Brands Of Tablets Research Articles

Comparative evaluation of the biopharmaceutical and chemical equivalence of some commercially available brands of ciprofloxacin hydrochloride tablets

Purpose: This study was undertaken with the objective of evaluating the biopharmaceutical equivalency of ten brands of ciprofloxacin tablets and the chemical equivalency with the use of an analytical method, which will be easy to use, accurate, reproducible, simple, and inexpensive. Method: The biopharmaceutical and chemical equivalence of ten brands of ciprofloxacin hydrochloride tablets were assessed through the evaluation of the uniformity of weight, friability test, hardness, disintegration test, dissolution rate, thin layer chromatography and non-aqueous titration procedure with the use of crystal violet solution indicator. Result: All the brands complied with the official specification for uniformity of weight and friability test, while one of the brands failed the disintegration test. The dissolution rate profile revealed that four of the brands did not attain 70% dissolution throughout the period of the determination, while the other brands had above 70% dissolution at less than 45minutes. The non-aqueous titrimetric procedure showed that the excipients did not affect the procedure; with seven brands having values within the range specified in the USP, while the remaining three brands gave lower values. Conclusion: Six of the brands evaluated in this study could be regarded as being biopharmaceutically and chemically equivalent, while a particular brand is obviously a fake product. The non-aqueous titrimetric procedure used in this study is simple, inexpensive, and easy to use and could be used in routine monitoring of the quality of ciprofloxacin HCl tablets, especially in the absence of high technology equipments that are not easily available in most developing countries. Keywords : Ciprofloxacin hydrochloride tablets, non-aqueous titration, chemical equivalence, biopharmaceutical equivalence > Tropical Journal of Pharmaceutical Research Vol. 6 (3) 2007: pp. 737-745

Pharmacokinetics of an extended-release theophylline product in cats

To evaluate the pharmacokinetics of a brand of extended-release theophylline tablets and capsules in healthy cats. Randomized 3-way crossover study. 6 healthy cats. A single dose of aminophylline (10 mg/kg [4.5 mg/lb], IV), a 100-mg extended-release theophylline tablet, or a 125-mg extended-release theophylline capsule was administered to all cats. Plasma samples were collected via preplaced central catheters throughout a 36-hour period. Plasma samples were frozen until analyzed by use of a fluorescence polarization monoclonal immunoassay. All cats tolerated drug administration and plasma collection with no adverse effects. Peak concentrations were reached for both orally administered products between 8 and 12 hours after administration. Bioavailability was excellent. Plasma concentrations were within the human therapeutic concentration of 5 to 20 microg/mL. Daily administration of the brand of theophylline tablets and capsules used in this study at 15 mg/kg (6.8 mg/lb) and 19 mg/kg (8.6 mg/lb), respectively, maintained plasma concentrations within the desired therapeutic range in healthy cats.

Simple and Rapid Liquid Chromatographic Method for Determination of Histidine HCl in Pharmaceutical Preparations

Histidine (HID) is frequently compounded in pharmaceutical preparations for the treatment of gastrointestinal diseases. A simple and rapid liquid chromatographic method was developed and validated for the routine determination of HID in pharmaceutical preparations. The high-performance liquid chromatographic (HPLC) system consisted of an Purospher STAR RP18 endcapped column (4.6×250 mmi. d.) using amobile phase of 50 mMphosphate buffer with 3 mM sodium octanesulfonate: acetonitrile (95:5, v/v) with an ultraviolet/visible (UV/VIS) detector at 210 nm. The developed method satisfies the system suitability criteria and peak integrity for HID. The square of the correlation coefficient of the linear regression analysis was 0.9995. The relative standard deviations (RSDs) for intra- and inter-day tests were less than 2%. The recovery for 5 concentrations expressed as the closeness of the observed mean to the spiked concentration was 98.20%~101.02%. The limits of detection (LOD) and quantitation (LOQ) for HID were 2.2 and 7.3 μg/mL, respectively. The method was applied to quantitatively determine HID in 8 brands of HID-containing tablets on the Taiwanese market, and these were found to contain 100.59%±1.01% of the percentage claimed on the label. The results indicate that the established assay method is suitable for measuring HID in pharmaceutical preparations.

