Nonionic surfactant structure on the drug release, formulation and physical properties of ethylcellulose microspheres

Abstract

Evaluate the effects of nonionic surfactants Brij 58 and Tween 40 with different structures but similar hydrophilic lipophilic balances (HLBs) on theophylline (TH)-loaded ethylcellulose (EC) microspheres. Microspheres were formulated using ratios of the surfactants with matching HLB values but different chemical-structures at temperatures (22/35 °C) by hydrophobic solvent-emulsion evaporation. Particle size, GMD, drug loading, encapsulation efficiency and dissolution were evaluated. Drug release was determined using the zero- and first-order, Higuchi and Hixson-Crowell models. EC microspheres prepared with surfactant Brij 58 showed discrete, free-flowing spherical particles, solid interiors and increased particle smoothness as temperature increased; those prepared with Tween 40 appeared porous with coarser surface morphology as temperature increased; both were CHLB (Combined HLB) dependent. Dissolution obeyed the Higuchi model drug release for both microspheres prepared with Tween 40 and Brij 58 except for those prepared with Brij 58 at 35 °C, which presented as zero order. The results were ascribed to the different chemical structure of Brij 58 versus Tween 40 and preparation temperature. Surfactant chemical structure is an unreported processing parameter shown here to be important in microsphere formulation. Brij 58 possesses properties unique to its chemical structure that influence pharmaceutical and molecular biopharmaceutical research.

A Critical Scrutiny on Liposomal Nanoparticles Drug Carriers as Modelled by Topotecan Encapsulation and Release in Treating Cancer

“…Endogenous drug carriers like exosomes and cell membranes are being studied [ 7 , 8 ]. Exogenous drug carriers such as nanoparticles [ 9 ], dendrimers [ 10 ], starch microspheres, ethyl cellulose microspheres, albumin microspheres, gelatin microspheres [ 11 , 12 ], and liposomes [ 13 ].…”

Hydroalcoholic Extract of Myrcia bella Loaded into a Microemulsion System: A Study of Antifungal and Mutagenic Potential

“…As a surfactant, a mixture of Brij 58 and soy phosphatidylcholine was used. Brij 58 is a nonionic surfactant with hydrophilic-hydrophobic equilibrium [15]. Nonionic surfactants offer a considerable advantage in that they do not need a co-reagent for the formation of microemulsions [16].…”

“…Vegetable oils such as corn, cotton, orange, triglycerides, and esters of fatty acids (isopropyl myristate, ethyl oleate, etc.) are often used as oily components to develop “biocompatible microemulsions” 14 , 15 .…”

F7 and topotecan co-loaded thermosensitive liposome as a nano-drug delivery system for tumor hyperthermia

“…Based on the tumor enhanced permeability and retention effect, liposomes can accumulate at the tumor site to improve drug efficacy (Tiet & Berlin, 2017 ; Golombek et al., 2018 ; Li et al., 2019 ). However, the release of drugs from liposomes is relatively slow; therefore, various response triggers have been investigated to improve drug release, including pH (Yuba et al., 2018 ), temperature (Lokerse et al., 2016 ), ultrasound (Wang et al., 2018 ), photodynamic conversion (Lee et al., 2018 ), and microwaves (Jin et al., 2016 ), which allow drugs to be rapidly and specifically released at the tumor site. In 1985, hyperthermia was certified by the FDA as the fifth most widely used cancer treatment method after surgery, radiation therapy, chemotherapy, and biotherapy (Shetake et al., 2016 ; Mitxelena-Iribarren et al., 2020 ).…”