Pluronic-cationic surfactant mixed micelles: Solubilization and release of the drug hydrochlorothiazide

Moderately hydrophobic poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPOPEO) block copolymers [Pluronics (R) with 20 > % PEO < SO] form micelles in water with a hydrodynamic diameter of about 20 nm. The aqueous mixed systems of Pluronics P103, P104 and P105 [Pluronics1) with molecular weight of PPO =3250, and % of PEO 30,40 and 50 respectively] with cationic surfactants of the type alkyltrimethylammonium bromide (C TAB, n= 10, 12, 14 and 16) were studied in water and salt solution. It is apparent that the presence of trace amounts of cationic surfactant induces a charge on nonionic Pluronics micelles and leads to a decrease in their size. The efficiency of surfactants to decrease micellar size depends on the alkyl chain length of the surfactants. A representative system, P103-C14TAB was chosen to investigate and the feasibility of using Pluronie-surfactants systems compared with pure Pluronic micelle as an in vitro release vehicle for hydrochlorothiazide (HCT); a hydrophobic diuretic drug with poor aqueous solubility. Pluronie-surfactant systems were found to be more efficient for HCT loading; their loading capacity can be tuned by changing the surfactant concentration and pH. Drug release profiles were established for P103 and P103-C14TAB mixed systems, The rate of controlled release of HCT from micelles was explained by employing different kinetic models to examine the in vitro release profile..(C) 2013 Elsevier B.V. All rights reserved.