Adsorptive crystallization of benzoic acid in aerogels from supercritical solutions

Gorle, B. S. K.; Смирнова, Ирина; Arlt, Wolfgang

doi:10.1016/j.supflu.2010.01.006

Cited by 42 publications

(22 citation statements)

References 29 publications

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“…Specific loading 252 values for ketoprofen were lower than those expected for a monolayer coverage (1.7-2.1×10 -3 g/m 2 ) in 253 all cases. Ketoprofen adsorption coverages in the aerogels below the monolayer coverage might be 254 explained by surface hydroxyl group density in the aerogel and the competitive physisorption of CO 2 255 molecules during the supercritical fluid-assisted impregnation process (Gorle, Smirnova & Arlt, 2010; 256…”

Section: Drug Entrapment Efficiency 238mentioning

confidence: 99%

Polysaccharide-based aerogel microspheres for oral drug delivery

García‐González

Jin

Gerth

et al. 2015

Carbohydrate Polymers

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Polysaccharide-based aerogels in the form of microspheres were investigated as carriers of poorly water soluble drugs for oral administration. These bio-based carriers may combine the biocompatibility of polysaccharides and the enhanced drug loading capacity of dry aerogels. Aerogel microspheres from starch, pectin and alginate were loaded with ketoprofen (anti-inflammatory drug) and benzoic acid (used in the management of urea cycle disorders) via supercritical CO2-assisted adsorption. Amount of drug loaded depended on the aerogel matrix structure and composition and reached values up to 1.0×10-3 and 1.7×10-3 g/m2 for ketoprofen and benzoic acid in starch microspheres. After impregnation, drugs were in the amorphous state in the aerogel microspheres. Release behavior was evaluated in different pH media (pH 1.2 and 6.8). Controlled drug release from pectin and alginate aerogel microspheres fitted Gallagher-Corrigan release model (R2>0.99 in both cases), with different relative contribution of erosion and diffusion mechanisms depending on the matrix composition. Release from starch aerogel microspheres was driven by dissolution, fitting the first-order kinetics due to the rigid starch aerogel structure, and showed different release rate constant (k1) depending on the drug (0.075 and 0.160 min-1 for ketoprofen and benzoic acid, respectively). Overall, the results point out the possibilities of tuning drug loading and release by carefully choosing the polysaccharide used to prepare the aerogels. HIGHLIGHTS-Polysaccharide aerogel microspheres are investigated as carriers of drugs for oral administration -Aerogels were loaded with ketoprofen and benzoic acid, poorly water soluble model drugs -Starch, with the lowest specific surface area, was more prone to adsorb drug molecules -Release of ketoprofen from alginate and pectin aerogel particles was sensitive to pH of the medium -Results point out the possibilities of polysaccharide aerogels of tuning drug loading and release Polysaccharide-based aerogels in the form of microspheres were investigated as carriers of poorly 19 water soluble drugs for oral administration. These bio-based carriers may combine the 20 biocompatibility of polysaccharides and the enhanced drug loading capacity of dry aerogels. Aerogel 21 microspheres from starch, pectin and alginate were loaded with ketoprofen (anti-inflammatory drug) 22and benzoic acid (used in the management of urea cycle disorders) via supercritical CO 2 -assisted 23 adsorption. Amount of drug loaded depended on the aerogel matrix structure and composition and 24 reached values up to 1.0×10 -3 and 1.7×10 -3 g/m 2 for ketoprofen and benzoic acid in starch 25 microspheres. After impregnation, drugs were in the amorphous state in the aerogel microspheres. 26Release behavior was evaluated in different pH media (pH 1.2 and 6.8). Controlled drug release from 27 pectin and alginate aerogel microspheres fitted Gallagher-Corrigan release model (R 2 >0.99 in both 28 cases), with different relative contribution of erosion and...

