Will amoxicillin treat bronchitis

One group was treated with the reference standard (Amoxil ® ) and the other one with the generic tablet Amoxicare ® , with a crossover after a wash-out period of 7 days.

Blood samples were collected at fixed

time

C

max

two

Based on these findings it was concluded that the practice of interchangeability between the above formulations to achieve better patient compliance could be followed without compromising the extent of amoxicillin absorption. Wt: 365.41; ? max : 230-273.8 nm, ethanol; LogP: 0.91; fig. 1 ) is a commonly prescribed orally available ?-lactam antibiotic with moderate antibacterial spectrum that is available on the market as different dosage forms and in strengths.

For instance, it is available as 1000 mg tablet and as 500 mg capsules. The question of whether two 500 mg capsule can be substituted with one 1000 mg tablet is not uncommon and pharmacists face such problem frequently with many other prescribed medications.

Possible reasons for substitution include the following; (i) the prescribed original brand or the dosage is not available in pharmacy as the case in many developing countries, (ii) difference in the price of the prescribed dosage form and (iii) better swallowing characteristics especially for elderly patients. The later reason is of particular importance as swallowing problems can cause poor patient compliance.

In fact, some studies have indicated that some dosage forms are preferred over others by elderly patients.

For example, capsules are preferred over tablets when large amount of active ingredient is to be swallowed[1].

In fact, the rugged surface of some tablets may scratch the esophagus during intake[2]. Indeed, damage of esophagus by retention of tablet has been reported[3].

Furthermore, some tablets have strong smell or taste. All these factors may make the administration of tablets an uncomfortable experience leading to poor patient compliance.

In such cases, substitution of large volume tablet with two capsules containing the same drug strength can solve problems associated with swallow ability.

However, bioequivalence problems may arise especially when the substitution was carried out between liquid and solid oral dosage forms, or between soft elastic gelatin capsules and tablets[4]. On the other hand, bioequivalence cannot be compromised when two solid dosage forms such as hard gelatin capsules and tablets where interchanged. Few publications are found in literature demonstrating potential interchangeability of two different solid dosage forms based on pharmacokinetic data[5,6].

The aim of the present study was to determine if the practice of interchangeability between two amoxicillin capsules (Amoxil ® , 500 mg/capsule) and one amoxicillin tablet (Amoxicare ® , 1000 mg/tablet) in order to achieve better patient compliance can be conducted without compromising their extent of absorption.

Acetonitrile HPLC grade, methanol HPLC grade and tetra-n-butyl ammonium hydroxide were from Merck, (Darmstadt, Germany); chloroform HPLC grade was from Fisons Scientific Equipments, UK; sodium dihydrogen phosphate dihydrate (NaH 2 PO 4 ·2H 2 O) was from Riedel de Haen, (Seelze, Germany); double distilled high purity water was used. The HPLC grade solvents acetonitrile and methanol were used as received.

Amoxicillin and Paracetamol (internal standard) were supplied by Pharmacare Chemical and Cosmetics (Ramallah, Palestine). Amoxicare ® tablet (1000 mg amoxicillin/tablet, batch number RD-23E03) was from Pharmacare Chemical and Cosmetics.

Amoxil ® capsules (500 mg/capsule, batch number 040605) were manufactured by Medical Union Pharmaceuticals Co, Abou Sultan Egypt, under license of Beecham Pharmaceuticals Brantford England.

The protocol of the study was approved by the Ethical Committee of Tanta University Hospital (Tanta, Egypt). The whole study followed the requirements of the Declarations of Helsinki and was conducted in accordance with the current Good Clinical Practice (GCP), International Conference Harmonization (ICH) as well as Good Laboratory Practice (GLP) Guidelines.

Each volunteer had signed the informed consent form after ample information and consideration time has been provided.

Twenty-four adult male volunteers, non-smokers, aged between 17-30 y, weighing between 59 and 85 kg, were chosen to participate in the present study. The volunteers were not on concomitant medications and they were free from significant cardiac, hepatic, renal, pulmonary, gastrointestinal, neurological or hematological disease as determined within four weeks prior to the beginning of the study by way of medical histories and physical examinations.

Subject’s health status was determined following a physical examination, laboratory tests and medical history by a qualified registered MD physician. The physician reviewed all preclinical laboratory tests for each subject. Exclusion criteria included extreme weight ranges (overweight or underweight), anemia, liver or renal dysfunction, parasitic and other diseases or conditions that was judged to affect the absorption, distribution and/or elimination of amoxicillin.

The subjects were asked to abstain from taking drugs and alcohol for at least 3 days prior to the test and throughout the entire study period.

However, it has to be underlined that the drugs eventually used by the involved volunteers are characterized by short half life values and thus do not overlap with amoxicillin during the first day of study.

