Affordable Access

Publisher Website

The adsorption of cellulose ethers in aqueous suspensions of pyrantel pamoate: effects on zeta potential and stability

Authors
Journal
European Journal of Pharmaceutics and Biopharmaceutics
0939-6411
Publisher
Elsevier
Publication Date
Volume
45
Issue
2
Identifiers
DOI: 10.1016/s0939-6411(97)00103-3
Keywords
  • Aqueous Suspensions
  • Physical Stability
  • Hydroxypropylmethylcellulose
  • Sodium Carboxymethylcellulose
  • Pyrantel Pamoate
  • Interfacial Adsorption
  • Zeta Potential
Disciplines
  • Chemistry

Abstract

Abstract This work examined the physico-chemical phenomena induced in aqueous suspensions of pyrantel pamoate by two varieties of hydroxypropylmethylcellulose (HPMC) and sodium carboxymethylcellulose (NaCMC) of different molecular weights, and the effects of these phenomena on the physical stability of the suspension. The mechanism of the interfacial adsorption of the polymer was investigated by constructing adsorption isotherms: for the two HPMC varieties, the isotherms were of type L and were fitted with the Langmuir model; of the NaCMCs, only the variety with higher molecular weight was adsorbed, its adsorption isotherm being of type S (sigmoidal). The resulting monolayer films were characterized viscosimetrically, determining their thickness and the number of polymer molecules adsorbed per unit area. The nonionic polymers formed thinner, more continuous monolayers than the NaCMC. Only the nonionic polymers significantly altered the zeta potential of the systems. In the range of conditions studied, all the polymers stabilized the initially flocculated systems, decreasing sedimentation volume and increasing the time necessary to redisperse them (the redispersabilily value). This stabilization occurred either by the steric mechanism (HPMCs and the high-molecular-weight NaCMC) or by depletion mechanisms (low-molecular-weight NaCMC). Owing to the complexity of these mechanisms, sedimentation volume was not found to be a useful index of the consistency of the sediments obtained from the suspensions.

There are no comments yet on this publication. Be the first to share your thoughts.

Statistics

Seen <100 times
0 Comments

More articles like this

The adsorption of cellulose ethers in aqueous susp...

on European Journal of Pharmaceut... March 1998

Adsorption of polysorbate 80 on pyrantel pamoate:...

on International Journal of Pharm... Jan 01, 1998

Adsorption of pyrantel pamoate on mercury from aqu...

on Journal of Colloid and Interfa... Jan 01, 2010

Effect of sodium oleate adsorption on the colloida...

on Diamond and Related Materials Jan 01, 2005
More articles like this..