morphological analysis and size distribution evaluation of

MORPHOLOGICAL ANALYSIS AND SIZE DISTRIBUTION EVALUATION
OF EUDRAGIT® S100 COATING MAGNETITE, AMOXICILLIN AND
CLARITHROMYCIN MICROPARTICLES
PONTES, T.R.F 1; SILVA-FREITAS, E.L 1; SILVA, K.L 1; ARAÚJO-NETO, R.P 1; CARVALHO, J.F 1;
EGITO, E.S.T 1; CARRIÇO, A.S 2
1
Departamento de Farmácia, Universidade Federal do Rio Grande do Norte, Rua Gal Gustavo Cordeiro
de Farias s/n, Petrópolis, CEP: 59010-180, Natal-RN, Brazil.
2
Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte,
Campus universitário, CEP: 59078-970, Natal-RN, Brazil.
Keywords: Magnetic drug delivery; Morphological; Size distribution.
[email protected]
1. Introduction
3. Results
Helicobacter pylori is a gram-negative
bacterium that causes gastritis and ulcers. The
most commonly used regimen for the
eradication of this bacterium is a triple therapy
(omeprazole, amoxicillin and clarithromycin). A
patient who uses this scheme will have to take
high doses of drugs. One technique able to
overcome this disadvantage is the magnetic
drug targeting, which is an efficient way of
delivering a drug to localized disease sites
employing an external magnetic field. The aim
of this work was to develop a magnetic system
containing
magnetite,
amoxicillin
and
clarithromycin coated with Eudragit® S100 to
treatment of Helicobacter pylori and also
characterize the system by morphological and
size distribution analysis.
Although the particle size distribution of MP
and PP demonstrated a bimodal distribution,
their average size is below 15 µm (Table 1).
This indicates and predicts a good release
profile. Also, the particle size shows a decrease
in the span index of PP by a factor of 1.82,
indicating a smaller polydispersity for PP than
MP. The increment in the average size of the
particles as well as the changes seen in their
surfaces, observed in the scanning electron
microscopy, revealed that the MP and drugs
were successfully coated by Eudragit® S100.
2. Methods
The first step to obtain the magnetic system was
the synthesis of the magnetite particles (MP) by
the coprecipitation method. An acidic solution
of FeCl3 and FeSO4 (2:1 in mol, respectively)
was added to a medium containing NaOH 1 M
(resulting in magnetite). The second step
consisted in the production of Eudragit® S100
polymeric particles (PP) with amoxicillin and
clarithromycin by the spray-drying technique.
The Eudragit was dispersed in phosphate buffer
pH 7.4, clarithromycin was dissolved in
methanol and amoxicillin in water. The
dispersions were mixed and magnetite was
added, later the suspension was dried by
atomization. The powder was analyzed by
scanning electron microscopy (to evaluate the
morphology) and optical microscope with a
stage micrometer scale (according to the
Ferret´s diameter principle) to determine the
average size, D10, D50, D90 and span index.
Table 1. Mean diameter size (± SD), D10, D50,
D90 and span index of magnetite and
polymeric particles
Magnetite
Polymeric
particles
SD
particles
SD
Mean
diameter
(µm)
6.854
0.208 14.126 0.115
D10
(µm)
4.483
0.105 11.427 0.262
D50
(µm)
6.777
0.366 13.943 0.056
D90
(µm)
9.295
0.211 16.856 0.081
Span
index a
0.710
0.390
a
Span index = (D90-D10)/D50
4. Conclusion
The magnetic polymer system has suitable size
distribution for magnetic drug delivery by oral
route. In addition, the morphology study
showed that the magnetite particles and drugs
were coated by Eudragit® S100.
Acknowledgments
CNPq, CAPES.