Quality control assessment and the possibility of interchangeability between multisourced norfloxacin tablets marketed in Nigeria

Quality control assessment of four brands of norfloxacin tablets marketed in Nigeria was carried out in enzyme-free simulated intestinal fluid (SIF) and simulated gastric fluid (SGF) with the aim of selecting brands that are interchangeable. The possible in vivo bioavailabilities of the brands were predicated based on their respective dissolution efficiency (DE) and predicted availability equivalent (PAE). The results of weight uniformity test, disintegration time test and other non-pharmacopoeia tests of all brands were within the acceptable ranges. Predictions from DE indicated that the brands were all bioequivalent and therefore interchangeable with the innovator brand. The concept of dissolution efficiency (DE), in vitro dissolution studies could serve as a rapid means of comparing brands of norfloxacin tablets. Key words: Norfloxacin, interchangeability, quality control, dissolution efficiency, predicted availability equivalent.

Brnd variations in the physicochemical properties of metronidazole tablets

This study investigated possible variations in the physiochemical properties of seven brands of metronidazole tablets obtained from different retail pharmacy outlets in Nigeria. The different brands were subjected to various tests such as uniformity of weight, crushing strength, friability, disintegration and dissolution. Chemical assays were also carried out on the tablets. Five of the seven brands of metronidazole tablets passed all British Pharmacopoeia tests; while brand G failed the chemical assay test and brand A failed both the chemical assay and test for friability. Brand A also had the lowest crushing strength which was below the recommended minimum. There was a significant difference (p < 0.001) in the values obtained for the crushing strength of the various brands while no significant difference (p > 0.05) in the friability values. The results show that five of the seven brands are physically and chemically equivalent and could be interchanged irrespective of the brands, while two cannot. The study reinforces the need for constant monitoring of different brands of the same product to ensure quality and consequent efficacy.

Paracetamol Bioavailability Study by Means of Salivary Samples

Bioequivalence of two different marketed paracetamol tablets, Decamol (500 mg, B.N., 4151, Megapharm) and Otamol (500 mg, B.N, 41093, Al-Quds-pharm), were compared to the innovator product, Dexamol (500 mg, B.N.12603, Dexxon). The bioavailability study was carried out in healthy volunteers in a crossover sequence using saliva drug levels as a parameter. In vitro studies, it was shown that all three products, Decamol, Otamol and Dexamol, were pharmaceutically equivalent. The bioavailability data obtained could be correlated to the in vitro data of the three tablet brands. In vivo investigations indicated no statistically significant differences in the bioavailability of Decamol and Otamol from Dexamol tablets. Therefore, all the three products are considered bioequivalent.

A Comparison of the Technical Quality of American and Japanese Ranitidine Tablets

The purpose of this study was to compare the technical quality of commercial American and Japanese ranitidine tablets. Five brands of 150-mg USP tablets and six brands of 150-mg JP tablets were compared on hardness, friability, average weight, average content, content uniformity, and dissolution. The difference in hardness between American and Japanese tablets was significant. Dissolution profiles of Japanese tablets were not significantly different from one other, whereas those of American tablets were significantly different. However, all brands complied with USP 27. Since all brands can be expected to be in therapeutic use, this result supports the use of the USP criterion as an indicator for therapeutic efficacy.

