Next Article in Journal
Co-Delivery of M2e Virus-Like Particles with Influenza Split Vaccine to the Skin Using Microneedles Enhances the Efficacy of Cross Protection
Next Article in Special Issue
An In Vitro Study of the Influence of Curcuma longa Extracts on the Microbiota Modulation Process, In Patients with Hypertension
Previous Article in Journal
Phospholipid-Based Prodrugs for Colon-Targeted Drug Delivery: Experimental Study and In-Silico Simulations
Previous Article in Special Issue
Development of a New Ex Vivo Lipolysis-Absorption Model for Nanoemulsions
Open AccessArticle

Gellan Gum/Laponite Beads for the Modified Release of Drugs: Experimental and Modeling Study of Gastrointestinal Release

1
Dipartimento di Ingegneria Chimica, Materiali e Ambiente, Sapienza Universitá di Roma, Via Eudossiana 18, 00184 Rome, Italy
2
Dipartimento di Chimica e Tecnologie del Farmaco, Sapienza Universitá di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy
3
Department of Pharmacy, University of Oslo, 0316 Oslo, Norway
*
Author to whom correspondence should be addressed.
Pharmaceutics 2019, 11(4), 187; https://doi.org/10.3390/pharmaceutics11040187
Received: 19 March 2019 / Revised: 3 April 2019 / Accepted: 11 April 2019 / Published: 17 April 2019
In this study, gellan gum (GG), a natural polysaccharide, was used to fabricate spherical porous beads suitable as sustained drug delivery systems for oral administration. GG was cross-linked with calcium ions to prepare polymeric beads. Rheological studies and preliminary experiments of beads preparation allowed to identify the GG and the CaCl2 concentrations suitable for obtaining stable and spherical particles. GG beads were formed, through ionotropic gelation technique, with and without the presence of the synthetic clay laponite. The resultant beads were analyzed for dimensions (before and after freeze-drying), morphological aspects and ability to swell in different media miming biological fluids, namely SGF (Simulated Gastric Fluid, HCl 0.1 M) and SIF (Simulated Intestinal Fluid, phosphate buffer, 0.044 M, pH 7.4). The swelling degree was lower in SGF than in SIF and further reduced in the presence of laponite. The GG and GG-layered silicate composite beads were loaded with two model drugs having different molecular weight, namely theophylline and cyanocobalamin (vitamin B12) and subjected to in-vitro release studies in SGF and SIF. The presence of laponite in the bead formulation increased the drug entrapment efficiency and slowed-down the release kinetics of both drugs in the gastric environment. A moving-boundary swelling model with “diffuse” glassy-rubbery interface was proposed in order to describe the swelling behavior of porous freeze-dried beads. Consistently with the swelling model adopted, two moving-boundary drug release models were developed to interpret release data from highly porous beads of different drugs: drug molecules, e.g., theophylline, that exhibit a typical Fickian behavior of release curves and drugs, such as vitamin B12, whose release curves are affected by the physical/chemical interaction of the drug with the polymer/clay complex. Theoretical results support the experimental observations, thus confirming that laponite may be an effective additive for fabricating sustained drug delivery systems. View Full-Text
Keywords: beads; gellan gum; ionotropic gelation; laponite; modeling study; swelling; gastrointestinal drug release; polymer/clay composite beads; gellan gum; ionotropic gelation; laponite; modeling study; swelling; gastrointestinal drug release; polymer/clay composite
Show Figures

Graphical abstract

MDPI and ACS Style

Adrover, A.; Paolicelli, P.; Petralito, S.; Di Muzio, L.; Trilli, J.; Cesa, S.; Tho, I.; Casadei, M.A. Gellan Gum/Laponite Beads for the Modified Release of Drugs: Experimental and Modeling Study of Gastrointestinal Release. Pharmaceutics 2019, 11, 187.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop