Erythromycin enteric-coated tablets to Release Study on
【Abstract】 Objective to erythromycin enteric-coated tablets
release rate determination of three methods for systematic study and comparison, and to establish its optimal
determination. Method of accounting for tons of hydrogen were used mouth alcohol chromogenic method, sulfuric acid color method, as well as high-performance liquid chromatography to erythromycin enteric-coated tablets release rate, for each
method to the study methodology and validation. The results using three methods may accurately determine the manner of the release rate of erythromycin enteric-coated tablets, the
results measured in different ways with little difference. Conclusion sulfuric acid color method for reagent easy to get, easy to operate, fast, accurate, as the best determination.
Key words Dirithromycin
Study on methods for the release determination of dirithromycin enteric ? coated tablets
ABSTRACT Objective Three methods by which the release of dirithromycin enteric-coated tablets were determinated and compared. Methods Xanthydrol coloring method, sulfuric acid
coloring method, and HPLC method were developed for determination of the release of dirithromycin enteric-coated
tablets. Result All of these methods can be used to determine the samples precisely, and difference of the results among
them is slightly. Conclusion Sulfuric acid coloring method is inexpensive, simple, rapid and precise, and it is regarded as the optimal method.
KEY WORDS Dirithromycin; Enteric-coated tablets; Release
Dirithromycin (dirithromycin) is a new type of second-
generation macrolide antibiotic erythromycin from erythromycin ring amine and fatty acid aldehyde condensation formed. Dirithromycin peptides by blocking the process of transfer of bacteria, inhibiting bacterial protein synthesis. In vitro of
erythromycin on the clinical evidence in a variety of common pathogenic bacteria have antibacterial effect. To erythromycin and erythromycin with a similar antibacterial spectrum, which is characterized by an excellent pharmacokinetic properties, half-life of up to 20 ~ 50h, adverse reactions are relatively mild [1,2]. Lilly's products in the United States in September 1993 in Spain, listed by the U.S. FDA approval in 1996, and income the United States Pharmacopoeia USP23. Currently there are several developed to erythromycin enteric-coated tablets
and enteric-coated capsules produced and approved for clinical use. Erythromycin enteric-coated tablets for the land release
rate determination method, the United States Pharmacopoeia (USP23) in the mouth accounted for tons of hydrogen used
alcohol chromogenic method ; China's pilot drug standards using sulfuric acid color method; In addition, you can also using the HPLC assay method for determination of drug release . We have these three methods were carried out
methodological studies, and the results measured by three methods were compared.
An instrument and reagent
ZRS-8 Intelligent Dissolution Tester (Tianjin University Radio Factory); Shimadzu UV-2401PC UV - visible
spectrophotometer; Shi-madzu high-performance liquid
chromatography (LC-10ATvp pump, SPD-10Avp visible UV detection
device, SCL-10Avp controller); AE200 electronic balance (Mettler - Toledo Instruments Shanghai Co., Ltd.).
Dirithromycin reference substance (purity 99.83%) was made by the Chinese pharmaceutical and biological products calibration; to erythromycin enteric-coated tablets (Size:
0.25g) as a self-made products; 10% of the population
accounted for tons of hydrogen to buy alcohol methanol
solution Since the Beijing Hengye Zhongyuan Chemical Co., Ltd.; acetonitrile, methanol for chromatography pure; hydrochloric acid, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, sodium hydroxide and sulfuric acid were of
2 Methods and Results
Alcohol accounted for 2.1 tons of hydrogen chromogenic method
Accounted for tons of hydrogen in the use of mouth alcohol chromogenic determination of the process of this product release rate found in full accordance with USP23 in
the color conditions, methods of linear and poor tolerability; improved color conditions, can method has more good linearity and color stability. Other conditions, such as the concentration of reference substance solution and the
detection wavelength, etc. are in the same conditions with the USP23.
2.1.1 United States Pharmacopoeia in terms of precision the amount of color to take under test solution, 0.50ml, adding 0.50ml acetic anhydride, mixing. Then add 5.0ml glacial
acetic acid, put it aside for 5min, account for tons of hydrogen by adding 0.50ml mouth alcohol test solution, placed so that the color 30min.
2.1.2 improved conditions for precise amount of color to take under test solution 1.0ml, adding 0.10mol / L
hydrochloric acid 4.0ml, shake, plus alcohol test solution population accounted for tons of hydrogen 10.0ml, mixing, heating in boiling water for 5min, Yu Bing bath cooling, and then placed at room temperature for 15min.
I account for tons of hydrogen-alcohol test solution was
prepared to take 10% of the total tons of hydrogen mouth alcohol methanol 0.02ml, home 100ml Liang Ping, the ice 20ml acetic acid and hydrochloric acid 1ml, shake, using glacial acetic acid diluted to the scale.
