Swellable matrices for controlled drug delivery: gel-layer behaviour, mechanisms and optimal performance

Colombo, Paolo; Bettini, Ruggero; Santi, Patrizia; Peppas, Nikolaos A.

doi:10.1016/s1461-5347(00)00269-8

Cited by 345 publications

(199 citation statements)

References 27 publications

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“…As HME and FDM printing both were performed at temperatures above the melting point of the crystalline PEO and PEG, higher melt viscosity of the matrix polymer would be more effective in limiting the diffusion of PEG and PEO molecules to form large crystalline domains during recrystallization on cooling (post-FDM printing). However despite the fact that PEO is a well-known controlled release matrix excipient which hydrates and swells once it is in contact with aqueous media [39][40][41][42], the limited amount of swelling observed in CME and CMS discs during dissolution, indicated that the dissolution of PEO/PEG in the dispersions is the more dominant process in these blends. The intimate mixing between PEG/PEO and Soluplus and Eudragit E PO may contribute to this observed behavior.…”

Section: Linking Phase Behavior With In Vitro Disintegration and Dissmentioning

confidence: 99%

An investigation into the use of polymer blends to improve the printability of and regulate drug release from pharmaceutical solid dispersions prepared via fused deposition modeling (FDM) 3D printing

Alhijjaj

Belton

2016

European Journal of Pharmaceutics and Biopharmaceutics

236

134

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FDM 3D printing has been recently attracted increasing research efforts towards the production of personalized solid oral formulations. However, commercially available FDM printers are extremely limited with regards to the materials that can be processed to few types of thermoplastic polymers, which often may not be pharmaceutically approved materials nor ideal for optimizing dosage form performance of poor soluble compounds. This study explored the use of polymer blends as a formulation strategy to overcome this processability issue and to provide adjustable drug release rates from the printed dispersions. Solid dispersions of felodipine, the model drug, were successfully fabricated using FDM 3D printing with polymer blends of PEG, PEO and Tween 80 with either Eudragit E PO or Soluplus. As PVA is one of most widely used polymers in FDM 3D printing, a PVA based solid dispersion was used as a benchmark to compare the polymer blend systems to in terms processability. The polymer blends exhibited excellent printability and were suitable for processing using a commercially available FDM 3D printer. With 10% drug loading, all characterization data indicated that the model drug was molecularly dispersed in the matrices.During in vitro dissolution testing, it was clear that the disintegration behavior of the formulations significantly influenced the rates of drug release. Eudragit EPO based blend dispersions showed bulk disintegration; whereas the Soluplus based blends showed the 'peeling' style disintegration of strip-by-strip. The results indicated that interplay of the miscibility between excipients in the blends, the solubility of the materials in the dissolution media and the degree of fusion between the printed strips during FDM process can be used to manipulate the drug release rate of the dispersions. This brings new insight into the design principles of controlled release formulations using FDM 3D printing.

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Section: Linking Phase Behavior With In Vitro Disintegration and Dissmentioning

confidence: 99%

An investigation into the use of polymer blends to improve the printability of and regulate drug release from pharmaceutical solid dispersions prepared via fused deposition modeling (FDM) 3D printing

Alhijjaj

Belton

2016

European Journal of Pharmaceutics and Biopharmaceutics

236

134

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“…6 The gel becomes a viscous layer acting as a protective barrier to both the influx of water and the efflux of the drug in solution. 7,8 As reported by Ford et al, 9 as the proportion of the polymer in the formulation increases, the gel formed is more likely to diminish the diffusion of the drug and delay the erosion of the matrix. Narasimhan and Peppas 10 showed that the dissolution can be either disentanglement or diffusion controlled depending on the molecular weight and thickness of the diffusion boundary layer.…”

Section: Introductionmentioning

confidence: 84%

Design and evaluation of matrix-based controlled release tablets of diclofenac sodium and chondroitin sulphate