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Section: Drug Entrapment Efficiency 238mentioning

confidence: 99%

Polysaccharide-based aerogel microspheres for oral drug delivery

García‐González

Jin

Gerth

et al. 2015

Carbohydrate Polymers

Self Cite

259

147

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show abstract

“…Hence, XRD and DSC results suggested that the drug was 233 most likely dispersed inside the matrices at a molecular level, rather than in the crystalline or amorphous solid form (Kazarian and Martirosyan, 2002;López-234 Periago et al, 2009). In fact, to generate crystalline particles inside of the pores a sudden change in solubility, created, for instance, by fast pressure release, 235 has been described as necessary (Gorle et al, 2010). 236…”

mentioning

confidence: 99%

Hybrid aerogel preparations as drug delivery matrices for low water-solubility drugs

Veres

López‐Periago

Lázár

et al. 2015

International Journal of Pharmaceutics

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“…This was proven experimentally for a number of drugs and is exemplarily demonstrated in Figure 31.6 for ketoprofen. Also the adsorption of pure solvent -in this case CO 2 -is influenced by the esterification of the aerogels in the same manner [12]. It should also be noted that a considerable amount of CO 2 is adsorbed on the aerogel even in comparison to standard adsorbents, such as zeolites and activated carbon (Figure 31.7).…”

Section: Release Of the Drugs From Silica Aerogelsmentioning

confidence: 89%

“…Furthermore, the main problem of the handling of small particles, their agglomeration, can be avoided since the particles are separated from each other by the walls of the pores. Precipitation of solutes inside the pores of silica aerogels should be controlled not only by process parameters, such as pressure, temperature, and bulk concentration of the target compound, but also, at a more fundamental level, by the physico-chemical properties of the carrier aerogels [12]. Thus, a fundamental understanding of the effect of the adsorptive properties of the carrier (silica aerogels) on the crystallization or precipitation of solute in its pores is needed.…”

Section: Crystallization/precipitation Of Drugs In Aerogelsmentioning

confidence: 99%

“…Thus, a fundamental understanding of the effect of the adsorptive properties of the carrier (silica aerogels) on the crystallization or precipitation of solute in its pores is needed. Recently, a term "adsorptive crystallization" was introduced to describe this process [9,12], which is discussed as a tool to adjust the loading and physical state of solutes/drugs, for the future potential applications in pharmaceutical, food, storage, and other related industries. Especially, for the pharmaceutical industry, the bioavailability of the drug is an important factor, which is influenced by the state of the drug, i.e., amorphous forms of drugs have higher bioavailability compared to their corresponding crystalline form.…”

Section: Crystallization/precipitation Of Drugs In Aerogelsmentioning

confidence: 99%

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Pharmaceutical Applications of Aerogels

Смирнова

2011

Aerogels Handbook

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At present, an interest has grown in the field of biocompatible aerogels and composite aerogel materials in life science, especially in biomedical and pharmaceutical applications. Due to their large surface area, open pore structure, and biocompatibility, aerogels are very promising candidates for drug delivery systems. The use of both inorganic and organic aerogels as carriers for pharmaceutically active compounds is discussed in this chapter. Both the stability and the release kinetics of the drug can be significantly improved by loading them into aerogels. First attempts to prepare semisolid and solid pharmaceutical formulations have been made. Furthermore, aerogels can be used as a host matrix for bioactive compounds (enzymes and proteins), which improve or enable their performance. Taking into account all research activities in the area of aerogels, a number of promising pharmaceutical applications can be expected in future. IntroductionSilica aerogels were used in daily life products since 1960s, when Monsanto's aerogels were introduced as additives for cosmetics and toothpaste. At present, an interest has grown in the field of biocompatible aerogels and composite aerogel materials in life sciences, especially for biomedical and pharmaceutical applications. In principle, biocompatible aerogels can be made from any organic compound, whose properties such as toxicity and biodegradation are suitable for the given application. In the case of aerogel composites, the final material consists of an aerogel matrix and one or more additional phases (of any composition or scale), which influence the properties of the final product. Thus, at least one phase has a physical structure with dimensions in the order of nanometres (the particles and pores of the aerogel). The aerogel composites can be prepared in two different ways: through the addition of a target compound during the sol-gel process (Figure 31.1A) and by post-treatment of the dried aerogels (Figure 31.1B), for example, by adsorption, vapour phase deposition, or reactive gas treatment.The first method (a) is attractive by its simplicity and flexibility, since virtually every material can be easily added to the sol solution before gelation. This added material can be of I. Smirnova

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Adsorptive crystallization of benzoic acid in aerogels from supercritical solutions

Cited by 42 publications

References 29 publications

Polysaccharide-based aerogel microspheres for oral drug delivery

Polysaccharide-based aerogel microspheres for oral drug delivery

Hybrid aerogel preparations as drug delivery matrices for low water-solubility drugs

Pharmaceutical Applications of Aerogels

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