles of vitiligo patients were compared with that of cohort control and evaluated the correlation between immunoglobulin level with their socioeconomic factors and nutritional status. Thirty vitiligo patients were recruited randomly from the Department of Dermatology and Venereology, Bangabandhu Sheikh Mujib Medical University Hospital, Dhaka, Bangladesh for this study. Thirty healthy individuals as control group matched by age, sex, education and socioeconomic factors to the patient group were selected. Serum immunoglobulin concentrations were determined by turbidimetry method using immunoglobulin kit. The concentration of IgG and IgA decreased significantly (P<0.05), but the change of IgM was not significant. Socioeconomic data revealed that most of the patients were young and female. Moreover statistical analysis revealed that there was significant correlation between immunoglobulin (IgG and IgA only) concentrations and BMI and number of depigmented patches with IgG concentrations. Finally it can be concluded that the change of serum immunoglobulin concentration in vitiligo patients could be due to the disease condition as pathomechanism suggested the aberrations in cellular immunity. But study with larger number of population is required for further evaluation of the relationship between the immune response and disease state to confirm these findings.

Comparative analysis of serum manganese, zinc, calcium, copper and magnesium level in panic disorder patients.

The purpose of the study was to determine the serum concentration of trace elements of panic disorder patients and to find out the relationship between trace element levels and nutritional status or socio-economic factors. The study was conducted among 54 panic disorder patients and 52 healthy volunteers. Patients were recruited from Bangabandhu Sheikh Mujib Medical University by random sampling. Serum trace element concentrations were determined by flame atomic absorption spectroscopy (for Mg, Zn, Ca, and Cu) as well as graphite furnace (for Mn). Data were analyzed by independent t test, Pearson's correlation analysis, regression analysis, and ANOVA. The serum concentration of Mn, Zn, Ca, Cu, and Mg in panic disorder patients were 0.37 +/- 0.30, 0.67 +/- 0.20, 99.91 +/- 15.15, 0.83 +/- 0.23, and 21.14 +/- 3.72 mg/L, while those were 0.4163 +/- 0.2527, 0.86 +/- 0.3, 106.6073 +/- 18.6531, 0.8514 +/- 0.3646, and 21.37 +/- 2.03 mg/L in control subjects, respectively. The serum concentration of Zn decreased significantly (p = 0.001) in patient group. But the differences of the concentration of Mn, Ca, Cu, and Mg between patient and control group were not significant (p = 0.522, p = 0.065, p = 0.800, and p = 0.712, respectively). Socio-economic data reveal that most of the patients were very poor and middle aged. Mean BMIs of the control group (23.74 +/- 2.71 kg/m(2)) and the patient group (22.62 +/- 3.74 kg/m(2)) were within the normal range (18.5-25.0 kg/m(2)). There was no significant relationship between serum zinc level and BMI of patients (r = 0.038; p = 0.809). So the decreased level of serum zinc in panic disorder patients was not because of other reasons, but rather it may provide a prognostic tool for the diagnosis and treatment of this disease.

Effect of channeling agents on the release pattern of theophylline from kollidon SR based matrix tablets.

The purpose of the present study was to investigate the effect of channeling agent on the release profile of theophylline from Kollidon SR based matrix systems. Matrix tablets of theophylline using Kollidon SR which is plastic in nature were prepared by direct compression process. NaCl and PEG 1500 were used as channeling agents. Drug release study was evaluated for eight hours using USP 22 paddle-type dissolution apparatus using distilled water as the dissolution medium. The release mechanisms were explored and explained with zero order, Higuchi, first order and Korsmeyer equations. The release rate, extent and mechanisms were found to be governed by the type and content of the channeling agents. Increased rate and extent of the drug release were found by using higher content of channeling agent (42.49%) in the matrix due to increased porosity when compared with the formulation having no channeling agents. On the other hand decreased rate and extent of drug release were observed in the formulation having lower channeling agent content (19.76%). PEG 1500 ensures maximum release of drug from Kollidon SR than NaCl when other parameters were kept unchanged. It was found that type and amount of channeling agent significantly affect the time required for 50% of drug release (T50%), percentage drug release at 8 hours, release rate constant (K) and diffusion exponent (n). Kinetic modeling of dissolution profiles revealed drug release mechanism ranges from diffusion controlled or Fickian transport to anomalous type or non-Fickian transport, which was mainly dependent on the type and amount of channeling agents. These studies indicate that the proper balance between a matrix forming agent and a channeling agent can produce a drug dissolution profile similar to a desired dissolution profile.

