An investigation into the thermal behaviour of a model drug mixture with amorphous trehalose

Horvat, Michaela; Meštrović, Ernest; Danilovski, Aleksandar; Craig, Duncan Q.M.

doi:10.1016/j.ijpharm.2004.08.025

Cited by 12 publications

(11 citation statements)

References 15 publications

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“…The peaks represented that the raw trehalose dihydrate was highly crystalline which is in a good agreement with the University of Cambridge database and by results reported by Mansour et al (29). The loss of characteristic crystalline peaks ("halo") is in good agreement with previous reports on aqueous solution spray-dried trehalose under different conditions (34).…”

Section: Powder X-ray Diffractionsupporting

confidence: 91%

Physicochemical Characterization and Water Vapor Sorption of Organic Solution Advanced Spray-Dried Inhalable Trehalose Microparticles and Nanoparticles for Targeted Dry Powder Pulmonary Inhalation Delivery

Mansour

2011

AAPS PharmSciTech

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Abstract. Novel advanced spray-dried inhalable trehalose microparticulate/nanoparticulate powders with low water content were successfully produced by organic solution advanced spray drying from dilute solution under various spray-drying conditions. Laser diffraction was used to determine the volumetric particle size and size distribution. Particle morphology and surface morphology was imaged and examined by scanning electron microscopy. Hot-stage microscopy was used to visualize the presence/absence of birefringency before and following particle engineering design pharmaceutical processing, as well as phase transition behavior upon heating. Water content in the solid state was quantified by Karl Fisher (KF) coulometric titration. Solidstate phase transitions and degree of molecular order were examined by differential scanning calorimetry (DSC) and powder X-ray diffraction, respectively. Scanning electron microscopy showed a correlation between particle morphology, surface morphology, and spray drying pump rate. All advanced spray-dried microparticulate/nanoparticulate trehalose powders were in the respirable size range and exhibited a unimodal distribution. All spray-dried powders had very low water content, as quantified by KF. The absence of crystallinity in spray-dried particles was reflected in the powder X-ray diffractograms and confirmed by thermal analysis. DSC thermal analysis indicated that the novel advanced spray-dried inhalable trehalose microparticles and nanoparticles exhibited a clear glass transition (T g ). This is consistent with the formation of the amorphous glassy state. Spray-dried amorphous glassy trehalose inhalable microparticles and nanoparticles exhibited vapor-induced (lyotropic) phase transitions with varying levels of relative humidity as measured by gravimetric vapor sorption at 25°C and 37°C.

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Section: Powder X-ray Diffractionsupporting

confidence: 91%

Physicochemical Characterization and Water Vapor Sorption of Organic Solution Advanced Spray-Dried Inhalable Trehalose Microparticles and Nanoparticles for Targeted Dry Powder Pulmonary Inhalation Delivery

Mansour

2011

AAPS PharmSciTech

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“…2b) can be ascribed to enthalpy relaxation of the polymer [22] while the second endotherm can be ascribed to the polymer melting [23]. The endothermic and exothermic transitions of metronidazole ( fig.…”

Section: Discussionmentioning

confidence: 97%

“…2e). The endothermic transition can be ascribed to melting of the drug [23] while the exothermic transition can be ascribed to degradation [24].…”

Section: Discussionmentioning

confidence: 99%

Evaluation of Callinectes Chitosan as a Superdisintegrant in Metronidazole Tablet

