Handbook of Vitamin C Research

Encapsulation Devices for Vitamin C 201Vitamin C/Eudragit® microspheres obtained by spray-drying method were unable toslow down the release of the drug with respect to the free form of ascorbic acid but thesemicrospheres showed a good morphology and size distribution that permit to propose them ascandidate for the delivery of vitamin C as associated therapy in the treatment of colorectalcancer by oral route [71].The procedure of obtaining microparticles with encapsulated ascorbic acid by spraydrying was described by Finotelli and co-workers [112]. The morphology of theCapsul/vitamin C particles was observed by a scanning electron microscopy, whose analysisshowed a tendency of agglomeration. Particle size analysis showed a multi-modal particlesize distribution, but with a main mode in intermediate diameters range (4–8 μm). Theparticle yield was 52%. Ascorbic acid stability was studied for particles stored, at both, roomtemperature and at 45°C showing 100% of retention at the beginning. Microcapsulescontaining 20% of ascorbic acid recovered by a mixture presented 7% of ascorbic acidreduction in samples for up to 60 days stored at 28°C temperature.Spray drying technique was also used by Desai and co-workers for encapsulation ofvitamin C in tripolyphosphate cross-linked chitosan microspheres [59, 116-118]. Resultsshowed a mean particle size of 6.1-9.0 µm which was influenced by the amount of crosslinkingagent. Encapsulation efficiency was around 58% but decreased as the amount oftripolyphosphate solution increased. The amount of crosslinking affected the release rate andparticle size.8. Applications of Micro and Nanoparticleswith Ascorbic AcidIn recent years, micro and nanoparticles have attracted considerable attention as potentialdrug delivery devices in view of their applications in the controlled release of drugs, theirability to target particular organs/tissues, as carriers of DNA in gene therapy, and in theirability to deliver divers drugs through a different route of administration [91].Encapsulation of vitamin C within micro or nanoparticles proposes many advantages.Primarily, encapsulation can help to stabilise vitamin C. Many studies have been done on thisvitamin with variables optimized to determine the most stable way of encapsulating vitaminC and to give the highest retention possible [87]. Particles containing encapsulated ascorbicacid can be used in numerous applications. Numerous products are using currently vitamin Cbecause of its significant properties, particularly its anti-oxidizing effect. Vitamin C hasability of quenching or stabilizing free radicals that lead over time to degenerative diseases,including cancer, cardiovascular disease, cataracts, and other diseases.PLGA nanospheres are very efficient mean of transdermal transport of medicaments inthe body, e.g. ascorbic acid [133, 134].Ascorbic acid providing photoprotective capabilities by inhibiting UVA and UVBradiation-induced damage by neutralizing the oxygen-free radicals in the skin, it prevents UVimmunosuppression, stimulates collagen synthesis and has anti-inflammatory properties [135,136]. Here, not only does encapsulation provide a convenient formulation vehicle, but it alsoenhanced the stability of the encapsulated payload at an elevated temperature.