2.1.3 Preparation of standard curve said precision reference standards appropriate to take to erythromycin, with pH6.8 phosphate buffer dissolved and diluted into
0.07,0.14,0.21,0.28,0.35,0.42,0.49 and 0.56mg/ml, respectively the standard solution. Precise amount of each check 1.0ml,
color according to the above method to measure absorbance at 540nm wavelength. A degree in order to absorb the standard solution concentration C (mg / ml) regression, have standard curve equation: A = 1.8452C-0.0042, r = 0.9998.
2.1.4 Solution stability test at room temperature to take the above 0.28mg/ml of the standard solution at room temperature placed, respectively 0,1,2,4,6 and 8h precise amount of color to take 1.0ml measured. The results showed that the absorption of solution in little change in intensity in 4h.
2.1.5 recovery test precision that take dirithromycin 11,14 and 17mg, respectively, 50ml Liangping home, by adding the amount of blank prescription accessories, with pH6.8 phosphate buffer dissolved and diluted to the scale, shake ,
filter. Precise amount of filtrate were added to take 1.0ml, according to the above method of color, were measured at 540nm wavelength absorption. Calculate the measured volume and the recovery rate, the results see Tab.1.
2.1.6 Determination of taking this product, first with hydrochloric acid solution (9 ? 1000) 900ml of solvent, using
basket method, rotation speed 100r/min, after 2h, per tablet enteric-coated films are not allowed to have cracks or softening phenomena; followed by phosphorus salt buffer (pH6.8) 900ml of solvent, 45min, when to take solution 10ml, filtration, taken for the test items as a renewal of the filtrate solution. Another precision that an appropriate reference substance taken to erythromycin, with pH6.8
phosphate buffer dissolved and diluted to 0.28mg/ml solution, as a reference substance solution; precision to take the above-mentioned solution, the volume of 1.0ml, adding 0.10mol / L hydrochloric acid 4.0ml, shake, together accounted for tons of hydrogen imported alcohol test solution 10.0ml, mixing, heating in boiling water for 5min, Yu Bing bath cooling, and then placed at room temperature for 15min. With a blank reagent solution as control, was measured at 540nm wavelength absorption in order to calculate the ratio between the release of percentage.
2.2 sulfuric acid method of color
Color terms used to erythromycin enteric-coated tablets
with the trial under the same conditions as the standard, that is (75 ? 100) sulfuric acid solution 5ml as color reagent, room temperature reaction of 1h, detection wavelength 482nm. Reposted elsewhere in the paper for free download http://
2.2.1 Preparation of standard curve said precision reference standards appropriate to take to erythromycin, with pH6.8 phosphate buffer dissolved and diluted into 32,64,96,128 and 160μg/ml respectively, the standard solution. Precise amount of each check 5.0ml, adding (75 ? 100) sulfuric acid
solution 5ml, shaken, at room temperature for 1h, absorbance measured at 482nm. A degree in order to absorb the standard solution concentration C (μg / ml) regression, have standard
curve equation: A = 0.0064C-0.0766 (r = 0.9993).
2.2.2 Solution stability test at room temperature to take the above 96μg/ml of the standard solution at the room
temperature, respectively 0,1,2,4,6 and the precise amount of 8h take 5.0ml, for color measured. The results showed that the
absorption intensity in solution within 4h little change.
2.2.3 Precision, said recovery test and prescription taken to erythromycin proportion of accessories, plus pH6.8 phosphate buffer dissolution, filtration, respectively, diluted to contain 80,100 to erythromycin and 120μg/ml of the
solution, precise amount of each check 5.0ml, color according to the above method to measure absorbance at 482nm. Calculate the measured volume and the recovery rate, the results of three doses of the recoveries were 99.6%, 100.2% and 99.1%,
the corresponding RSD were 0.8%, 0.6% and 0.5%.
2.2.4 Determination of taking this product, in accordance with the methods described in 2.1.6 under the operation, taking phosphate buffer (pH6.8) for the release of media,
45min after taking solution 10ml, filtration, sophisticated take the amount of filtrate added 2ml by adding phosphate buffer (pH6.8) was diluted to 5ml, as a solution for the test items; the other, said precision reference standards appropriate to take to erythromycin, with phosphate buffer (pH6.8) dissolved and diluted into 100μg/ml solution, as a
reference substance solution; precision to take the above-
mentioned solution, the volume of 5.0ml, according to the
methods described in 2.2.4 under the color determined by
absorbance at 482nm. In order to calculate the ratio between the release of percentage.
