Sustained release properties of crosslinked and substituted starches

Abstract

High amylose corn, waxy corn, and potato starches were crosslinked (XL) to an optimal degree and then substituted with carboxymethyl (CM) and aminoethyl (AE) groups, and their drug release properties, swelling power, and potential interactions with drugs were investigated. Propranolol hydrochloride, sodium diclofenac and acetaminophen were used as model drugs. High amylose starch required a higher XL degree to achieve good sustained release properties, whereas waxy corn required the least XL. Drug release was more governed by the matrix characteristics than by drug properties, and XL-CM high amylose corn starch displayed a nearly constant drug release for all three drugs tested. Swelling power correlated well with sustained release properties with the better matrices swelling to greater extents. There was a potential interaction between XL-AE-starches and diclofenac as indicated by differential scanning calorimetry. Starches from different sources require different types and degrees of modifications to achieve satisfactory sustained release. V C 2010 Wiley Periodicals, Inc. J Appl

Functional and Tableting Properties of Alkali-Isolated and Phosphorylated Barnyard Millet (Echinochloa esculenta) Starch

“…The angle of repose and bulk characteristics like the Carr index and the Hausner ratio are frequently used to detect powder flow . The angle of repose of phosphorylated zhingora starch (PZS) and alkali-extracted zhingora starch (AZS) powders was determined to assess the flow properties. , A funnel was positioned at a height ( h ) that was preset above a graph paper that was laid out horizontally on a platform that was leveled. A conical mound of powdered PZS stood at the top of the funnel’s tip.…”

“…Additionally, alkaline treatment has found applications in starch-based adhesive manufacturing and is known for yielding high-purity starch granules with well-defined physical features . However, most studies in the pharmaceutical field have been focused on starch derived from commonly used sources such as corn, rice, potatoes, wheat, and cassava. ,, Polysaccharides such as starch, however, have unfavorable properties such as poor shear strength, ease of heat disintegration, and a high tendency for delignification (crystallization and gel aging), digestibility, glycemic index, film-forming properties, and paste clarity thus limiting their use. − The physical, chemical, and enzymatic modification methods have been used to improve starch functionality. − By applying grafting processes such as oxidation, etherification, esterification, or cross-linking, polysaccharides can have altered structures and characteristics. , The structure, properties, and characteristics of starch can also be altered through grafting reactions, oxidation, etherification, esterification, and cross-linking. , Cross-linking can be produced by di-esters between the starch chains and molecules. The cross-linking is supposed to insert inter- and intramolecular bonds at different sites in starch molecules for triggering the strength of starch.…”

“… 13 − 15 By applying grafting processes such as oxidation, etherification, esterification, or cross-linking, polysaccharides can have altered structures and characteristics. 16 , 17 The structure, properties, and characteristics of starch can also be altered through grafting reactions, oxidation, etherification, esterification, and cross-linking. 17 , 18 Cross-linking can be produced by di-esters between the starch chains and molecules.…”

Starch-based microspheres for sustained-release of curcumin: Preparation and cytotoxic effect on tumor cells

“…All this disadvantages limit its clinical application. One way to overcome these limitations and improve the oral bioavailability of CUR is to encapsulate it into a polymeric matrix, which acts as a device for controlling the drug release (Mohanty & Sahoo, 2010;Onofre & Wang, 2010). This is a well-known strategy that has been explored by several studies (Anand et al, 2007;Shaikh, Ankola, Beniwal, Singh, & Kumar, 2009).…”

Application of freeze-drying in the development of oral drug delivery systems

“…Modified polysaccharides and coprocessed polymers have improved functionalities that serve as an alternative matrix excipient for controlled-release preparations. For example, pregelatinized starch is known to be a better release-control agent than native or other chemically modified starches as it readily forms an obstructive gel layer on tablet surfaces when in contact with water [71].…”