Avachat

Kotwal²

2007

AAPS PharmSciTech

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The purpose of the present study was to develop and characterize an oral controlled release drug delivery system for concomitant administration of diclofenac sodium (DS) and chondroitin sulfate (CS). A hydrophilic matrix-based tablet using different concentrations of hydroxypropylmethylcellulose (HPMC) was developed using wet granulation technique to contain 100 mg of DS and 400 mg of CS. Formulations prepared were evaluated for the release of DS and CS over a period of 9 hours in pH 6.8 phosphate buffer using United States Pharmacopeia (USP) type II dissolution apparatus. Along with usual physical properties, the dynamics of water uptake and erosion degree of tablet were also investigated. The in vitro drug release study revealed that HPMC K100CR at a concentration of 40% of the dosage form weight was able to control the simultaneous release of both DS and CS for 9 hours. The release of DS matched with the marketed CR tablet of DS with similarity factor (f 2 ) above 50. Water uptake and erosion study of tablets indicated that swelling followed by erosion could be the mechanism of drug release. The in vitro release data of CS and DS followed KorsmeyerPeppas and zero-order kinetics, respectively. In conclusion, the in vitro release profile and the mathematical models indicate that release of CS and DS can be effectively controlled from a single tablet using HPMC matrix system.

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“…After the initial phase, the release was dependent on the composition of the matrix core, in particular, the grade and concentration of HPMC. The ability of the HPMC particles to hydrate and form a gel layer around a core is well-known and is essential to sustaining and controlling the release of a drug from the matrix (34). Throughout the dissolution test, a continuous gel layer formed in the HPMC matrix core was responsible for guiding the release of the drug.…”

Section: Discussionmentioning

confidence: 99%

Development of Modified-Release Tablets of Zolpidem Tartrate by Biphasic Quick/Slow Delivery System

Mahapatra

Sameeraja

Murthy³

2014

AAPS PharmSciTech

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Abstract. Zolpidem tartrate is a non-benzodiazepine analogue of imidazopyridine of sedative and hypnotic category. It has a short half-life with usual dosage regimen being 5 mg, two times a day, or 10 mg, once daily. The duration of action is considered too short in certain circumstances. Thus, it is desirable to lengthen the duration of action. The formulation design was implemented by preparing extended-release tablets of zolpidem tartrate using the biphasic delivery system technology, where sodium starch glycolate acts as a superdisintegrant in immediate-release part and hydroxypropyl methyl cellulose as a release retarding agent in extended-release core. Tablets were prepared by direct compression. Both the core and the coat contained the drug. The pre-compression blends were evaluated for angle of repose, bulk density, and compressibility index. The tablets were evaluated for thickness, hardness, weight variation test, friability, and in vitro release studies. No interaction was observed between zolpidem tartrate and excipients from the Fourier transform infrared spectroscopy and differential scanning calorimetry analysis. The results of all the formulations prepared were compared with reference product Stilnoct®. Optimized formulations showed release patterns that match the United States Pharmacopeia (USP) guidelines for zolpidem tartrate extended-release tablets. The mechanism of drug release was studied using different mathematical models, and the optimized formulation has shown Fickian diffusion. Accelerated stability studies were performed on the optimized formulation.

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Swellable matrices for controlled drug delivery: gel-layer behaviour, mechanisms and optimal performance

Cited by 345 publications

References 27 publications

An investigation into the use of polymer blends to improve the printability of and regulate drug release from pharmaceutical solid dispersions prepared via fused deposition modeling (FDM) 3D printing

An investigation into the use of polymer blends to improve the printability of and regulate drug release from pharmaceutical solid dispersions prepared via fused deposition modeling (FDM) 3D printing

Design and evaluation of matrix-based controlled release tablets of diclofenac sodium and chondroitin sulphate

Development of Modified-Release Tablets of Zolpidem Tartrate by Biphasic Quick/Slow Delivery System

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