Microparticles based on chitosan/pectin polyelectrolyte complexes for nasal delivery of tacrine hydrochloride

Theophylline-Loaded Pectin/Chitosan Hydrochloride Submicron Particles Prepared by Spray Drying with a Continuous Feeding Ultrasonic Atomizer

Pectin/chitosan hydrochloride (CHC) particles containing theophylline were prepared by a spray-drying apparatus coupled with a continuous feeding ultrasonic atomizer and a heating column. The formation of the submicron particles was investigated at various compositions of pectin solutions added with a chitosan hydrochloride or calcium chloride solution as a crosslinking agent. Scanning electron microscopic (SEM) images showed the pectin/chitosan hydrochloride particles had spherical and smooth surfaces. Depending on the feeding concentrations, the produced particles had diameters in the range of 300 to 800 nm with a narrow size distribution. Furthermore, the theophylline (TH)-loaded pectin/CHC particles were also prepared by the same apparatus. The TH release from the submicron particles in phosphate-buffered saline at 37 °C was monitored in real-time by a UV-Visible spectrophotometer. The Ritger-Peppas model could well describe the TH release profiles. All the diffusional exponents (n) of the release systems were greater than 0.7; thus, the transport mechanism was not a simple Fickian diffusion. Particularly, the n value was 1.14 for the TH-loaded particles at a pectin/CHC weight ratio of 5/2, which was very close to the zero-order drug delivery (n = 1). Therefore, the constant drug-release rate could be achieved by using the spray-dried pectin/CHC particles as the drug carrier.

Spray dried powders for nasal delivery: Process and formulation considerations

Powders for nasal delivery have been recognized as advantageous dosage forms over liquids due to increased stability and residence time on nasal mucosa, with improved bioavailability. They can be manufactured by spray-drying, allowing the optimization of the particle properties that are critical to guarantee nasal deposition, as size and shape. It is also a scalable and flexible method already explored extensively in the pharmaceutical industry. However, it is important to understand how process parameters, particle physical properties and formulation considerations affect the product performance. Hence, this review aims to provide an overview of nasal powder formulation and processing through spray drying, with an emphasis on the variables that impact on performance. To this purpose, we describe the physical, biological and pharmacological phenomena prior to drug absorption as well as the most relevant powder properties. Formulation considerations including qualitative and quantitative composition are then reviewed, as well as manufacturing considerations including spray drying relevant parameters.

Preparation and Characterization of Mucoadhesive Loratadine Nanoliposomes for Intranasal Administration

Objectives

The present study aimed to formulate and characterize mucoadhesive liposomes for intranasal delivery of loratadine. In particular, the formulation was aimed to improve the drug bioavailability and efficacy.

Materials and Methods

Liposomes were prepared by thin-film hydration method, with soybean phosphatidylcholine and cholesterol as main components. Liposomes were coated with chitosan solution at a concentration of 0.05% and 0.1%, w/v. The formulations were assessed for particle size, polydispersity index (PDI), encapsulation efficiency (EE), thermodynamic behavior, in vitro drug release, mucoadhesiveness, and stability.

Results

Particle size analysis showed that the vesicles of uncoated and coated liposomes with 0.05% and 0.1% chitosan were characterized by size of 193±3.3 nm, 345±4.6, and 438±7.3 nm, respectively. Size distribution for developed formulations was in the acceptable range (PDI <0.7). EE was recorded to be approximately 80%. Chitosan-coated liposomes demonstrated slower release rate as compared to uncoated liposomes. Drug release kinetics profile for all the formulations followed a zero-order model. Chitosan coating improved mucoadhesiveness by more than 3-fold as compared to uncoated liposomes. However, no significant differences were recorded between mucin adsorption behavior of 0.05% and 0.1% chitosan-coated liposomes (p>0.05). For stability studies, liposomes were stored at 4°C for 3 months, and changes in particle diameter, PDI, and EE % were recorded. No significant alternations were reported in particles size, PDI, and drug leakage of coated liposomes.

Conclusion

Liposomes coated with 0.05% chitosan were chosen as the optimum formulation, which demonstrated a significant potential for overcoming the nasal drug delivery limits for short residence time and mucociliary clearance.

Benzoic acid complexes with Eudragit E100®: New alternative antimicrobial preservatives

Given that the use of some preservatives in cosmetics has been restricted, novel alternative preservatives are needed. The aim of this study was to characterize the physicochemical and antimicrobial properties of two polyelectrolyte complexes (EuB₁₀₀ and EuB₇₅Cl₂₅), which were developed through hot melt extrusion (HME) using benzoic acid (BA) and Eudragit E100. Based on phase diagrams and an experimental statistical design, the solubility of the acid in the polymer and the HME conditions were established. Intermolecular interactions were evaluated through Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and X-ray powder diffraction (XRPD). Release behavior was determined for the systems. Antibacterial activity and ζ-potential were determined on Escherichia coli. FTIR revealed acid-base interaction, and XPS showed that the percentages of protonated nitrogen N1s were 13.5% for EuB₁₀₀ and 20.3% for EuB₇₅Cl₂₅. The BA released showed a non-Fickian behavior, and a satisfactory antibacterial activity against E. coli was demonstrated at pH 6.9. The complexes modified ζ-potential, destabilizing the membrane functionality of E. coli. These complexes are potential antimicrobial preservatives with a greater spectrum of action, with bactericidal activity against E. coli in a wider pH range than uncomplexed BA, even at pH 6.9.

