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Joiris, E; P, Di Martino; Berneron, C; Am, Guyot-Hermann; Jc, Guyot

doi:10.1023/a:1011954800246

Cited by 259 publications

(102 citation statements)

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“…Acetaminophen has been reported with two types of intermolecular hydrogen bonding (Chart 1) which was important to control the stability of different polymorphs. According to the X-ray crystallographic data, 1,2,7,8) the form I acetaminophen exhibited a stronger hydrogen bonding than form II. The distance of NH··O assigned to the type A hydrogen bonding and OH··O assigned to the type B hydrogen bonding in acetaminophen crystal is 2.91 and 2.65Å for form I and 2.97 and 2.72Å for form II, respectively.…”

Section: Resultsmentioning

confidence: 99%

“…On the other hand, the orthorhombic acetaminophen not only has a sliding plane for good compression but also shows a faster dissolution rate than the monoclinic form. [6][7][8] Therefore, many studies have focused on how to prepare the orthorhombic form of acetaminophen. [8][9][10] An unstable third modification of acetaminophen (form III) has been found after different crystallization methods and the cooling rates, but the ambiguous explanations due to various differential scanning calorimetry (DSC) curves obtained have caused argument.…”

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confidence: 99%

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Transformation of Metastable Forms of Acetaminophen Studied by Thermal Fourier Transform Infrared (FT-IR) Microspectroscopy.

2002

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Acetaminophen is still worldwide used for analgesic and antipyretic therapy by millions of tablets and other dosage forms. Two polymorphs of acetaminophen have been published: form I is a monoclinic crystal and form II is an orthorhombic crystal. Form I (the usual form) is more stable at room temperature than form II.1-4) Form I has poor binding and densification properties, 5,6) and is not suitable for direct compression into tablet. The preparation for monoclinic acetaminophen tablets therefore needs a series of time-and material consuming processes and excipients, and the size of the tablets cannot but be enlarged. On the other hand, the orthorhombic acetaminophen not only has a sliding plane for good compression but also shows a faster dissolution rate than the monoclinic form. [6][7][8] Therefore, many studies have focused on how to prepare the orthorhombic form of acetaminophen. [8][9][10] An unstable third modification of acetaminophen (form III) has been found after different crystallization methods and the cooling rates, but the ambiguous explanations due to various differential scanning calorimetry (DSC) curves obtained have caused argument. [8][9][10][11] In the present study, a simple, quick and timesaving tool of Fourier transform infrared (FT-IR) microspectroscopy equipped with a micro hot stage (thermal FT-IR microscopic system) was used to readily and exactly explain the phase transition of metastable forms of acetaminophen by one-step process, as compared with different DSC thermograms of acetaminophen polymorphs prepared by different methods. ExperimentalMaterials Acetaminophen was of pharmaceutical grade, purchased from Seven Star Pharm. Co., Ltd. Taiwan, ROC. It was first recrystallized from aqueous solution, and then stored at 25°C, 75% relative humidity (RH) for further use. KBr crystal was of analytical IR grade, purchased from Jasco Co., Tokyo, Japan.Thermal FT-IR Microspectroscopic Study The acetaminophen powder was sandwiched between two KBr pieces by a hydraulic press to form a disc. This sample disc was directly put on a micro hot stage (DSC microscopy cell, FP 84, Mettler, Switzerland). The cell was then set on the stage of the microscope installed in the FT-IR microscopic spectrophotometer (Micro FTIR-200, Jasco, Tokyo, Japan) with an MCT detector. The system was operated in the transmission mode. The desired sample size for determination was selected and defined by means of an Aperture Through Optical System (ATOS) using microscope. The temperature of DSC microscopy cell was monitored with a central processor (FT80HT, Mettler, Switzerland). The heating rate of DSC assembly was controlled at 3°C/min in ambient conditions. The sample disc was previously equilibrated at the starting temperature (25°C) for about 3 min and then heated to 200°C. The thermal-responsive IR spectra were recorded with respect to the temperature. After the first heating process, the sample disc was cooled to 25°C and then re-heated from 25 to 200°C in the same conditions. Preparation and Determination of Diff...

