Development of W1/O/W2 emulsion with gallic acid in the internal aqueous phase.

The aim of this work is to develop a W1/O/W2 multiple emulsion with gallic acid in the internal aqueous phase (W1). A quantification method for gallic acid using HPLC-UV was developed and validated. In the first step, a simple W1/O emulsion was prepared with distilled water, polyglycerol polyricinoleate, sodium chloride, gallic acid and pH 5.0 sodium acetate buffer system. The second step consisted of adding the simple emulsion to the external aqueous phase (W2) composed of distilled water, polysorbate 80 and xanthan gum. The multiple emulsion showed pseudoplastic behavior. After 28 days of analysis the multiple emulsion presented a stability index of 75% without pH variation, 89.61% of gallic acid concentration, 59.62% of antioxidant activity in the phosphomolybdenum complex assay and 80.58% of DPPH scavenging activity. It is concluded that the W1/O/W2 emulsion developed was stable for 28 days and maintained more than 50% of gallic acid antioxidant capacity.

Effect of Cilostazol-Loaded PCL/PEG Nanocapsules on Abdominal Aortic Tunics and Lipid Profile of Wistar Rats

Abstract Cilostazol (CLZ) is a phosphodiesterase III inhibitor with antiplatelet and vasodilator properties. It has been recently verified that CLZ plays a significant role in the arteries by inhibiting the proliferation and growth of muscle cells, increasing the release of nitric oxide by the endothelium and promoting angiogenesis. Considering these promising effects, the use of nanocapsules may be an interesting strategy to optimize its pharmacokinetics and pharmacodynamics at the vascular level for preventing atherosclerosis. The aim of this study was to evaluate the effect of cilostazol-loaded nanocapsules in the abdominal aortic tunics and on the lipid profile of Wistar rats in order to investigate its potential role in the prevention of atherosclerosis. Thirty-two animals were divided into four groups of eight animals, with 30-day treatment. Group 1 received nanoencapsulated CLZ; Group 2, control nanocapsules with no drug; Group 3, propylene glycol and water; and Group 4, a solution of CLZ in propylene glycol and water. After 30 days, there was no statistically significant difference between the groups regarding the cellularity and thickness of the arterial tunics of the abdominal aorta. However, the group that received nanoencapsulated CLZ (Group 1) had an improvement in HDL-c and triglyceride values compared to unloaded nanocapsules (Group 2).

Long-lasting anti-platelet activity of cilostazol from poly(ε-caprolactone)-poly(ethylene glycol) blend nanocapsules.

Cilostazol (CLZ) acts as a vasodilator and antiplatelet agent and is the main drug for the treatment of intermittent claudication (IC) related to peripheral arterial disease (PAD). The usual oral dose is 100 mg twice a day, which represents a disadvantage in treatment compliance. CLZ presents several side effects, such as headache, runny nose, and dizziness. This paper aimed to obtain novel polymeric nanocapsules prepared from poly(ε-caprolactone)-poly(ethylene glycol) (PCL-PEG) blend containing CLZ. Nanocapsules showed pH values between 6.1 and 6.3, average size lower than 137 nm, low polydispersity index (<0.22) and negative zeta potential. These nanoformulations demonstrated spherical shape with smooth surface. Results achieved by X-ray diffraction (XRD) and differential scanning calorimetry (DSC) indicated drug amorphization compared to pure CLZ. Fourier-transformed infrared spectroscopy (FTIR) showed no chemical bonds between drug and polymers. Formulations presented suitable stability for physical parameters. The in vitro drug release demonstrated prolonged release with no burst effect. Drug release was controlled by both mechanisms of polymer relaxation/degradation and Fickian diffusion. Moreover, chosen CLZ-loaded nanocapsules provided an in vivo prolonged antiplatelet effect for CLZ statistically similar to aspirin. These formulations can be further used as a feasible oral drug delivery carrier for controlled release of CLZ in order to treat PAD and IC events.

Spray-dried solid dispersions containing ferulic acid: comparative analysis of three carriers, in vitro dissolution, antioxidant potential and in vivo anti-platelet effect.

This article aimed to improve the relative solubility and dissolution rate of ferulic acid (FA) by the use of spray-dried solid dispersions (SDs) in order to ensure its in vitro antioxidant potential and to enhance its in vivo anti-platelet effect. These SDs were prepared by spray-drying at 10 and 20% of drug concentration using polyvinylpyrrolidone K30 (PVP-K30), polyethylene glycol 6000 (PEG 6000) and poloxamer-188 (PLX-188) as carriers. SDs and physical mixtures (PM) were characterized by SEM, XRPD, FTIR spectroscopy and TGA analysis. Spray-dried SDs containing FA were successfully obtained. Relative solubility of FA was improved with increasing carrier concentration. PVP-K30 and PEG 6000 formulations showed suitable drug content values close to 100%, whereas PLX-188 presented mean values between 70 and 90%. Agglomerates were observed depending on the carrier used. XRPD patterns and thermograms indicated that spray-drying led to drug amorphization and provided appropriate thermal stability, respectively. FTIR spectra demonstrated no remarkable interaction between carrier and drug for PEG 6000 and PLX-188 SDs. PVP-K30 formulations had changes in FTIR spectra, which denoted intermolecular O-H•••O = C bonds. Spray-dried SDs played an important role in enhancing dissolution rate of FA when compared to pure drug. The free radical-scavenging assay confirmed that the antioxidant activity of PEG 6000 10% SDs was kept. This formulation also provided a statistically increased in vivo anti-platelet effect compared to pure drug. In summary, these formulations enhanced relative solubility and dissolution rate of FA and chosen formulation demonstrated suitable in vitro antioxidant activity and improved in vivo anti-platelet effect.

Spray-dried Eudragit® L100 microparticles containing ferulic acid: Formulation, in vitro cytoprotection and in vivo anti-platelet effect.

This paper aimed to obtain new spray-dried microparticles containing ferulic acid (FA) prepared by using a methacrylic polymer (Eudragit® L100). Microparticles were intended for oral use in order to provide a controlled release, and improved in vitro and in vivo biological effects. FA-loaded Eudragit® L100 microparticles were obtained by spray-drying. Physicochemical properties, in vitro cell-based effects, and in vivo platelet aggregation were investigated. FA-loaded Eudragit® L100 microparticles were successfully prepared by spray-drying. Formulations showed suitable encapsulation efficiency, i.e. close to 100%. Microparticles were of spherical and almost-spherical shape with a smooth surface and a mean diameter between 2 and 3µm. Fourier-transformed infrared spectra demonstrated no chemical bond between FA and polymer. X-ray diffraction and differential scanning calorimetry analyses indicated that microencapsulation led to drug amorphization. FA-loaded microparticles showed a slower dissolution rate than pure drug. The chosen formulation demonstrated higher in vitro cytoprotection, anti-inflammatory and immunomodulatory potential and also improved in vivo anti-platelet effect. These results support an experimental basis for the use of FA spray-dried microparticles as a feasible oral drug delivery carrier for the controlled release of FA and improved cytoprotective and anti-platelet effects.