Perbandingan Mutu Dan Harga Tablet Amoksisilin 500 Mg Generik Dengan Non Generik Yang Beredar Di Pasaran

Amoxiciilin is an antibiotic of penicillin. It has been used to treat bacterial infections that caused by Gram negative bacteria and Gram positive bacteria. Most of amoxicillin tablet has been sold with generic name and non generic name. This research was proposed to compare quality and price of amoxicillin tablet 500 mg at the drug store. Especially, for amoxicillin tablet 500 mg generic and non generic. Determination of quality amoxicillin tablet could be showed from standard quality of amoxicillin tablet was based at USP XXVI. Identification, dissolution and assay were included standard quality of amoxicillin tablet. Identification test was performed by TLC with mobile phase consist of methanol, chloroform, water and pyridine (90:80:30:10). Assay of dissolution test was performed by HPLC with mobile phase potassium dihydrogen phosphate buffer and acetonitrile (39:1). Assay of tablet was performed by HPLC with mobile phase potassium dihydrogen phosphate buffer and acetonitrile (96:4). The experiment was held to 15 brands of tablet which they had consisted 3 brands of generic tablet and 12 brands of non generic tablet. The test resulted that every brands of tablet fulfilled standard quality of amoxicillin tablet. But in the test, there was variation of price, in ordinarily price of non generic tablet was more expensive than generic tablet.

The frequency of inappropriate tablet splitting in primary care

We assessed the frequency and determinants of tablet splitting in primary care in Germany and evaluated the quality of information on divisibility in the Summary of Product Characteristics (SPCs) and in the Package Leaflet (PL) as legal sources of information for health care providers and patients. We performed a cross-sectional questionnaire survey among patients of 59 general practitioners in the German Federal State Saxony-Anhalt in 2005 in order to collect detailed information on all drugs of patients maintained on more than three drugs. The response rate was 82.1% (n=905) and 3,158 drugs (tablets and dragées) were included in the analyses. Of all drugs, 24.1% were split (762 of 3,158): 8.7% of all split tablets were unscored (66 of 762) and 3.8% of all split tablets were not allowed to be split (29 of 762). Tablets of the higher price categories and higher strengths were twice as likely to be split. Only 22.5% of the SPCs (9 of 40) of the split unscored tablet brands contained explicit information on divisibility and only 36.4% of the PLs (8 of 22) of the split brands that were not allowed to be split stated that splitting was not appropriate. The splitting of tablets in primary care is a frequent habit likely driven by medical and economic considerations. Almost 1% of all tablets are split that must not be fragmented. However, the SPC and PL provide only limited information on divisibility stressing the need to improve this information promptly to avoid medication errors.

Investigation of Goats??Milk Adulteration with Cows??Milk by PCR

Goats' milk adulteration with cows' milk is becoming a big problem. In the past, the urea-polyacrylamide gel electrophoresis assay with different motility of αS1-casein has been applied for the identification of cows' milk adulteration. The detection sensitivity is 1.0%. The aim of this study was to develop a faster and more sensitive method to detect cows' milk which may be present in adulterated goats' milk and goats' milk powder. The published primer was targeted at highly conserved regions in bovine mitochondrial DNA (a 271 bp amplicon). This amplicon was cloned and sequenced to further confirm bovine specific sequence. The chelex-100 was used to separate bovine somatic cells from goats' milk or goats' milk powder samples. Random sampling of different brands of goats' milk powder and tablets from various regions of Taiwan showed the adulterated rate was 20 out of 80 (25%) in goats' milk powders and 12 out of 24 (50%) in goats' milk tablets. With this system, as low as 0.1% cows' milk or cows' milk powder in goat milk or goat milk powder could be identified. This chelex DNA isolation approach provides a fast, highly reproducible and sensitive method for detecting the adulteration of goats' milk products.

