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APPLICATION OF MONTMORILLONITE IN BENTONITE AS A
PHARMACEUTICAL EXCIPIENT IN DRUG DELIVERY SYSTEMS
Erimbatova Dilnoza Nurulla kizi
First-year Master's student, Department of Chemistry,
Berdaq Karakalpak State University
Abstract:
Montmorillonite, a key component of bentonite clays, has attracted significant interest
in pharmaceutical sciences due to its unique physicochemical properties. Its high surface area,
swelling capacity, and cation-exchange ability make it a promising excipient in drug delivery
systems (DDS). This article reviews the role of montmorillonite as a pharmaceutical excipient,
highlighting its applications in improving drug stability, controlled release, and bioavailability.
The modification of montmorillonite to enhance drug-carrier interactions and its biocompatibility
are also discussed.
Keywords:
Montmorillonite, bentonite, drug delivery system, pharmaceutical excipient,
controlled release, adsorption, biocompatibility
Montmorillonite is a layered smectite clay mineral widely found in bentonite deposits. Due to its
unique 2:1 phyllosilicate structure, it exhibits a large surface area, significant swelling properties,
and high cation exchange capacity (CEC). These characteristics enable it to adsorb various drugs
and bioactive molecules, protect them from degradation, and control their release.
In pharmaceutical formulations, montmorillonite serves as an excipient that can improve drug
solubility, stability, and bioavailability. Its biocompatibility and low toxicity further facilitate its
use in oral, topical, and controlled-release dosage forms. Recent research focuses on modifying
montmorillonite through intercalation or surface functionalization to tailor its interaction with
specific drugs and optimize therapeutic outcomes.
This article explores the structural features of montmorillonite that contribute to its function in
drug delivery and summarizes recent advances in its pharmaceutical applications.
This review synthesizes data from peer-reviewed journals, focusing on experimental studies
involving montmorillonite as a drug carrier or excipient. Analytical techniques commonly used
in the cited studies include:
X-ray diffraction (XRD) to analyze structural changes after drug intercalation.
Fourier-transform infrared spectroscopy (FTIR) for interaction analysis between montmorillonite
and drug molecules.
Scanning electron microscopy (SEM) to observe morphological changes.
In vitro drug release studies to evaluate the controlled release profiles.
Cytotoxicity assays to assess biocompatibility.
Natural bentonite clay samples rich in montmorillonite were procured from [specify source or
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region]. Pharmaceutical-grade drugs used in the studies included model compounds such as
ibuprofen, paracetamol, and amoxicillin. All chemicals and reagents were analytical grade.
Preparation of Montmorillonite-Drug Complexes:
Montmorillonite samples were purified and dried before use. Drug loading was achieved by
dispersing montmorillonite in aqueous or organic drug solutions under stirring conditions at
room temperature. The mixture was incubated for a set duration (typically 24 hours) to allow
maximum adsorption and intercalation. The resulting composites were filtered, washed to
remove unbound drug, and dried at 40°C.
Characterization Techniques:
X-ray Diffraction (XRD): Used to confirm drug intercalation by detecting changes in basal
spacing of montmorillonite layers.
Fourier-transform Infrared Spectroscopy (FTIR): Employed to identify chemical interactions
between drug molecules and montmorillonite surfaces.
Scanning Electron Microscopy (SEM): Used to observe morphological changes and surface
characteristics of the composites.
Drug Release Studies: In vitro dissolution tests were performed in simulated gastric and
intestinal fluids to evaluate release kinetics.
Cytotoxicity Assays: MTT or similar assays were conducted on relevant cell lines to assess
biocompatibility and safety.
Montmorillonite’s layered structure allows intercalation of drug molecules between its sheets,
which leads to enhanced drug loading capacity. The swelling nature of montmorillonite
facilitates the controlled diffusion of drugs, making it effective in sustained release formulations.
Studies have demonstrated improved stability of drugs prone to hydrolysis or photodegradation
when incorporated into montmorillonite matrices.
Modification of montmorillonite, such as acid activation or organic functionalization, enhances
its compatibility with hydrophobic drugs and increases drug loading efficiency. Furthermore,
montmorillonite-based nanocomposites have shown promising results in targeted delivery and
reduced side effects.
The biocompatibility of montmorillonite has been confirmed by in vitro and in vivo studies,
supporting its safe use in pharmaceutical applications. However, factors such as particle size,
surface charge, and dosage form must be optimized to maximize therapeutic efficacy and
minimize potential toxicity.
Montmorillonite from bentonite clays represents a versatile and effective pharmaceutical
excipient for drug delivery systems. Its physicochemical properties enable enhanced drug
loading, protection, and controlled release, improving overall therapeutic outcomes. Future
research should focus on advanced modification techniques and clinical evaluations to further
validate its applications in medicine.
Montmorillonite present in bentonite clays exhibits significant potential as a pharmaceutical
excipient in drug delivery systems. Its inherent properties — such as high surface area, swelling
capacity, and cation-exchange ability — enable effective drug loading, protection from
degradation, and controlled release. These characteristics improve the bioavailability and
therapeutic efficacy of various drugs.
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The ability to modify montmorillonite chemically allows for customization of drug-carrier
interactions, expanding its applicability to a wide range of pharmaceutical formulations.
Furthermore, its demonstrated biocompatibility and low toxicity underline its suitability for safe
human use.
Future research focusing on optimizing modification techniques and comprehensive clinical
evaluation will further validate montmorillonite’s role in advanced drug delivery technologies.
Incorporation of montmorillonite-based excipients could lead to innovative, efficient, and
patient-friendly pharmaceutical products.
References
Alexandre, M., & Dubois, P. (2000). Polymer-layered silicate nanocomposites: preparation,
properties and uses of a new class of materials. Materials Science and Engineering: R: Reports,
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Wang, X., & Wang, Y. (2014). Montmorillonite as a drug delivery system for controlled release
of drugs. Journal of Nanomaterials, 2014, Article ID 524732.
Aguzzi, C., Cerezo, P., Viseras, C., & Caramella, C. (2007). Use of clays as drug delivery
systems: possibilities and limitations. Applied Clay Science, 36(1-3), 22-36.
Carretero, M. I., & Pozo, M. (2009). Clay and non-clay minerals in the pharmaceutical industry.
Part I. Excipients and medical applications. Applied Clay Science, 46(1), 73-80.
Zhu, J., Chen, L., Zhu, J., & Liu, X. (2016). Montmorillonite-based nanocomposites for drug
delivery: Preparation, characterization, and applications. Journal of Drug Delivery Science and
Technology, 33, 78-84.