2.3 High Performance Liquid Chromatography (HPLC method)
2.3.1 Chromatographic conditions and system suitability test Column: Diamond-C
18 (4.6mm × 250mm, 5μm); mobile phase: acetonitrile:
methanol: phosphate buffer solution (potassium dihydrogen phosphate 1.41g check with dipotassium hydrogen phosphate 6.91g, add water to 1000ml) (44:19: 37); detection wavelength 205nm; flow 2ml/min; column temperature was 40 ?; injection
System suitability test in accordance with USP23 determination to erythromycin enteric-coated tablets under
way. Based on the test results of the provisions of dirithromycin 16R isomers of peaks and 9 (S) erythromycylamine
R12 separation between the peaks of not less than 5.0, to erythromycin 16R and 16S isomers isomers peak separation between the peaks R
23 shall not be less than 2.0.
2.3.2 Accessories and solvent interference in the blank
test results showed that the blank accessories and solvent (pH6.8 phosphate buffer) are in 2min before the peaks, do not interfere with the determination of the sample.
2.3.3 Preparation of standard curve said precision reference standards appropriate to take to erythromycin, plus dissolved in pH6.8 phosphate buffer and were diluted to 0.05,0.10,0.20,0.40, and 0.60mg/ml of the standard solution. Were drawn 10μl, into the liquid chromatograph, record chromatograms, take the amount of peak area to peak area A on
the concentration C (mg / ml) regression, have standard curve equation: A = 553934C 894.69 (r = 0.9999 ).
2.3.4 Solution Stability and precision of the standard solution of 0.20mg/ml to take the above-mentioned conditions,
placed at room temperature, respectively 0,1,2,4 and 6h lessons 10μl, were measured, results showed that, 6h did not
change within the peak area Large, RSD 0.75%. 12:00 a continuous injection six times, recording chromatograms, take the amount of peak area to calculate the relative standard
deviation, RSD 0.66%.
2.3.5 Precision, said recovery test and prescription taken to erythromycin proportion of accessories, plus pH6.8 phosphate buffer dissolution, filtration, respectively, diluted with dirithromycin 0.20,0.25 and 0.30mg/ml solution ,
respectively, absorb 10μl, into the liquid chromatograph,
record chromatograms, the amount of peak area obtained by external standard method to calculate the measured volume and recovery. The results showed that three doses of recoveries
were 100.0%, 99.7% and 99.4%, the corresponding RSD were 0.5%, 0.6% and 0.5%.
2.3.6 Determination of lessons were described under 2.1.6 for the test product solution and reference substance solution 10μl, into the liquid chromatograph, record chromatograms,
the amount of peak area obtained by external standard method to calculate the percentage of the release.
2.4 The test items for the release of Curve Drawing
Erythromycin enteric-coated tablets obtained in six,
according to Chinese Pharmacopoeia 2005 Edition 2 Appendix XD second release rate assay method, using basket method, first used hydrochloric acid solution (9 ? 1000) 900ml of solvent,
speed 100r/min, After 2h, per tablet enteric-coated films are
not allowed to have cracks or softening phenomena; followed by pH6.8 phosphate buffer solution (900ml) for the release of media, speed of 100r/min. 5,10,20,30,45, and 60min, respectively, samples were taken precise amount of filtrate added amount, respectively, according to the above three
methods of treatment solution, and measured data to calculate per unit in the buffer medium in the release, each point in time are measured as the mean of six emission release point in time, drawing the release curves, and compare the different
determination of differences between the release curves obtained (Fig.1). Results show that the determination of the above-mentioned three kinds of dissolution to the measured curves of the release of erythromycin enteric-coated tablets
are basically the same.
(1) to compare the above-mentioned three kinds of
erythromycin enteric-coated tablets to release rate
determination method, the mouth alcohol accounted for tons of hydrogen chromogenic law set forth in the United States
Pharmacopoeia method, the operation tedious, and the color reagent is no domestic production, to be imported; sulfuric acid chromogenic method for our trial drugs specified in the standard method of advantages for the reagents readily available, easy to operate quick; HPLC method for the
reference to the U.S. Pharmacopoeia to erythromycin enteric-
coated tablet Assay Methods, the advantages for accurate, high sensitivity, but we need a longer time, higher cost.
(2) The three methods all have high accuracy, the
measured difference between the release curves of the smaller. But taken together, sulfuric acid color method low cost, easy to operate, in order to erythromycin enteric-coated tablets
release rate determination of the best way.
(3) using the above-mentioned three methods measured
restraint 45min emissions of erythromycin enteric-coated
tablets each contributed around 100% of the labeled amount, indicating the preparation of the release of good performance.
(4) USP23 prescribed method, the mouth alcohol accounted for tons of hydrogen is used in solid, while domestic only its 10% methanol solution sales, therefore, the mouth alcohol accounted for tons of hydrogen used in chromogenic France accounted for 10% of the population of methanol alcohol tons
of hydrogen solution, methodology studies show that this change will not affect the measurement accuracy of the results.
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