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Section: Resultsmentioning

confidence: 99%

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confidence: 99%

Transformation of Metastable Forms of Acetaminophen Studied by Thermal Fourier Transform Infrared (FT-IR) Microspectroscopy.

2002

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“…Compressibility of a material is its ability to be reduced in volume as a result of an applied 333 pressure (Joiris et al, 1998). The compressibility profiles showed similar trends as tabletability, 334 with physical mixtures having greater compressibility (i.e.…”

Section: Compressibility 332mentioning

confidence: 97%

“…Tabletability describes the relationship between tensile strength of a tablet and compaction 276 pressure exerted on these tablets (Fig.3) (Joiris et al, 1998). A strong increase of tablet 277 strength was observed at low compaction pressures for most mixtures, however the curves 278 leveled off at higher compaction pressures.…”

Section: Tabletability 275mentioning

confidence: 99%

“…Since compactibility can be used to quantify bonding strength between particles at zero 369 porosity (Joiris et al, 1998;Maarschalk et al, 1996;Sun, 2011), these results suggested that 370 the higher tensile strength was more related to the interparticulate bonding area (i.e. 371 compressibility) compared to the bonding strength per unit bonding area (i.e.…”

Section: Compactibility 363mentioning

confidence: 99%

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The impact of hot-melt extrusion on the tableting behaviour of polyvinyl alcohol

Grymonpré

Jaeghere

Peeters

et al. 2016

International Journal of Pharmaceutics

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30There is evidence that processing techniques like hot-melt extrusion (HME) could alter the 31 mechanical properties of pharmaceuticals, which may impede further processability (e.g. 32 tableting). The purpose of this study was to evaluate if HME has an impact on the tableting 33 behavior of polyvinyl alcohol (PVA) -formulations. Mixtures of partially hydrolysed PVA grades 34 (with a hydroxylation degree of 75 and 88%) and sorbitol (0, 10 and 40%) were extruded, (cryo-) 35 milled and compressed into compacts of 350±10 mg. Before compression all intermediate 36 products were characterized for their solid-state (T g , T m , crystallinity) and material properties 37 (particle size, moisture content, moisture sorption). Because both PVA-grades required higher 38 extrusion temperatures (>180 °C), sorbitol was added to PVA as plasticizing agent to allow 39 extrusion at 140°C. Compaction experiments were performed on both physical mixtures and 40 cryo-milled extrudates of PVA-sorbitol. By measuring tablet tensile strength and porosity in 41 function of compaction pressure, tableting behavior was compared before and after HME by 42 means of the CTC-profiles (compressibility, tabletability, compactibility). A higher amorphous 43 content in the formulation (as a result of HME) negatively influenced the tableting behavior (i.e. 44 lower tablet tensile strength). HME altered the mechanical properties towards more elastically 45 deforming materials, thereby increasing tablet elastic recovery during decompression. The 46 lower tensile strengths resulted from a combined effect of less interparticulate bonding areas 47 (because of higher elastic recovery) and weaker bonding strengths per unit bonding area 48 (between glassy particles). 49 50 51 Keywords: hot-melt extrusion, tableting, elastic recovery, polyvinyl alcohol, oral drug delivery, 52 immediate release. 53 3

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Energy/Temperature Diagram and Compression Behavior of the Polymorphs of d-Mannitol

Burger

Henck

Hetz

et al. 2000

Journal of Pharmaceutical Sciences

321

230

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Abstract: Unlike the monoclinic form, orthorhombic paracetamol is suitable for the direct compression process. The crystalline structure accounts for its better compression behavior, because of the presence of sliding planes.

Cited by 259 publications

References 3 publications

Transformation of Metastable Forms of Acetaminophen Studied by Thermal Fourier Transform Infrared (FT-IR) Microspectroscopy.

Transformation of Metastable Forms of Acetaminophen Studied by Thermal Fourier Transform Infrared (FT-IR) Microspectroscopy.

The impact of hot-melt extrusion on the tableting behaviour of polyvinyl alcohol

Energy/Temperature Diagram and Compression Behavior of the Polymorphs of d-Mannitol

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