The influence of protonation ratio on properties of carboxymethyl starch excipient at various substitution degrees: Structural insights and drug release kinetics

International Journal of Pharmaceutics
E Assaad, M A Mateescu


Carboxymethyl starch (CMS) with pH sensitivity modulated by the protonation ratio (PR 0-100%) and the degree of substitution (DS 0.07-0.20) was synthesized in aqueous medium. The properties of CMS excipient and the mechanism of acetaminophen release from monolithic tablets in simulated gastric fluid (SGF, pH 1.2) and in simulated intestinal fluid (SIF, pH 6.8) were investigated. Compared to sodium CMS, the protonated CMS provided a longer release time which increases with the increase of PR. Over storage time, the highly protonated CMS showed a decrease in solubility and a progressive structural alteration due to hydrogen bonded carboxyl groups. Simultaneously, an acceleration of release rate of formulated drug was observed. The CMS(DS 0.11) with PR up to 50% showed relatively low sensitivity to dissolution medium pH and sustained release pattern almost independent of tablet preincubation in SGF and of drug loading (20% and 40%). The CMS(DS 0.20) was more sensitive to pH and showed an accelerated release rate in SIF. For the CMS formulations, a diffusion mechanism was suggested in SGF, whereas in SIF the release was mostly controlled by swelling and erosion.


Sep 24, 1999·European Journal of Pharmaceutical Sciences : Official Journal of the European Federation for Pharmaceutical Sciences·P ColomboN A Peppas
Jun 14, 2002·International Journal of Pharmaceutics·S EdgeJ N Staniforth
Nov 16, 2004·Colloids and Surfaces. B, Biointerfaces·Tomofumi HaradaMasayuki Tokita
Jun 1, 2007·International Journal of Pharmaceutics·Carmen CalinescuMircea-Alexandru Mateescu
Jan 24, 2009·Biomaterials·Lan WeiTao Chen

❮ Previous
Next ❯


Apr 9, 2013·European Journal of Pharmaceutics and Biopharmaceutics : Official Journal of Arbeitsgemeinschaft Für Pharmazeutische Verfahrenstechnik E.V·Maria Mihaela FriciuMircea Alexandru Mateescu
Jan 28, 2014·Colloids and Surfaces. B, Biointerfaces·Jinlong YangXinjie Zhang
Dec 25, 2015·Saudi Pharmaceutical Journal : SPJ : the Official Publication of the Saudi Pharmaceutical Society·Sonia Lefnaoui, Nadji Moulai-Mostefa
Apr 8, 2017·Drug Delivery and Translational Research·Tien Canh Le, Mircea Alexandru Mateescu
Oct 1, 2016·AAPS PharmSciTech·Pompilia Ispas-SzaboMircea Alexandru Mateescu
Mar 18, 2015·Biotechnology and Applied Biochemistry·Lindsay BlemurMircea Alexandru Mateescu
Jun 5, 2019·Pharmaceutics·Nassim BenyerbahMircea Alexandru Mateescu
Oct 5, 2011·Journal of Biomaterials Science. Polymer Edition·Elias AssaadMircea Alexandru Mateescu
Feb 18, 2021·Carbohydrate Polymers·Malihe Pooresmaeil, Hassan Namazi
Jul 17, 2020·International Journal of Biological Macromolecules·Leire UrbinaAloña Retegi
Sep 29, 2020·Journal of Pharmaceutical Sciences·Kouadio Victorien KonanMircea Alexandru Mateescu

❮ Previous
Next ❯

Related Concepts

Trending Feeds


Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.


Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.


Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.

Related Papers

European Journal of Pharmaceutics and Biopharmaceutics : Official Journal of Arbeitsgemeinschaft Für Pharmazeutische Verfahrenstechnik E.V
Carmen Calinescu, M A Mateescu
European Journal of Pharmaceutics and Biopharmaceutics : Official Journal of Arbeitsgemeinschaft Für Pharmazeutische Verfahrenstechnik E.V
Carmen CalinescuM A Mateescu
International Journal of Pharmaceutics
Carmen CalinescuMircea-Alexandru Mateescu
© 2021 Meta ULC. All rights reserved