Preparation and evaluation of novel microemulsion-based hydrogels for dermal delivery of benzocaine

Abstract

The purpose of the current research was to prepare and evaluate the potential use of microemulsion-based hydrogel (MBH) formulations for dermal delivery of benzocaine (BZN). The pseudoternary-phase diagrams were constructed for various microemulsions composed of isopropyl myristate (IPM) as oil phase, Span 20, Tween 20, Tween 80, cremophor EL and cremophor RH40 as surfactants, ethanol as cosurfactant and distilled water as aqueous phase. Finally, concentration of BZN in microemulsions was 2% (w/w). The physicochemical properties, such as conductivity, viscosity, pH, droplet size, polydispersity index and zeta potential of microemulsions, were measured. Carbopol 940 was used to convert BZN-loaded microemulsions into gel form without affecting their structure. Furthermore, excised rat abdominal skin was used to compare permeation and penetration properties of BZN loaded M3 and M3BHs with BZN solution. According to ex vivo study results, BZN-loaded M3BH1 showed highest flux values and high release rate values, and furthermore, this gel formulation had low surfactant content. Finally, in order to learn the localization of formulations within the dermal penetration, formulations and BZN solution were labeled with red oil O and subjected to fluorescence observation. In conclusion, BZN-loaded MBHs could be offered as a promising strategy for dermal drug delivery.

Preparation, optimization and in vivo anti-inflammatory evaluation of hydroquinone loaded microemulsion formulations for melasma treatment

“…Microemulsions are homogeneous, transparent; thermodynamically stable dispersions optically isotropic liquid system of oil and water, stabilized by a suitable surfactant and cosurfactant [10]. They have several pharmaceutical advantages, such as ease of preparation, transparency and potentials for solubilizing variety of drugs [11]. Microemulsions plays important role to deliver drugs to patients in several ways but one of the most important ways of delivering drug to patients by using microemulsion is topical application [12].…”

Design, Development, and Optimization of Dexibuprofen Microemulsion Based Transdermal Reservoir Patches for Controlled Drug Delivery

“…pH was found to be between 4.66 ± 0.04 and 5.46 ± 0.02. An ideal pH for skin preparations must be between 5 and 6, as the acidic pH leads to skin irritation while the basic pH promotes microbial growth on skin [33]. The pH of formulations F4, F5, and F6 was found within this range.…”

“…As the surfactant concentration increases, the droplet size decreases. Oil and cosurfactant concentrations also affect the particle size [33]. The microstructure may also be altered due to the interaction between loaded drug and microemulsion components.…”

Functionalized Textile Based Therapy for the Treatment of Atopic Dermatitis

“…This hydrogel therapy was shown to be effective in improving the quality life of AD patients [149]. Recently, a microemulsion based hydrogel loaded with benzocaine was constructed for dermal purposes [150]. Nayak and colleagues reported carboxymethyl cellulose/gelatin copolymer hydrogel containing lidocaine as a transdermal delivery [151].…”

“…Moreover, the droplet size of emulsions may range from around tens of nanometers to about hundreds of nanometers. Emulgel can be classified into macroemulsion gel (100-400 nm), microemulsion gel (10-100 nm), and nanoemulsion gel (about 10 nm) [150,173]. The nanoscale emulsion facilitates penetration across the skin, which makes emulgel more appropriate for transdermal use.…”