Himansu Sekhar Nanda; Naoki Kawazoe; Guoping Chen
Abstract
Biodegradable polymeric microspheres have been used for microencapsulation of number of drugs for controlled delivery applications. Water-in-oil-in-water (w/o/w) double emulsion has been employed for preparation of drug incorporated poly(lactic-co-glycolic acid) (PLGA) microspheres. In the present ...
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Biodegradable polymeric microspheres have been used for microencapsulation of number of drugs for controlled delivery applications. Water-in-oil-in-water (w/o/w) double emulsion has been employed for preparation of drug incorporated poly(lactic-co-glycolic acid) (PLGA) microspheres. In the present study, existing double emulsion method was modified by introducing ionic salt in continuous phase of emulsion process. Insulin incorporated microspheres were prepared from wide range of PLGA concentrations under an identical preparation condition and the influence of varied concentration of salt on microsphere characteristics was studied. The results demonstrated, the degree of solidification of PLGA was controlled using ionic salt and the prepared formulations showed improved morphology, enhanced encapsulation efficiency and a positive modulation over the drug release characteristic compared to control. The modified method should be useful for elimination of highly porous and collapsed microspheres in the formulations prepared from low range PLGA concentration and should pave the way to improve several microsphere formulations for controlled drug delivery applications.
Gunther S.V; Dambaev G.Ts; Chekalkin T.L; Kang J-H; Kim J-S; Gunther V.E
Abstract
Despite the prescribed benefits of insulin widely used in treating diabetes, patients still feel the inconvenience and perceived pain related to multiple daily administrations by needle insulin injections. Approved inhaled insulin of the second generation has not so far achieved expectations. Design ...
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Despite the prescribed benefits of insulin widely used in treating diabetes, patients still feel the inconvenience and perceived pain related to multiple daily administrations by needle insulin injections. Approved inhaled insulin of the second generation has not so far achieved expectations. Design of needle-free delivery systems for insulin is an active area of research and this paper reports on the development of a new needle-free approach to deliver insulin treating diabetes. Porous TiNi-based alloys serve as high-density materials being capable of holding insulin solutions within the structure of the material, and infrared radiation promotes the directional diffusion of insulin from the TiNi porous structure into the skin. Taking these two facts into account, the needle-free device (NFD) for delivering insulin uses a new porous-permeable TiNi-based material and a novel infrared radiation mediated delivery system. The NFD described causes no skin irritation or lesions and is safe to use in practice. Its efficiency in delivering insulin was clinically assessed on 42 diabetic patients. The results show promising prospects as a new technology for delivering insulin and other liquid drugs.
Songjun Lia; Ashutosh Tiwari; Yi Gec; Dan Fei
Abstract
A new type of insulin delivery system capable of better self-regulating the release of insulin was reported in this study. This insulin delivery system was made of a low crosslinked insulin-imprinted hydrogel that exhibited pH-dependent interpolymer interactions between poly(methacrylic acid) (PMAA) ...
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A new type of insulin delivery system capable of better self-regulating the release of insulin was reported in this study. This insulin delivery system was made of a low crosslinked insulin-imprinted hydrogel that exhibited pH-dependent interpolymer interactions between poly(methacrylic acid) (PMAA) and poly(ethylene glycol) (PEG). At acidic conditions (such as pH 3.5), this delivery system resembled a highly crosslinked imprinted hydrogel and demonstrated a relatively slow release due to the formation of the PMAA-PEG complexes, which significantly increased physical crosslinking within the hydrogel interior and largely fixed the imprinted networks. On the contrary, at neutral or basic conditions (such as pH 7.4), this delivery system was comparable to a non-imprinted hydrogel and caused a rapid release resulting from the dissociation of the PMAA-PEG complexes. Unlike previously reported non-imprinted hydrogels and highly crosslinked imprinted polymers, which lack either molecular recognition ability or switchable imprinted networks, this unique insulin delivery system was composed of tunable and low crosslinked imprinted networks, which thereby enabled better self-regulation of insulin delivery.