Comparative analysis of lamivudine in two commercially available brands using HPLC and UV-VIS spectroscopy

One of the components of care for people living with HIV/AIDS is the use of antiretroviral drugs (ART) and the successful outcome of these drugs requires proven quality, safety and efficacy. The quality of these drugs can be assessed by qualitative and quantitative analysis using different analytical techniques. The objective of this study is to compare the analytical results of two brands of ART drug, Lamivox-150 and Lamidine using high pressure liquid chromatography (HPLC) and UV spectroscopy in order to select a validated, simple, cost-effective and affordable analytical technique. The two brands of a lamivudine tablets were quantified against a reference standard, lamivudine with HPLC and UV spectroscopy and the results were compared. The HPLC method involves the use of methanol:acetonitrile (5:95) as a mobile phase, and octadecylsilane (C18) as a stationary phase. For UV spectroscopic analysis, complete release of the active ingredient from the tablets was achieved with 0.01N HCl using ultrasonic bath for 10 min. This is followed by subsequent quantitative determination of the released drug at maximum absorbance wavelength of 280 nm. Concentrations of lamivudine ranging from 0.2-2 mg/ml and 1.6-16 µg/m were used to construct calibration curves for HPLC and UV spectroscopic analyses, respectively. The content of lamivudine per tablet in Lamivox-150 and Lamidine was found to be in agreement with the labelled amount when analysed by both techniques (p

Bioequivalence assessment of the two brands of glimepiride tablets

Glimepiride, as an antidiabetic from the group of sulfonylurea, is administered perorally in the treatment of diabetes mellitus. The aim of this study was to compare pharmacokinetic profiles and relative bioavailabilities of the two oral formulations of glimepiride, generic and innovator tablets, after a single dose of the active drug. An oral dose of 6 mg glimepiride was given under fasting conditions to 24 healthy volunteers. A one-week washout period was applied between the two consecutive periods. The serum samples obtained before dosing, and at various time points up to 48 hours, were analyzed for glimepiride concentration using the validated high-performance liquid chromatographic method with ultraviolet detection. Pharmacokinetic parameters representing early (maximal concentration, time to reach maximal concentration) and total exposure (area under the curve from the time 0 to the infinite time) to glimepiride were obtained and further analyzed using the multifactorial analysis of variance and the non-parametric Wilcoxon signed ranks test. Comparison of the secondary kinetic variables was only descriptive. The point estimates of the ratios of geometric means (test/reference) of maximal concentrations and areas under the curve were 1.046 (90% confidence interval: 0.906-1.208) and 1.022 (90% confidence interval: 0.856-1.220), respectively, while the median values of times to reach maximal concentration, at 5% level of significance, did not differ significantly. Both formulations were well tolerated. Transient mild hypoglycaemia, which had been noted in 6 participants, resolved spontaneously within 30-60 minutes. Since all the parametric 90% confidence intervals for the log-transformed main variables of glimepiride were within the 0.80 and 1.25 interval, accepted as the definition of bioequivalence, and the differences in times to reach maximal concentration also did not reach statistical significance, studied tablets were considered bioequivalent.

The chemical and pharmaceutical equivalence of sulphadoxine/pyrimethamine tablets sold on the Tanzanian market

This study investigated chemical and pharmaceutical equivalence of 11 brands of pyrimethamine-sulphadoxine combination tablets sold on the Tanzanian market. Physical and chemical tests were performed for all the 11 brands. These tests included hardness test, friability, disintegration, dissolution, weight uniformity and assay for the active components. All the brands passed all the quality specifications of the United States Pharmacopoeia (USP) and British Pharmacopoeia (BP) in terms of hardness, friability, disintegration, assay and dissolution test, except for three brands that failed the hardness, disintegration or friability tests. One brand failed both the hardness and disintegration test; one failed the hardness test, whereas another one failed the friability test. The percentage content of pyrimethamine in the brands was in the range of 91.04-100.20% whereas that of sulphadoxine ranged from 91.53% to 99.88%. There were no major differences between the different brands of tablets containing pyrimethamine and sulphadoxine and the innovator product (Fansidar), and all brands were physically and chemically equivalent. The results indicate that the post-market surveillance and registration process in Tanzania is having an impact on product quality as there was no brand which could be considered of very poor quality. Impurity profiling of all the locally produced brands indicated that they all contained the same sulphadoxine impurity, which was absent in the innovator product, suggesting a common source of generic raw material.

