COMUNICAÇÃO TÉCNICA Nº 173776 Determination of fragrance

COMUNICAÇÃO TÉCNICA
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Nº 173776
Determination of fragrance encapsulation efficiency using proton
NMR spectroscopy
Martha González-Pérez,
Adriano Marim de Oliveira
Renato R. Gavioli
Natália Neto Pereira Cerize
Romário Souza Gois
Poster apresentado no NUCLEAL MAGNETIC RESONANCE
USERS MEETING, 15., 2015, Angra do Reis. Poster...
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DETERMINATION OF FRAGRANCE ENCAPSULATION EFFICIENCY USING PROTON NMR
SPECTROSCOPY
Martha González-Pérez*1, Adriano M. de Oliveira2, Renato R. Gavioli 2; Natália N. P. Cerize 2, Romário S. Gois2
1Instituto
de Pesquisas Tecnológicas do Estado de São Paulo S.A – IPT. Centro de Química e Manufaturados. Predio 48. Av. Profº Almeida Prado, 532 – Cidade
Universitária. CEP: 05508-901 - São Paulo – SP, Brasil.
2Instituto de Pesquisas Tecnológicas do Estado de São Paulo S.A – IPT. Núcleo de Bionanomanufatura. Predio 50. Av. Profº Almeida Prado, 532 – Cidade Universitária.
CEP: 05508-901 - São Paulo – SP, Brasil.
Introduction
The encapsulation efficiency, which is a measure of the percentage of the total compound entrapped within the nanoparticles, is an important parameter of
characterization of multifunctional nanoparticles synthesized aiming several uses of technological interest, such as special coating agents for multifunctional, high
comfort, protective textiles with sun blocking properties as well as controlled release of fragrance.
Most of the reported experimental methods in the literature to determine encapsulation efficiency require removal of the free (unencapsulated) particles using column
chromatography, centrifugation, or dialysis before measurement. The physical separation has some disadvantages and there is not always possible to be sure it was
completed.
Zhang et al. (2004) proposed a rapid and simple approach to determine the encapsulation efficiency that avoids the need for physical separation of entrapped and nonentrapped nanoparticles using 1H-NMR. Zhang approach is tested in the present study for determining the encapsulation efficiency of fragrance in multifunctional
polymer nanoparticles.
Materials and Methods
The multifunctional nanoparticles properties were prepared from silicon dioxide (SiO2) and titanium dioxide (TiO2) aqueous colloidal suspensions, with mean particle
diameters of 20 nm and 25 nm. Two different monomers were used: methyl methacrylate (MMA) and styrene (Sty), together with two different functional comonomers,
sodium styrene sulphonate (StySO3Na) and hydroxyethyl methacrylate (HEMA) which enhance the system’s stability. The fragrance “SoftNeo II” (SNII, Symrise) was used
as an active ingredient together with the sunscreen agents, for the nanocapsules. The fragrance could be detected by sensorial analysis even after synthesis, showing no
degradation or chemical modification of this fragrance compounds.
1H NMR spectra were acquired in a VARIAN NMR spectrometer, model 400 MR, operating at 400 MHz frequency for hydrogen.
In 5 mm NMR tubes, were prepared three solutions:
1 ) solution containing ~8 mg of fragrance in 600 µL of deuterated chloroform with tetramethylsilane (TMS) as reference standard for chemical shift ,
2) solution containing ~8 mg of nanoparticles in 600 µL of deuterated water with 1mg of 3-(trimethylsilyl)propionic acid sodium salt (TSP) as reference standard for
chemical shift ,
3) solution containing ~8 mg of encapsulated fragrance in 600 µL of deuterated water with 1 mg of TSP as reference standard for chemical shift .
The following parameters were used for acquisition: temperature 25°C, spectral width 6410 Hz, acquisition time 2.55 s, relaxation delay 2 s.
Results and Discussions
The 1H NMR spectra are shown in Figures 1, 2 and 3. In the Figure 1, it is shown the spectra of fragrance SoAncoII where can be observed many different signals. The
spectrum of nanoparticles NTX 43 shows no signal, but D2O signal (Figure 2) . The third spectrum is the spectrum of encapsulated fragrance NTX47 and comparing to
the Figure 1 it is possible to observed that most of signals do not appeared.
The fragrance could be detected by sensorial analysis after synthesis, showing no degradation or chemical modification of the fragrance compounds. Thus, it was
obtained a good encapsulation efficiency. The next step will be quantified the percentage of the fragrance entrapped within the nanoparticles.
Figure 1 - 1H NMR spectrum of fragrance SoAncoII .
Figure 2 - 1H NMR spectrum of nanoparticles NTX 43.
Figure 3 - 1H NMR spectrum of encapsulated fragrance NTX47.
Conclusions
The results show a good encapsulation efficiency; therefore confirming, that NMR method is in fact very simple and has some advantages over the other commonly
used methods, like short analysis time, use no solvent and avoids the need for physical separation of entrapped and non-entrapped nanoparticles.
References:
Zhang X.M.; Patel A.B.; Graaf R.A.; Behar, K.L. Determination of liposomal encapsulation efficiency using proton NMR spectroscopy . Chemistry and Physics of Lipids. 2004,
127:113-120.
Acknowledgment: