Physicochemical and Pharmaceutical Properties of Cross‐Linked Carboxymethyl Rice Starch Prepared by a Simultaneous Dual Reaction

Abstract

Cereal Chem. 87(3):214-220Cross-linked carboxymethyl rice starches (CL-CMRS) were prepared from reactions between a native Klong Luang 1 (KL1) rice starch and varied concentrations (2.5-15% w/w) of sodium trimetaphosphate (STMP) in simultaneous carboxymethylation and cross-linking reactions set up using methanol as a solvent. Physicochemical as well as pharmaceutical properties of CL-CMRS were evaluated in relation to the amount of STMP used and the degree of cross-linking (DCx). At a low DCx, the viscosity of CMRS solution was enhanced through the formation of cross-linked polymeric network and chain entanglement. At higher concentrations in the preparation reaction, STMP caused proportional de-creases in the water solubility and ≤70-fold of the solution viscosity, but promoted swelling and water uptake of the modified starches. Rheological behavior of the nonsoluble but swellable CL-CMRS was similar to that of commercial superdisintegrants sodium starch glycolate (SSG), and cross-carmellose sodium (CCS). The swelling and water uptake of CL-CMRS were 5-7 and 6-25 times higher, respectively, than that of the native starch. Disintegration test of tablets containing 1 and 3% w/w of native and modified rice starches showed that M-KL1-5 and M-KL1-10 could be developed as tablet disintegrants.

Preparation and physicochemical properties of modified jackfruit starches

“…Washing was continued many times until free phosphate was not detected. Starch product was finally washed with methanol, oven-dried at 50 C for 24 h. The phosphate content was determined as described previously (Kittipongpatana, Chaitep, & Kittipongpatana, 2010).…”

“…The supernatant was dried to a constant weight at 120 C. The weights of the dried residue and of the sedimented paste were used to calculate the solubility percentage and the swelling power, respectively (Nwokocha & Williams, 2009). Water uptake of samples was carried out using a Nogami's apparatus as described by Kittipongpatana et al (2010).…”

“…Each heatingecooling cycle consisted of two days each of a cold storage at 8 C and a warm storage at 45 C. Paste clarity was determined by placing 2.5 mL of the paste in a cuvette and measured %T at 650 nm against a water blank. Apparent viscosity was measured using a Brookfield R/ S-CPS rheometer (Bob-and-Cup format) according to a method described by Kittipongpatana et al (2010). Viscosity was expressed in Pa s.…”

Impact of Thermal and Chemical Modifications on the Compression and Release Properties of Bambara Nut Starches in Directly Compressed Tablet Formulations

“…Carboxymethylated form of the starch was prepared using a method modified from Kittipongpatana et al The dried flakes of the modified starch were ground and screened through a number 120 mesh (125 µm) British standard sieve. The modified starch was weighed and stored in air tight containers.…”

Synthesis of Carboxymethyl Starch for increasing drilling mud quality in drilling oil and gas wells

“…Glyoxal refers to such substances, but being widely used as a cross-linking agent for starch and cellulose in pulp and paper industry, it is not enough studied. It might be suggested to get efficient conditions of carboxymethylation for modification of starch by cross-linking agents due to alkaline solution with рН = 7.5 -12 [9].…”