Salt Effect on the Cloud Point Phenomenon of Amphiphilic Drug-Hydroxypropylmethyl Cellulose System

Abstract

Effect of two amphiphilic drugs (tricyclic antidepressant, nortriptyline hydrochloride (NORT), and nonsteroidal anti-inflammatory drug, sodium salt of ibuprofen (IBF)) on the cloud point of biopolymer hydroxypropylmethyl cellulose (HPMC) was studied. Effect of NaCl was also seen on the CP of HPMC-drug system. CP of HPMC increases uniformly on increasing the (drug). Both drugs, though one being anionic (IBF) and other cationic (NORT), affect the CP in almost the same manner but with different extent implying the role of hydrophobicity in the interaction between drug and polymer. Salt affects the CP of the drug in a dramatic way as low concentration of salt was only able to increase the value of the CP, though not affecting the pattern. However, in presence of high concentration of salts, minimum was observed on CP versus (drug) plots. Various thermodynamic parameters were evaluated and discussed on the basis of the observed results.

Synthesis and Evaluation of Finasteride-Loaded HPMC-Based Nanogels for Transdermal Delivery: A Versatile Nanoscopic Platform

“…HPMC is an important amphiphilic carrier substance that plays an important part in the penetration of moieties through skin. Amphiphilic substance utilize intercellular channels for infiltration through biological membranes [ 74 ]. Carbopol-based composites are reported to have accelerated rate of solute diffusion across biological barriers [ 75 ].…”

Chain-Length Shortening of Methyl Ethyl Hydroxyethyl Cellulose: An Evaluation of the Material Properties and Effect on Foaming Ability

“…Clouding is a macroscopic phenomenon, caused by the formation of aggregates, and is believed to be caused by a decrease in the dipolar character of the C-O bond where the molecule becomes less and less polar with increasing temperature [8,9].…”

“…Sodium sulphate, Na 2 SO 4 , which was used to promote the mixing of the components and to reduce the cloud point [9,10] of the cellulose derivative was dispersed in one litre of deionized water and heated to 93 °C during stirring with a propeller mixer. Then 100 g of the MEHEC derivative was added.…”