Olorunsola

Adedokun

Akpabio

2017

Int J Pharm Pharm Sci

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Objective: The objective of this study is to evaluate callinectes chitosan as a superdisintegrant in tablet formulation; superdisintegrants are incorporated into tablets at concentrations below 5% of tablet weight to effect prompt break-up of tablets after administration. Methods:Chitosan was extracted from shells of Callinectes gladiator. The polymer was characterized and then used as a disintegrant (in comparison with Ac-Di-Sol ® and corn starch) at concentrations of 2, 4 and 8% for the formulation of metronidazole tablets. The micromeritic properties of granules; and mechanical and release properties of the tablets were studied.Results: A yield of 36.7% chitosan having degree of deacetylation of 62.7% was obtained from the crab shell. Fourier Transform Infrared absorption bands at 1495 and 3240 cm -1 typical of N-H bending and stretching respectively; and endothermic peak of 159 °C typical of melting of chitosan were obtained. No adverse interaction between the chitosan and metronidazole was observed. The disintegration times of tablets containing 2, 4 and 8% chitosan were 12.2, 10.4 and 9.3 min respectively. Conclusion:Callinectes chitosan is suitable for use as a superdisintegrant in tablets. It appears to be superior to corn starch as disintegrant although less effective compared to Ac-Di-Sol ® . However, the relative cheapness and ready availability of chitosan would make it to be preferred to Ac-Di-Sol ® .

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“…The diffuse endotherm of chitosan which peaked at 54.8°C can be ascribed to loss of the absorbed water (Horvat et al, 2005); and 632.5 J of heat per gram sample of the polymer was absorbed in the process. The second transition (with peak at 107.2°C) is a relaxation endotherm (Chung et al, 2002) with enthalpy of 771.5 J/g.…”

Section: Discussionmentioning

confidence: 99%

“…The second transition (with peak at 107.2°C) is a relaxation endotherm (Chung et al, 2002) with enthalpy of 771.5 J/g. Endothermic relaxation is a second order reaction just like glass transition (Horvat et al, 2005). The third endotherm can be ascribed to polymer melting.…”

Section: Discussionmentioning

confidence: 99%

Extraction and physicochemical characterization of a potential multifunctional pharma-excipient from crab shell wastes

Olorunsola¹,

Olayemi²,

Majekodunmi³

et al. 2015

Afr. J. Biotechnol.

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An efficient and beneficial waste disposal mechanism is highly desired. This study was carried out to extract and characterize a potential multifunctional pharmaceutical excipient from crab shell wastes. Shells of Pachygrapsus mamoratus were obtained from Oron, a coastal town in Akwa Ibom State of Nigeria. Chitin was extracted from the powdered shell by deproteination and demineralization; and chitosan was derived by alkaline deacetylation of the chitin. The polymer was subjected to Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC). It was also evaluated for flow properties, pH and hydration and swelling characteristics. The shells gave a yield of 17% chitosan. FTIR analysis of the polymer showed C-H bond of substituted cyclic hydrocarbon, cyclic C-N bond, C-O bond of glucose molecules, C-H bond of side chain -CH 2 OH, presence of β-ester linkage, N-H of amides and bonded and free O-H groups. The last transition in the thermogram of chitosan was a polymer degradation exotherm with a peak at 337.9°C. The chitosan had higher bulk density, higher flow rate, lower Carr's index and lower Hausner's ratio compared to sodium carboxymethylcellulose. It also had lower hydration and swelling capacities. Therefore, the crab shell-derived chitosan has better thermal stability, better flow properties but poorer swelling properties compared to sodium carboxymethylcelluose.

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An investigation into the thermal behaviour of a model drug mixture with amorphous trehalose

Cited by 12 publications

References 15 publications

Physicochemical Characterization and Water Vapor Sorption of Organic Solution Advanced Spray-Dried Inhalable Trehalose Microparticles and Nanoparticles for Targeted Dry Powder Pulmonary Inhalation Delivery

Physicochemical Characterization and Water Vapor Sorption of Organic Solution Advanced Spray-Dried Inhalable Trehalose Microparticles and Nanoparticles for Targeted Dry Powder Pulmonary Inhalation Delivery

Evaluation of Callinectes Chitosan as a Superdisintegrant in Metronidazole Tablet

Extraction and physicochemical characterization of a potential multifunctional pharma-excipient from crab shell wastes

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