Quality assessment of some brands of Ciprofloxacin tablets on sale in Abuja, Nigeria

The quality of the various brands of ciprofloxacin tablets in circulation within Abuja, the Federal Capital City of Nigeria, was assessed. Spectrophotometric evaluation showed that all the brands contained a chemical equivalent of ciprofloxacin within the limits of the official specification. However their antimicrobial activity as indicated by the zone of inhibition was less than that of the reference standard. Three of the ten samples tested failed the disintegration and dissolution tests as specified by the British Pharmacopoeia for film coated tablets. Key words: Ciprofloxacin; Quality assessment; Spectrophotometric evaluation; Microbial potency Journal of Pharmacy and Bioresources Vol. 2 (1) 2004: 49-54

Bioequivalence evaluation of two brands of meloxicam tablets (promotion® and mobicox®): pharmacokinetics in a healthy female Mexican population

We conducted a randomized, crossover study in 23 healthy young female volunteers to compare the bioavailability of two brands of meloxicam (7.5 mg) tablets and to obtain pharmacokinetic parameters of this molecule in Mexican population not reported previously. Two tablets (15 mg) were administered as a single dose on 2 treatment days separated by a 1-week washout period. After dosing, serial blood samples were collected for a period of 72 h. Plasma harvested was analyzed for meloxicam by a modified and validated high-performance liquid chromatography (HPLC) method previously reported. Pharmacokinetic parameters AUC(0-t), AUC(0-alpha), C(max), T(max), k(e), MRT and t(1/2) were determined from plasma concentrations of both formulations, resulting in a C(max) 120% larger than and a T(max) 65% faster than those reported in other populations. AUC(0-t), AUC(0-alpha), and C(max) were statistically tested for bioequivalence after log transformation data in a non-balanced design, and no significant differences were found either in 90% classical confidence interval (90% CI) or in Schuirmann test (p < 0.05); thus, we concluded that bioequivalence existed between both formulations.

Pharmacokinetic Profiling and Bioequivalence Evaluation of 2 Lamivudine Tablet Formulations After Single Oral Administration in Healthy Human Indian Volunteers

The present study compared pharmacokinetic (PK) profile and single-dose tolerability of 2 marketed brands of lamivudine (3TC) 150-mg tablets, Lamivir (Cipla, Mumbai, India) and Epivir (GSK, Basingstoke, UK). The randomized, 2-treatment study was conducted in 24 fasting, healthy, Indian male subjects. Each subject received Epivir and Lamivir formulation separated by 7 days of drug-free washout period. Plasma concentrations of 3TC were used to estimate PK parameters such as maximum observed plasma concentration (Cmax) and area under plasma concentration-time curve (AUCinfinity). Geometric mean ratios (relative to Epivir) and resultant 90% CI of 3TC for Cmax and AUCinfinity were 1.00 (0.89-1.12) and 1.01 (0.94-1.07), respectively. As 90% CIs were entirely within 0.80-1.25 for log-transformed data, the 2 formulations were considered bioequivalent in the extent (AUCinfinity) and rate of absorption (Cmax and time to Cmax [tmax]). The means of primary PK parameters of 3TC, Cmax, and AUCinfinity in Indian subjects were comparable to those previously reported in the literature. Both formulations exhibited similar tolerability under fasting conditions.

