Study of the formation of micro and nano-droplets containing immiscible solutions

Formulation and in vitro evaluation of meloxicam as a self-microemulsifying drug delivery system

Background: The nonsteroidal anti-inflammatory medication meloxicam (MLX) belongs to the oxicam family and is used to reduce inflammation and pain. The aim of this study was to improve MLX's dispersibility and stability by producing it as a liquid self-microemulsifying drug delivery system since it is practically insoluble in water. Methods: Five different formulations were made by adjusting the amounts of propylene glycol, Transcutol P, Tween 80, and oleic acid oil and establishing a pseudo-ternary diagram in ratios of 1:1, 1:2, 1:3, 1:4, and 3:4, respectively. All of the prepared formulations were tested for a variety of properties, including thermodynamic stability, polydispersity index, particle size distributions, dilution resistance, drug contents, dispersibility, in vitro solubility of the drug, and emulsification time. Results: F5 was chosen as the optimal MLX liquid self-microemulsion due to its higher drug content (99.8%), greater in vitro release (100% at 40 min), smaller droplet size (63 nm), lower polydispersity index (PDI) value (0.3), and higher stability (a zeta potential of -81 mV). Conclusions: According to the data provided here, the self-microemulsifying drug delivery system is the most practical method for improving the dispersibility and stability of MLX.

Chemotaxis-based smart drug delivery of epirubicin using a 3D printed microfluidic chip

Recent developments on self-propelled microdroplets, moving controllably in response to an external stimulus like chemical, electrical, or magnetic field, have opened a new horizon for smart drug delivery investigations. On the other hand, the new achievements in 3D printing technology has provided a promising option for the fabrication of microfluidic devices, which is an unrivalled platform for in-vitro drug delivery studies. By synergizing the features of chemotaxis, 3D printing, and microfluidic techniques a new approach was introduced to deliver the drug to targeted sites with a well-controlled method and a reasonable speed. A self-propelled ionic liquid ([P_6,6,6,14][Cl]) microdroplet, as the drug carrier, was utilised for the targeted delivery of epirubicin anticancer drug within an integrated drug delivery microfluidic system. The asymmetric diffusion of [P_6,6,6,14]⁺ ion from the microdroplet into an aqueous solution with chloride gradient concentration (created under an external electrical field) caused the microdroplet to move. The spatial and temporal position of the moving microdroplet could be controlled by changing the magnitude and polarity of the external electrical field. A piece of hollow-fiber, fixed next to the anode, was filled with phosphate buffer (as the receptor) and used to remove the drug from the carrier. The receptor solution was then taken and injected into a HPLC system for quantification of the released drug. After one-at-a-time optimization of the channel geometry and electrolyte concentration, the experimental variables affecting the drug loading including contact time, pH, and volume of carrier were optimized via a central composite design (CCD) approach.

Properties of polidocanol foam in view of its use in sclerotherapy

Foam sclerotherapy is a widely used method to treat varicose veins disease. It is easy to use and apply, affordable, and has high efficiency that depends on foam stability upon injection. Since sclerotherapy is usually applied in a medical doctor's office, one of the most employed methods to generate foam is based on the Tessari technique which uses pumping cycles of liquid and air in-and-out of a double syringe system. Finally, the produced foam exits through a small orifice (∼2mm) at the output of a three-way valve. The present work shows results regarding the factors that may influence foam stability (liquid to air ratio, type of connector, syringe diameter, number of pumping cycles, etc.) of a commonly used sclerosing agent (polidocanol). Furthermore, an effort is made to evaluate the effect of adding different substances on the stability of polidocanol foams (0.5% w/w) by altering the surface tension or/and the bulk and interfacial rheological properties of the fluids. It is shown that adding small concentrations of nonionic surfactants can increase foam stability with just a very small variation of the mean bubbles size.

Photo-chemopropulsion--light-stimulated movement of microdroplets

The controlled movement of a chemical container by the light-activated expulsion of a chemical fuel, named here "photo-chemopropulsion", is an exciting new development in the array of mechanisms employed for controlling the movement of microvehicles, herein represented by lipid-based microdroplets. This "chemopropulsion" effect can be switched on and off, and is fully reversible.