Bioequivalence and pharmacokinetic study of two different omeprazole capsule formulations in healthy Bangladeshi volunteers.

Omeprazole (CAS 73590-58-6) effectively suppresses the gastric acid secretion in the parietal cells of the stomach and is a widely prescribed proton pump inhibitor in Bangladesh. The increasing number of omeprazole containing products available in the market raises questions of therapeutic equivalence and/or generic substitution which are yet to be conducted with Bangladeshi population. The aim of the study is to assess the bioequivalence and pharmacokinetic properties of two oral formulations of 20 mg omeprazole capsule, the reference product and Omep-20 as test product using serum data. The randomized, two-way crossover study was conducted on 24 healthy male subjects in compliance with the Declaration of Helsinki and ICH guidelines. Subjects were assigned to receive test and reference as a single dose of 20 mg capsule under fasting condition, following a washout period of one week. After oral administration, blood samples were collected at various time intervals and analyzed for omeprazole concentrations using a validated HPLC method. The pharmacokinetic parameters were determined by non-compartmental method. From serum data, the obtained values for test and reference products were 648.07 +/- 216.27 and 632.69 +/- 257.01 ng/ml for Cmax; 2012.24 +/- 634.48 and 1907.86 +/- 761.91 ng x h/ml for AUC0-24; 2105.21 +/- 623.79 and 1979.18 +/- 748.12 ng x h/ml for AUC0-infinity respectively. No statistically significant differences were observed between two formulations by analyzing different pharmacokinetic parameters in terms of period, sequence or formulation. From the paired t-test, no significant differences between two formulation were observed (p > 0.05). The 90% confidence intervals of Cmax, AUC0-24 and AUC0-infinity were found to be 91.59% to 122.60%, 101.86% to 116.78% and 102.77% to 116.68% respectively which are within the FDA accepted limits for bioequivalence (80%-125 %). Finally it can be concluded that both products are bioequivalent in terms of rate and extent of drug absorption and therefore interchangeable.

Theophylline loaded gastroretentive floating tablets based on hydrophilic polymers: preparation and in vitro evaluation.

This investigation describes the preparation and in vitro evaluation of gastroretentive floating tablet of theophylline. Two hydrophilic cellulose derivatives, Methocel K100M and Methocel K15MCR were evaluated for their gel forming and release controlling properties. Sodium bicarbonate and citric acid were incorporated as gas generating agents. The effects of soluble components (sodium bicarbonate and citric acid), gel forming agents and amount variation of theophylline on drug release profile and floating properties were investigated. Tablets were prepared by direct compression technique. Formulations were evaluated for in vitro buoyancy and drug release study was evaluated for eight hours using USP XXII paddle-type dissolution apparatus using 0.1N HCl as dissolution medium. The release mechanisms were explored and explained with zero order, first order, Higuchi and Korsmeyer equations. The release rate, extent and mechanisms were found to be governed by polymer and floating agent content. The content of active ingredient was also a vital factor in controlling drug release pattern. It was found that polymer content and amount of floating agent significantly affected the mean dissolution time, percentage drug release after 8 hours, release rate constant and diffusion exponent.

Zinc, manganese, calcium, copper, and cadmium level in scalp hair samples of schizophrenic patients.