In situ thermo-co-electroresponsive mucogel for controlled release of bioactive agent

The purpose of this work was to develop an in situ thermosensitive electro-responsive mucoadhesive gel loaded with bioactive agent (nanocomposite) meant for nose to brain delivery in a controllable manner when electric stimulation is applied. Nanocomposite was developed using a combinatorial blending of chitosan, hydroxypropylmethylcellulose, pluronic F127 and polyaniline which was then loaded with BCNU-Nano-co-Plex (the bioactive agent). The nanocomposite was a liquid at room temperature but formed an in situ mucogel at a temperature of 27.5 ± 0.5 °C. Furthermore, the nanocomposite possessed a redox element which makes it responsive to electrical stimulation (ES). The stimuli responsiveness enabled the formulation to release the bioactive agent when electrical potential was applied and demonstrated a desired 10.28% release of nanoparticles per application cycle. The results further revealed pore formation within the formulation which accommodated the loaded nanoparticles. The release profile also demonstrated a pulsatile release of the bioactive material when subjected to ES. This formulation may therefore be useful as a nose to brain drug delivery system that can be modulated to deliver bioactive agents to the brain via electro-actuation in an "on-off" drug release kinetics by means of an external ES for a controlled nose-to-brain delivery.

Biological Activity and Pharmacological Application of Pectic Polysaccharides: A Review

Pectin is a polymer with a core of alternating α-1,4-linked d-galacturonic acid and α-1,2-l-rhamnose units, as well as a variety of neutral sugars such as arabinose, galactose, and lesser amounts of other sugars. Currently, native pectins have been compared to modified ones due to the development of natural medicines and health products. In this review, the results of a study of the bioactivity of pectic polysaccharides, including its various pharmacological applications, such as its immunoregulatory, anti-inflammatory, hypoglycemic, antibacterial, antioxidant and antitumor activities, have been summarized. The potential of pectins to contribute to the enhancement of drug delivery systems has been observed.

Opportunity and challenges of nasal powders: Drug formulation and delivery

In the field of nasal drug delivery, among the preparations defined by the European Pharmacopoeia, nasal powders facilitate the formulation of poorly water-soluble active compounds. They often display a simple composition in excipients (if any), allow for the administration of larger drug doses and enhance drug diffusion and absorption across the mucosa, improving bioavailability compared to nasal liquids. Despite the positive features, however, nasal products in this form still struggle to enter the market: the few available on the market are Onzetra Xsail® (sumatriptan) for migraine relief and, for the treatment of rhinitis, Rhinocort® Turbuhaler® (budesonide), Teijin Rhinocort® (beclomethasone dipropionate) and Erizas® (dexamethasone cipecilate). Hence, this review tries to understand why nasal powder formulations are still less common than liquid ones by analyzing whether this depends on the lack of (i) real evidence of superior therapeutic benefit of powders, (ii) therapeutic and/or commercial interest, (iii) efficient manufacturing methods or (iv) availability of suitable and affordable delivery devices. To this purpose, the reader's attention will be guided through nasal powder formulation strategies and manufacturing techniques, eventually giving up-to-date evidences of therapeutic efficacy in vivo. Advancements in the technology of insufflation devices will also be provided as nasal drug products are typical drug-device combinations.

Structured Biodegradable Polymeric Microparticles for Drug Delivery Produced Using Flow Focusing Glass Microfluidic Devices

Biodegradable poly(DL-lactic acid) (PLA) and poly(lactic-co-glycolic acid) (PLGA) microparticles with tunable size, shape, internal structure and surface morphology were produced by counter-current flow focusing in axisymmetric (3D) glass capillary devices. The dispersed phase was composed of 0.5-2 wt % polymer solution in a volatile organic solvent (ethyl acetate or dichloromethane) and the continuous phase was 5 wt % aqueous poly(vinyl alcohol) solution. The droplets with a coefficient of variation in dripping regime below 2.5% were evaporated to form polymeric particles with uniform sizes ranging between 4 and 30 μm. The particle microstructure and surface roughness were modified by adding nanofiller (montmorillonite nanoclay) or porogen (2-methylpentane) in the dispersed phase to form less porous polymer matrix or porous particles with golf-ball-like dimpled surface, respectively. The presence of 2-4 wt % nanoclay in the host polymer significantly reduced the release rate of paracetamol and prevented the early burst release, as a result of reduced polymer porosity and tortuous path for the diffusing drug molecules. Numerical modeling results using the volume of fluid-continuum surface force model agreed well with experimental behavior and revealed trapping of nanoclay particles in the dispersed phase upstream of the orifice at low dispersed phase flow rates and for 4 wt % nanoclay content, due to vortex formation. Janus PLA/PCL (polycaprolactone) particles were produced by solvent evaporation-induced phase separation within organic phase droplets containing 3% (v/v) PLA/PCL (30/70 or 70/30) mixture in dichloromethane. A strong preferential adsorption of Rhodamine 6G dye onto PLA was utilized to identify PLA portions of the Janus particles by confocal laser scanning microscopy (CLSM). Uniform hemispherical PCL particles were produced by dissolution of PLA domes with acetone.