On the night before starting the study, the volunteers were instructed to fast for at least 10 h before drug administration.

The study had an open randomized two-period crossover design with a 7-day washout period between doses. The volunteers were randomly divided into two equal groups each of 12 subjects.

The first group was given the reference formulation and the second group received the test formulation with a crossover after a washout period of one week.

On the morning of the experiment, 10 ml of blood sample was withdrawn from each volunteer to serve as a blank for the drug assay. Each of the 24 volunteers then took one Amoxicare ® tablet (1000 mg amoxicillin) as the test drug or two Amoxil ® capsules (500 mg amoxicillin each) as the reference

drug

Samples were obtained at 0.0 (blank sample), 0.25, 0.5, 0.75, 1, 1.5, 2, 2.5, 3, 4, 6, 8 h after drug administration, in heparinized tubes.

Plasma was directly separated by centrifugation at 3000 rpm for 10 min and stored at -20° until analyzed.

Four hours after drug administration, the subjects were allowed to eat a standard breakfast of bread, jam, low-fat white cheese, water (150 ml).

They were then allowed controlled access to fruit juice and other non-alcoholic beverages.

The volunteers had their second meal (standard lunch containing grilled chicken, rice and vegetables) 4 h later. Stock solution of amoxicillin (500 µg/ml) was prepared by dissolving 50 mg of drug in methanol. Working standard solutions were prepared from the stock solution by serial dilution with methanol to prepare seven working solutions of amoxicillin with concentrations of 5, 10, 20, 50, 100, 200 and 500 µg/ml.

Stock solution of paracetamol (internal standard) was prepared by dissolving the drug powder in methanol to give 50 µg/ml.

Stock and working standard solutions were protected from light and stored at -20° until use. The calibration standards were prepared by adding known amounts (50 µl) of amoxicillin to each working solution, and 50 µl of the internal standard solution to a set of clean test tubes. After evaporation of the methanol solution 0.5 ml of blank

plasma

The supernatant was transfered to clean test tube and 5 ml of chloroform was added, shacked for one minute, and then centrifuged at 3000 rpm for 7 min. The upper layer was separated and 50 µl was injected into the HPLC column. For the analysis of the samples, 0.5 ml of each study sample was transferred to a clean test tube spiked with the internal standard. The study samples were treated as the calibration standards after addition of the internal standard. Under the chromatographic conditions described above, the retention time of amoxicillin and the internal standard (paracetamol) were 4.8±0.5 and 6.0±0.5 min, respectively.

Analytical validation report for HPLC method used for the quantification of amoxicillin in human plasma is described below.

The analyses were performed using an HPLC system equipped with a variable wavelength UV detector and an automatic injector was used in this study Waters 2690 Separation Modules, Waters Corporation, Milford Massachusetts, USA. Separation was accomplished with a 250?4.6 mm 5 µm Hypersil ® BDS C 18 column, Thermo Fisher Scientific Inc, Waltham, United States. The mobile phase used consists of 94% buffer and 6% acetonitrile, where buffer is a mixture of tetra-n-butyl ammonium hydroxide (0.15 g/l) in sodium dihydrogen phosphate dehydrate (20 mM). The flow rate was 1.2 ml/min, the UV

detector

Calibration curves were constructed from the peak area ratio (drug/ internal standard) and the corresponding amoxicillin concentration in each calibration standard. The linearity study was carried out in the range of concentrations between 0.5 to 50 µg/ml.

To assess linearity, drug free plasma

was

The correlation coefficient was always greater than 0.99 during the course of the validation. METHOD VALIDATION PARAMETERS OF AMOXICILLIN ANALYSIS. Parameters Results Linearity range 0.5-50 mg/ml Correlation coefficient 0.9978 Regression equation (y=mx+q) m 0.208 c 0.056 Limit of quantitation (LOQ) 0.5 µg/ml Coefficient of variation intraday (%CVintra) (n=3) from 0.735 to 13.38% Coefficient of variation inter-day (% CVinter) (n=3) from 0.783 to 13.13% Accuracy intra-day (%) from 95 to 109% Accuracy inter-day (%) from 93 to 112% Precision was determined as the coefficient of variation (CV), and the accuracy as the percentage relative error (RE) of a series of measurements. Precision and accuracy data were obtained by analyzing aliquots of three-spiked plasma at low middle and high concentration levels of amoxicillin.

Intraday reproducibility was determined by analyzing three replicates of calibration curves on the same day, and inter-day reproducibility was evaluated by the analysis of six different calibration curves on six different days during the study period. The intraday coefficient of variation

and

The accuracy of the method was validated as the intra-day accuracy was in the range from 95 to 109% and the inter-day accuracy was in the range of 93 to 109% during the entire period in which calibration curves were generated.