The purpose of the study was to determine the concentration of trace elements present in scalp hair sample of schizophrenic patients and to find out the relationship between trace elements level and nutritional status or socioeconomic factors. The study was conducted among 30 schizophrenic male patients and 30 healthy male volunteers. Patients were recruited from Bangabandhu Sheikh Mujib Medical University by random sampling. Hair trace element concentrations were determined by flame atomic absorption spectroscopy and analyzed by independent t test, Pearson's correlation analysis, regression analysis, and analysis of variance (ANOVA). Mn, Zn, Ca, Cu, and Cd concentrations of schizophrenic patients were 3.8 +/- 2.31 microg/gm, 171.6 +/- 59.04 microg/gm, 396.23 +/- 157.83 microg/gm, 15.40 +/- 5.68 microg/gm, and 1.14 +/- 0.89 microg/gm of hair sample, while those of control subjects were 4.4 +/- 2.32 microg/gm, 199.16 +/- 27.85 microg/gm, 620.9 +/- 181.55 microg/gm, 12.23 +/- 4.56 microg/gm, and 0.47 +/- 0.32 microg/gm of hair sample, respectively. The hair concentration of Zn and Ca decreased significantly (p = 0.024; p = 0.000, respectively) and the concentration of Cu and Cd increased significantly (p = 0.021; p = 0.000, respectively) in schizophrenic patients while the concentration of Mn (p = 0.321) remain unchanged. Socioeconomic data reveals that most of the patients were poor, middle-aged and divorced. Mean body mass indices (BMIs) of the control group (22.26 +/- 1.91 kg/m(2)) and the patient group (20.42 +/- 3.16 kg/m(2)) were within the normal range (18.5-25.0 kg/m(2)). Pearson's correlation analysis suggested that only Ca concentration of patients had a significant positive correlation with the BMI (r = 0.597; p = 0.000) which was further justified from the regression analysis (R (2) = 44%; t = 3.59; p = 0.002) and one-way ANOVA test (F = 3.62; p = 0.015). A significant decrease in the hair concentration of Zn and Ca as well as a significant increase in the hair concentration of Cu and Cd in schizophrenic patients than that of its control group was observed which may provide prognostic tool for the diagnosis and treatment of this disease. However, further work with larger population is suggested to examine the exact correlation between trace element level and the degree of disorder.

Bioequivalence evaluation of two capsule formulations of amoxicillin in healthy adult male bangladeshi volunteers: A single-dose, randomized, open-label, two-period crossover study.

BACKGROUND: Amoxicillin, a semisynthetic penicillin antibiotic, is widely prescribed in Bangladesh due to its extended spectrum and its rapid and extensive oral absorption with good tolerability. Although a number of generic oral formulations of amoxicillin are available in Bangladesh, a study of the bioequivalence and pharmacokinetic properties of these formulations has not yet been conducted in a Bangladeshi population. OBJECTIVE: The aim of this study was to assess the pharmacokinetic properties and bioequivalence of 2 formulations of amoxicillin 500-mg capsules (test, SK-mox(®); reference, Amoxil-Bencard(®)) using serum data. METHODS: This single-dose, randomized, open-label, 2-period crossover study was conducted in healthy male subjects in compliance with the Declaration of Helsinki and International Conference on Harmonisation guidelines. Subjects were assigned to receive the test or the reference drug as a single-dose, 500-mg capsule under fasting conditions after a 1-week washout period. After oral administration, blood samples were collected and analyzed for amoxicillin concentration using a validated high-performance liquid chromatography method. The pharmacokinetic parameters were determined using a noncompartmental method. The formulations were considered bioequivalent if the natural log-transformed ratios of pharmacokinetic parameters were within the predetermined equivalence range of 80% to 125%, according to the US Food and Drug Administration (FDA) requirement. RESULTS: Twenty-four healthy adult male Bangladeshi volunteers (mean [SD] age, 26.92 [3.37] years; age range, 23-34 years; mean [SD] body mass index, 23.O9 [1.58] kg/m(2)) participated in the study. Using serum data, the values obtained for the test and reference formulations, respectively, were as follows: Cmax, 9.85 (2.73) and 10.63 (2.12) µg/mL; Tmax, 1.29 (0.58) and 1.33 (0.49) hours; and AUC0-12, 27.09 (7.62) and 28.56 (6.30) µg/mL · h(-1). No period, sequence, or formulation effects were observed; however, significant variation was found among subjects with regard to AUC0-12 (P < 0.001), AUC0-∞ (P = 0.002), area under the moment curve (AUMC) from 0 to 12 hours (P < 0.001), and AUMC0-∞ (P = 0.017). All CIs for the parameters measured were within the FDA-accepted limits of 80% to 125%. CONCLUSION: The present study suggests that the test 500-mg amoxicillin capsule was bioequivalent to the reference 500-mg capsule according to the FDA regulatory definition, in this population of healthy adult male Bangladeshi volunteers.