Evaluation of olibanum resin as microencapsulating agent for controlled drug delivery

Chowdary, K. P. R.; Mohapatra, Prithwiraj; Krishna, M. N. Murali

doi:10.4103/0250-474x.27818

Cited by 14 publications

(10 citation statements)

References 1 publication

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“…The values of Higuchi rate constant (K H ) were found to range between 16.1 to 23.3 %h -1/2 with a distinct increasing trend as the cellulose acetate levels in the cores decreased. The effect of varying cellulose acetate levels in matrix diffusional systems on drug release has been documented 9 .…”

Section: Resultsmentioning

confidence: 99%

Design and evaluation of controlled onset extended release multiparticulate systems for chronotherapeutic delivery of ketoprofen

2006

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An oral controlled onset extended release dosage form intended to approximate the chronobiology of rheumatoid arthritis is proposed for site-specific release to the colon. The multiparticulate system consisting of drug-loaded cellulose acetate cores encapsulated within Eudragit S-100 microcapsules was designed for chronotherapeutic delivery of ketoprofen. Drug-loaded cellulose acetate cores were prepared by emulsion solvent evaporation technique in an oily phase at different drug:polymer ratios (1:1, 2:1 and 4:1). These cores were successfully microencapsulated with Eudragit S-100 following the same technique at the core:coat ratio of 1:5. Scanning electron microscopy (SEM) revealed that the cellulose acetate cores were discrete, uniform and spherical with a porous and rough surface, whereas the Eudragit microcapsules were discrete and spherical with a smooth and dense surface. In vitro drug release studies of the Eudragit microcapsules were performed in different pH conditions following pHprogression method for a period of 16 h. The release studies indicated that the microcapsules posses both pHsensitive and controlled-release properties, showing limited drug release below pH 7.0 (6.40 to 8.94%), following which the cellulose acetate cores effectively controlled the drug release for a period of 11 h in pH 7.5. The differential scanning calorimetric and powder X-ray diffraction studies demonstrated that ketoprofen was present in dissolved state in the cellulose acetate polymeric matrix, which could explain the controlled drug release from the cores. The release of ketoprofen from Eudragit microcapsules in pH 7.5 depended on the cellulose acetate levels and was characterized by Higuchi's diffusion model.

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Section: Resultsmentioning

confidence: 99%

Design and evaluation of controlled onset extended release multiparticulate systems for chronotherapeutic delivery of ketoprofen

2006

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“…8,9 However, encapsulation devices introduce a transport barrier between the host and graft tissues and inherently limit oxygen supply, compromising graft function and cell viability, 10 problems that scale with device wall thickness. 11,12 Typically grafts are implanted in subcutaneous 13 or intraperitoneal 14 sites where partial pressures of oxygen (pO 2 ) are approximately 60 and 40 mm Hg, respectively, which is lower than that of arterial blood (>80 mm Hg). It is commonly asserted that low cell viability within devices 15,16 results from low tissue oxygen taken together with device diffusional barriers to create hypoxic and anoxic conditions, where these conditions are known to promote cell death through necrosis and apoptosis.…”

Section: Introductionmentioning

confidence: 99%

Method measuring oxygen tension and transport within subcutaneous devices

et al. 2014

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Abstract. Cellular therapies hold promise to replace the implantation of whole organs in the treatment of disease. For most cell types, in vivo viability depends on oxygen delivery to avoid the toxic effects of hypoxia. A promising approach is the in situ vascularization of implantable devices which can mediate hypoxia and improve both the lifetime and utility of implanted cells and tissues. Although mathematical models and bulk measurements of oxygenation in surrounding tissue have been used to estimate oxygenation within devices, such estimates are insufficient in determining if supplied oxygen is sufficient for the entire thickness of the implanted cells and tissues. We have developed a technique in which oxygen-sensitive microparticles (OSMs) are incorporated into the volume of subcutaneously implantable devices. Oxygen partial pressure within these devices can be measured directly in vivo by an optical probe placed on the skin surface. As validation, OSMs have been incorporated into alginate beads, commonly used as immunoisolation devices to encapsulate pancreatic islet cells. Alginate beads were implanted into the subcutaneous space of Sprague-Dawley rats. Oxygen transport through beads was characterized from dynamic OSM signals in response to changes in inhaled oxygen. Changes in oxygen dynamics over days demonstrate the utility of our technology. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

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“…Olibanum resin coated microcapsules were formulated by emulsification solvent evaporation method. It was observed that drug release from the resin-coated microcapsules was slow over 24 hours and depended on core : coat ratio, wall thickness, and size of the microcapsules [76]. …”

Section: Some Recently Investigated Natural Gums and Mucilagesmentioning

confidence: 99%

Recently Investigated Natural Gums and Mucilages as Pharmaceutical Excipients: An Overview

Choudhary¹,

Pawar²

2014

Journal of Pharmaceutics

110

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Due to advances in drug delivery technology, currently, excipients are included in novel dosage forms to fulfil specific functions and in some cases they directly or indirectly influence the extent and/or rate of drug release and drug absorption. Recent trends towards use of plant based and natural products demand the replacement of synthetic additives with natural ones. Today, the whole world is increasingly interested in natural drugs and excipients. These natural materials have many advantages over synthetic ones as they are chemically inert, nontoxic, less expensive, biodegradable, and widely available. This review discusses majority of the plant-derived polymeric compounds (gums and mucilage's), their sources, chemical constituents, uses, and some recent investigations as excipients in novel drug delivery systems.

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Evaluation of olibanum resin as microencapsulating agent for controlled drug delivery

Cited by 14 publications

References 1 publication

Design and evaluation of controlled onset extended release multiparticulate systems for chronotherapeutic delivery of ketoprofen

Design and evaluation of controlled onset extended release multiparticulate systems for chronotherapeutic delivery of ketoprofen

Method measuring oxygen tension and transport within subcutaneous devices

Recently Investigated Natural Gums and Mucilages as Pharmaceutical Excipients: An Overview

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