poster bioencapsulation
DESCRIPTION
Encapsulation polyphenols Green tea,TRANSCRIPT
W. P. Oliveira, V.C. Pessan, V.A. Secolin and C.R.F. Souza*
Faculty of Pharmaceutical Sciences of Ribeirão Preto/USP, Ribeirão Preto, SP, Brazil
Figure 2. Lipid compositions developed: (a) with cholesterol and (b) with stearic acid.
( A ) ( B )
Figure 5. Optical microscopy of compositions
containing cholesterol (50 and 500 x).
Figure 6. Optical microscopy of compositions
containing stearic acid (50 and 500 x).
Figure 4. Visual aspect of spray dried lipid dispersions
obtained with cholesterol (A) and stearic acid (B) with
membrane stabilizer.
( A ) ( B )
INTRODUCTION
OBJECTIVES
Recently, advances in pharmaceutical research is focused on new delivery
systems utilizing new devices to achieve modification of delivery time, targeting, as
well as improve the in vivo solubility and hence bioavailability of poorly soluble
drugs. Liposomes consist of one or more lipid and/or phospholipid bilayers can
contain other molecules such as proteins or carbohydrates in their structure and
are generally classified by their structural properties or by the method of
preparation of the vesicles (MOZAFARI et al, 2008). Have as main advantage the
ability to encapsulate water soluble active (inside the cavity) and soluble (in the
bilayer) (Figure 1a). However, liposomal systems have the disadvantage of low
stability due to its high water content limiting their long-term storage (shelf life).
Payne et al. (1986) proposed the production of stable liposomes, by obtaining pro-
liposomes, which are dried product with good flow properties, the active
compounds and phospholipids which, upon addition of water disperse to form a
multi-lamellar liposome (Figure 1b).
Figure 1. (a) encapsulation of water-soluble and fat-soluble bioactive in liposomal systems, and (b)
formation of multi-lamellar liposome of proliposome by addition of water and stirring controlled.
The aim of this work was the development and characterization of
proliposomes loaded with lyophilized extract of P. guajava through spray drying. It
was evaluated the effects of the stabilizer of the lipid membrane (CH: cholesterol or
AS: stearic acid), and the drying and stabilizer agents (GL: glycerol, SB: sorbitol,
TR: trehalose and LC: lactose).
MATERIAL AND METHODS
Development of lipid compositions loaded with P. guajava bioactive
compounds: hydrogenated soy phosphatidylcholine 90 % (Phospholipon® 90H,
Lipoid GMBH), and cholesterol 94 % (Sigma-Aldrich) or stearic acid (Via pharma,
Brazil) as lipid membrane stabilizer were used. Four carbohydrates, namely,
glycerol (BASF), sorbitol (Sigma-Aldrich), lactose M-200 (Natural Pharma Ltda,
Brazil) and D(+) trehalose (Sigma-Aldrich) were evaluated as drying and stabilizer
agent of the lipid system. The lipid dispersions were prepared according Secolin et
al. (2014), using 4 % of soy lecithin, 2 % of lyophilized extract, 12 mL of n-butyl
alcohol as lipids solubilizer (Table 1).
Table 1: Membrane stabilizer and drying adjuvant added to lipid composition.
Production of proliposomes by spray drying: The stable lecithin based
dispersions were dried in a Lab-Plant SD-05 spray dryer (Lab-Plant Ltd, UK)
(Figure 3). Feed rate of 4 g/min, inlet temperature 100 °C, drying gas flow rate 60
m3/h, pressure and spray gas flow: 5 kgf/cm2 and 17 lpm. The proliposomes were
characterized through determination of the moisture content (Xp), water activity
(aW), total polyphenols (PT), bulk and tapped density (b and t) and flow properties
(Carr´s index - IC) and Hausner ratio - HR) (Table 2).
Figure 3. Spray dryer used.
RESULTS AND DISCUSSION
CONCLUSIONS
REFERENCES
MOZAFARI, M.R. et al., Int. J. Food Properties, 11, 833–844, 2008.
PAYNE, N.I.; et al., J. Pharm. Sci., 75(4):325–329, 1986.
SECOLIN, V.A.; OLIVEIRA W.P.; SOUZA, C.R.F. Anais XXXVI Congresso Brasileiro de Sistemas Particulados, 1-10, 2014.
The formulation LPG4 (CH and LC), showed a better drying performance,
generating a product with Xp values (2.5%) and aW (0.21), and high concentration
of PT (14.2%).
The spray dried proliposomes were classified as cohesive and restrict flow
powders.
Figures 5 and 6 show the obtained optical microscopy, obtained globules sizes
of 5 and 10 microns for formulations containing for cholesterol and stearic acid
respectively; all remained homogeneous and stable (Figure 2). The rheological
analysis showed that all the formulations analyzed exhibit non-Newtonian behavior
of pseudoplastic type.
Table2: Physicochemical characterization of the spray dried proliposomes.
swelling water dried lipid membrane
agitation
Lipid layer
fat-soluble active
in the bilayer
water-soluble active
inside the bilayer