Bioequivalence evaluation of two brands of lisinopril tablets (Lisotec and Zestril) in healthy human volunteers

The bioequivalence of two brands of lisinopril 20 mg tablets was demonstrated in 28 healthy human volunteers after a single oral dose in a randomized cross-over study, conducted at ACDIMA Center for Bioequivalence and Pharmaceutical Studies, Amman, Jordan. Reference (Zestril, AstraZeneca, UK) and test (Lisotec, Julphar, UAE) products were administered to fasting volunteers on 2 treatment days separated by a 2-week washout period; blood samples were collected at specified time intervals, and the plasma was separated and analysed for lisinopril using a validated LC-MS/MS method at ACDIMA Laboratory. The pharmacokinetic parameters AUC(0-t), AUC(0- proportional), C(MAX), T(MAX), T(1/2) and the elimination rate constant were determined from the plasma concentration-time profiles for both formulations and were compared statistically to evaluate bioequivalence between the two brands, using the statistical modules recommended by the FDA. The analysis of variance (ANOVA) did not show any significant difference between the two formulations and 90% confidence intervals fell within the acceptable range for bioequivalence. Based on these statistical inferences it was concluded that the two brands exhibited comparable pharmacokinetic profiles and that Julphar's Lisotec is bioequivalent to Zestril of AstraZeneca, UK.

Chemical Stability of Extemporaneously Prepared Lorazepam Suspension at Two Temperatures

The objective of this study was to determine the chemical stability of extemporaneously prepared lorazepam suspension (1 mg/mL) stored at two temperatures (4°C and 22°C) for 3 months. Lorazepam tablets marketed by two manufacturers (Mylan Pharmaceuticals and Watson Laboratories) were used to extemporaneously formulate two independently prepared suspensions. Each suspension was prepared using sterile water, Ora-Plus(®) and Ora-Sweet(®) to achieve a final concentration of 1 mg/mL. The two brands of tablets required different volumes of vehicles to prepare a pharmaceutically optimal suspension. The suspensions were stored in amber glass bottles at 4°C and 22°C for 91 days. Samples were analyzed by high performance liquid chromatography at baseline and on days 2, 3, 7, 14, 21, 28, 42, 63, and 91. The suspensions were considered stable if the mean lorazepam concentration remained greater than 90% of the initial concentration.The chemical stabilities of these two extemporaneously prepared lorazepam suspensions were comparable throughout the study. Both lorazepam suspensions were stable for 63 days when stored at 4°C or 22°C, and both were stable for 91 days when refrigerated at 4°C. When stored at room temperature, the suspension prepared from the Watson tablet retained 88.9 ± 1.4% of the initial concentration on day 91 and was therefore considered unstable, while the suspension prepared from the Mylan tablet was stable for the entire 91-day study.

Bioequivalence study of two formulations of enalapril, at a single oral dose of 20 mg (tablets): A randomized, two-way, open-label, crossover study in healthy volunteers

Background: Enalapril maleate is the monoethyl ester prodrug of enalapril- at, an angiotensin-converting enzyme inhibitor indicated in the management of essential and renovascular hypertension, and in the treatment of congestive heart failure and in asymptomatic patients with left ventricular dysfunction and an ejection fraction of ≥35%. Enalapril has little pharmacologic activity until hydrolyzed in vivo to enalaprilat. Objective: The aim of the present study was to compare the bioavailability and tolerability of 2 commercial brands (test and reference formulations) of enalapril tablets (20 mg), described as the rate and extent of absorption of the active moiety, to assess their bioequivalence. Methods: This single-dose, randomized, 2-way, open-label, crossover study in healthy volunteers aged 18 to 40 years was conducted at the Clinical Pharmacology Study Unit, Hospital Clínico San Carlos (Madrid, Spain). Subjects were randomized to receive (under fasting conditions) either the test or reference formulation of enalapril (20-mg tablet) at study period 1 and the opposite formulation at study period 2. Study periods were separated by a washout period of at least 7 days. During each study period, 15 plasma extractions were made to determine enalapril and enalaprilat plasma concentrations and to calculate the pharmacokinetic (PK) properties (maximal plasma drug concentration [C max], time to C max [T max], area under the plasma concentration-time curve [AUC] to the last measurable concentration [AUC t], AUC from time 0 to infinity [AUC 0−∞], mean residence time, and elimination half-life [ t l 2 ]) of both. Physical examination, subject interview, laboratory analyses, electrocardiogram, and blood pressure (BP) were used to assess tolerability. Results: Twenty-four subjects were included in the study (12 men, 12 women; mean [SD] age, 22.8 [2.2] years [range, 19–30 years]). Of these, 1 subject (4.2%) withdrew from the study for personal reasons; thus, PK and statistical analyses included results from 23 subjects. No statistically significant sequence or period effect was found. T max was not statistically different between the 2 formulations, and the 90% CI calculated for T max for the difference of the medians was within the predefined range. The 90% CIs of the logarithmically transformed concentration-derived parameters (C max AUC t, and AUC 0−∞) also were within the predefined range; thus, the 2 formulations are considered bioequivalent. For both formulations, systolic and diastolic BPs showed significant reductions compared with baseline values (P < 0.05). Seven adverse effects were recorded, all of them transient and none of severe intensity. Conclusions: In this study of 2 commercial brands (test and reference formulations) of enalapril in healthy subjects, designed and conducted under Good Clinical Practice guidelines, a similar rate and extent of absorption for both formulations were found to be bioequivalent. Both formulations produced a significant decrease in BP values and were generally well tolerated.

