The importance of surface energetics of powders for drug delivery and the establishment of inverse gas chromatography

Buckton, Graham; Gill, Hardyal

doi:10.1016/j.addr.2007.06.017

Cited by 54 publications

(41 citation statements)

References 28 publications

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“…Various methods have been used to estimate the surface energies of these systems, including contact angle methods, inverse gas chromatography, atomic force microscopy, etc. (11)(12)(13). Each technique has its own advantages and disadvantages.…”

Section: Introductionmentioning

confidence: 99%

Surface Thermodynamics of Mucoadhesive Dry Powder Formulation of Zolmitriptan

et al. 2011

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Abstract. Microparticle powders for nasal delivery were formulated to contain the model drug, zolmitriptan, and varying proportions of different polymers. The objective of the study was to investigate the effects of these formulative parameters on the surface chemistry of the spray-dried microparticles and their potential for adhesion to the tested substrates, porcine mucin, and nasal tissue. The polymers used were chitosans of varying ionization states and molecular weights and hydroxypropyl methyl cellulose. The surface energies of the surfaces of the microparticles were determined using contact angle measurements and the van Oss model. The theory of surface thermodynamics was applied to determine the theoretical potential for the different materials to adhere to the substrates. It was found that the drug or polymers alone, as well as the various formulations, were more likely to adhere to mucin than to nasal tissue. Further, there was a trend for higher molecular weight chitosans to adhere better to the substrates than lower molecular weight chitosans. Similarly, adhesion was improved for formulations with a higher content of polymers. These theoretical predictions may be compared with further experimental results and be of use in making informed decisions on the choice of formulations for future expensive bio-studies.

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Section: Introductionmentioning

confidence: 99%

Surface Thermodynamics of Mucoadhesive Dry Powder Formulation of Zolmitriptan

et al. 2011

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“…1) which was derived from a force balance acting at the threephase contact point: γ is the solid-liquid surface energy, and Y θ is the Young contact angle. Measurements of contact angle can be performed on compressed powder surfaces, powder adhered to a glass slide or Wilhelmy plate methods on compressed plates, but these methods have significant limitations in the accurate assessment of surface energy (9). An alternative approach is to conduct sessile drop contact angle measurements on surfaces of macroscopic crystals to derive surface energetic information (10).…”

Section: Introductionmentioning

confidence: 99%

“…Experiments in IGC are conducted by packing the solid sample of interest in a column and then injecting known vapour probes into the column via an inert carrier gas to probe the physiochemical properties of the sample. The determination of the dispersive surface energy, d SV γ , and acid-base adsorption energy, 0 AB G ∆ , as well as the basic and acidic properties of the solid samples are well documented (9,12). The usual procedure of measuring surface energies by IGC is at infinite dilution where very small concentrations of probe vapours (<0.03 p/p 0 ) are injected.…”

Section: Introductionmentioning

confidence: 99%

Determination of surface heterogeneity of d-mannitol by sessile drop contact angle and finite concentration inverse gas chromatography

Hinder

Watts

et al. 2010

International Journal of Pharmaceutics

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“…Several approaches have been used to measure the surface energy of powders. The liquid and vapour probe techniques, contact angle and inverse gas chromatography (IGC), respectively, are probably the most popular choices (10,11). Different methods of measurement could result in varied surface energy values for a specific material (12).…”

Section: Introductionmentioning

confidence: 99%

Theophylline Cocrystals Prepared by Spray Drying: Physicochemical Properties and Aerosolization Performance

et al. 2013

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Abstract. The purpose of this work was to characterize theophylline (THF) cocrystals prepared by spray drying in terms of the physicochemical properties and inhalation performance when aerosolized from a dry powder inhaler. Cocrystals of theophylline with urea (THF-URE), saccharin (THF-SAC) and nicotinamide (THF-NIC) were prepared by spray drying. Milled THF and THF-SAC cocrystals were also used for comparison. The physical purity, particle size, particle morphology and surface energy of the materials were determined. The in vitro aerosol performance of the spray-dried cocrystals, drug-alone and a drugcarrier aerosol, was assessed. The spray-dried particles had different size distributions, morphologies and surface energies. The milled samples had higher surface energy than those prepared by spray drying. Good agreement was observed between multi-stage liquid impinger and next-generation impactor in terms of assessing spray-dried THF particles. The fine particle fractions of both formulations were similar for THF, but drug-alone formulations outperformed drug-carrier formulations for the THF cocrystals. The aerosolization performance of different THF cocrystals was within the following rank order as obtained from both drug-alone and drug-carrier formulations: THF-NIC>THF-URE>THF-SAC. It was proposed that micromeritic properties dominate over particle surface energy in terms of determining the aerosol performance of THF cocrystals. Spray drying could be a potential technique for preparing cocrystals with modified physical properties.

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The importance of surface energetics of powders for drug delivery and the establishment of inverse gas chromatography

Cited by 54 publications

References 28 publications

Surface Thermodynamics of Mucoadhesive Dry Powder Formulation of Zolmitriptan

Surface Thermodynamics of Mucoadhesive Dry Powder Formulation of Zolmitriptan

Determination of surface heterogeneity of d-mannitol by sessile drop contact angle and finite concentration inverse gas chromatography

Theophylline Cocrystals Prepared by Spray Drying: Physicochemical Properties and Aerosolization Performance

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