Application of Spray Drying Particle Engineering to a High-Functionality/Low-Solubility Milk Thistle Extract: Powders Production and Characterization

Abstract

Many natural compounds having antioxidant and anti-inflammatory activity are a potential target for new therapies against chronic inflammatory syndromes. The oral administration of functional herbal supplements may become a prevention strategy or therapy adjuvant for susceptible patients. A case study is our milk thistle (Silybum marianum) extract rich in silymarin complex. A water-soluble microencapsulated powder system was developed by a spray drying technique to improve the poor silymarin bioactivity after oral administration. Sodium carboxymethylcellulose (NaCMC) was employed as coating/swelling polymer matrix and sodium lauryl sulfate (SLS) as the surfactant (1:1:0.05 w/w/w). A H2O/EtOH/acetone (50/15/35 v/v/v) solvent system was used as liquid feed. The microsystems were capable of improving the in vitro dissolution and permeation rates, suggesting an enhancement of bioactivity after oral administration. The microsystems protect the antioxidant activity of silymarin after harsh storage conditions period and do not affect the anti-inflammatory properties of the raw extract (efficient already at lower concentrations of 0.312 mg/mL) to reduce dendritic cells (DCs) inflammatory cytokine secretion after lipopolysaccharide administration. This approach allows managing particle size, surface properties and release of bioactive agents improving the bioactivity of a herbal supplement and is also possibly applicable to many other similar natural products.

Design and Development of Spray-Dried Microsystems to Improve Technological and Functional Properties of Bioactive Compounds from Hazelnut Shells

“…The results of the MTT test (Table 3) showed that the inhibitory effect of Batch-15 (AEC% 3.9%, w/w) remained unchanged for SK-Mel-28 (IC 50 10.550 mg/mL containing 0.411 mg/mL of HSE) or resulted in improved for A375 and HeLa (IC 50 4.550 and 8.070 mg/mL, containing 0.177 and 0.315 mg/mL of HSE, respectively), proving as the spray drying process did not affect HSE efficacy. On the contrary, the produced amorphous microsystems were able to improve the wettability of HSE and the release of HSE active components in water cellular environmental [13]. Moreover, the occurrence of proline in the multi-polymeric Batch-15 matrix will affect the cytotoxic properties of the HSE raw extract.…”

“…More than 45 pilot experiments (blank and loaded powders, Table 1) were carried out to find the optimum of liquid feed in terms of polymer concentrations and weight polymer ratios with respect to the process yields, loading ability, and resultant powders technological characteristics. As an example, only three batches (3,9,12) of blank powders and two batches of loaded (13,15) ones have been selected, discussed in the text, and reported in the Table 1 as demonstrative samples of the taken experimental steps. Additional information was included in the Supplementary Materials.…”

“…The very low standard deviation obtained confirms the homogeneity of the formulation also in terms of loading and distribution of the extract in the matrix. The increase of solubility in aqueous media is of great importance because this characteristic can enhance the functionality of the spray-dried powders [9,13].…”

“…These critical features could limit the real use of natural polyphenol derivatives as therapeutic/nutraceutical agent, negatively affecting the absorption process, the bioavailability after the intake, the handling, and the storage during the industrial scale use [11]. Moreover, the potential phytochemicals degradation process over time may reduce the active ingredient content and, consequently, the functional value of the plant extract [10,12,13]. In the present research, a particle engineering approach, involving the production of microparticles by spray drying technique, is proposed to overcome the stability and bioavailability problems, converting the raw HSE in a powder, suitable for the final administration in various dosage forms (mainly oral or topical ones) as an active ingredient [14,15].…”

“…The spray drying is an atomization technique, widely employed in the food and pharmaceutical field, to transform a starting liquid feed into a microparticulate powder [16]. This microencapsulation technique has been successfully applied to heat-sensitive materials such as plant extracts to obtain a processed material showing enhanced technological properties (solid-state, particle dimensions, morphology, and water dissolution rate), stability of active components within the polymeric matrix, and an efficient release to target site of application/action, with respect to the plant raw extract [13,[17][18][19][20]. The design and development of plant-based powders are a technological challenge involving the study of several critical aspects (solvent system, liquid feed preparation method, polymeric matrix components) and the optimization of the experimental plan also considering both the chemical-functional characteristics of the plant extract and the intended use of the final product.…”