Bioequivalence and tolerability study of two brands of clopidogrel tablets, using inhibition of platelet aggregation and pharmacodynamic measures

Background The role of platelets in acute cardiovascular atherothrombotic events has been well established and attention has focused on platelet inhibition therapy. Clopidogrel is a novel thienopyridine inhibitor of adenosine diphosphate–induced platelet activation. Recent studies have shown that in the setting of coronary angioplasty/stenting, a loading dose of 300 mg followed by 75 mg once daily is required for optimum benefit. Objective This study assessed the bioequivalence and tolerability of 2 oral formulations of clopidogrel 75-mg tablets. Methods This 10-day, open-label, randomized, parallel-group, comparative bioequivalence and tolerability study was carried out in the Department of Clinical Pharmacology and Therapeutics, Nizam's Institute of Medical Sciences (Hyderabad, India). Young healthy male volunteers were enrolled. Subjects were randomized to receive one of two 75-mg tablet formulations of clopidogrel (Clopivas ® [test formulation] or Plavix ® [reference formulation]). Subjects first received a 300-mg loading dose (four 75-mg tablets) on day 1, followed by 75 mg (1 tablet) at 8:00 AM daily for the next 6 days. Inhibition of platelet aggregation, which is the pharmacologic basis for the therapeutic efficacy of antiplatelet agents, and the effect on bleeding time were used as the pharmacodynamic assessment criteria. Pharmacodynamic variables included mean of maximum activity of percentage of inhibition of platelet aggregation (E max), mean time to reach E max (t max), and mean area under the activity–time curve from time 0 to 168 hours (AUC 0–168). Tolerability assessments included blood pressure and heart rate measurements before and at regular intervals (every hour for 12 hours and then at 24 hours) over a 24-hour period after drug administration. Clinical tolerability was assessed using adverse effects, platelet count (assessed on days 3, 6, and 10 after first-dose administration), and neutrophil count (assessed on day 10 after first-dose administration). Results Twenty subjects were enrolled (mean [SD] age, 26.5 [2.9] years [range, 22–32 years]). E max, t max, and AUC 0–168 were similar between the 2 groups, as was bleeding time. The 90% CIs were within the bioequivalence acceptance range of 80% to 125%. One subject (10%) in the Plavix group experienced mild headache; no serious adverse effects were reported, and none of the subjects dropped out due to an adverse effect. Platelet and neutrophil counts were found to be within normal limits. Conclusions In this study of healthy male volunteers, the 2 tablet preparations of clopidogrel showed bioequivalence. However, the sample size was smaller than that generally recommended for a bioequivalence study, and additional studies with larger sample sizes are needed.