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PubMed2001

Bioavailability of cyclosporin A dispersed in sodium lauryl sulfate-dextrin based solid microspheres.

The purpose of this work was to develop a solid dispersion system containing cyclosporin A (CsA) in order to improve the bioavailability of poorly water-soluble CsA. Solid dispersion systems that are spherical in shape (CsA-microspheres) were prepared with varying ratios of CsA/sodium lauryl sulfate/dextrin using a spray-drying technique. The effects of sodium lauryl sulfate (SLS) and dextrin on the dissolution of CsA dispersed in SLS-dextrin based solid microspheres were investigated. The bioavailability of CsA-microspheres was compared with CsA powder alone and commercial Sandimmun in dogs. SLS significantly enhanced the dissolution of CsA from microspheres, while dextrin did not affect this. The CsA-microspheres at the CsA/SLS/dextrin ratio of 1/3/1, which gave the highest dissolution rate of CsA among the formula treated, was selected as an optimal formula for oral delivery. This formula gave significantly higher blood levels, area under the drug concentration-time curve (AUC) and maximum blood concentration of drug (Cmax) of CsA in dogs compared with the CsA powder alone. The AUC, Cmax and time to reach maximum blood concentration (Tmax) of CsA with CsA-microspheres was not significantly different from those after oral administration of Sandimmun, suggesting the similar bioavailability to Sandimmun in dogs. Our study demonstrates that the CsA-microspheres prepared with SLS and dextrin, with improved bioavailability of CsA, would be useful to deliver a poorly water-soluble CsA and could be applicable to other poorly water-soluble drugs.

Animals↗
PubMed1977

Intravenous infusion of a dextrin, Caloreen, in human subjects: metabolic studies.

1. Caloreen, a glucose-polymer dextrin infused into human volunteers, although producing a clear increase in total plasma carbohydrate did not produce a satisfactory increase in plasma glucose levels or serum insulin levels. 2. Urinary losses were high and although small fragments of the dextrin (suggesting metabolic breakdown of the dextrin) were demonstrated in the urine, no suppression of plasma free fatty acid, glucagon or immediate increase in the respiratory quotient were noted, suggesting that the metabolism is too slow to make it useful for parenteral nutrition in its present form. 3. A dextrin with fewer branch-links might be more suitable.

Adult↗
PubMed1999

Anti-Kaposi's sarcoma and antiangiogenic activities of sulfated dextrins.

Delivery of the sulfated polysaccharide dextrin 2-sulfate by the intraperitoneal route to the lymphatic circulation resulted in a clinically significant improvement in Kaposi's sarcoma in three patients. Our in vitro studies show that although sulfated dextrins do not interfere with the growth of isolated human umbilical vein endothelial cells, they do inhibit the morphological differentiation of endothelial cells into tubes as well as reduce new vessel formation in a placental angiogenesis assay. The antiangiogenic effect of dextrin 6-sulfate is greater than that of dextrin 2-sulfate and is independent of their anti-human immunodeficiency virus type 1 activities.

Anti-HIV Agents↗
PubMed2000

Affinity capillary electrophoretic studies of complexation between dextrin oligomers and polyiodides.

Capillary electrophoresis (CE) has been applied to the study of complexation between dextrins and polyiodides. A baseline separation of fluorescently labeled dextrin oligomers has provided a unique platform for the observation of a contribution of single oligomers to the complexation process that could previously be measured only in bulk. The complex formation was easily recognized through comparison of peak migration times and peak shapes in the presence and absence of polyiodides. The degree of polymerization (DP) number was found crucial in the binding process, but the I2/I- ratio in a solution also appeared to determine the nature of complexation. The effects of buffer pH and ionic strength upon complexation were also briefly investigated. Diodearray spectra in the visible wavelength range confirmed the differential complexation of unlabeled maltodextrins with different DP values after a CE iodine affinity separation. 13C-nuclear magnetic resonance (NMR) spectral data on differently sized dextrin fractions were found to be in good agreement with the results from CE measurements.

Dextrins↗
PubMed2004

Characterization of the trehalosyl dextrin-forming enzyme from the thermophilic archaeon Sulfolobus solfataricus ATCC 35092.

The trehalosyl dextrin-forming enzyme (TDFE) mainly catalyzes an intramolecular transglycosyl reaction to form trehalosyl dextrins from dextrins by converting the alpha-1,4-glucosidic linkage at the reducing end to an alpha-1,1-glucosidic linkage. In this study, the treY gene encoding TDFE was PCR cloned from the genomic DNA of Sulfolobus solfataricus ATCC 35092 to an expression vector with a T7 lac promoter and then expressed in Escherichia coli. The recombinant TDFE was purified sequentially by using heat treatment, ultrafiltration, and gel filtration. The obtained recombinant TDFE showed an apparent optimal pH of 5 and an optimal temperature of 75 degrees C. The enzyme was stable in a pH range of 4.5-11, and the activity remained unchanged after a 2-h incubation at 80 degrees C. The transglycosylation activity of TDFE was higher when using maltoheptaose as substrate than maltooligosaccharides with a low degree of polymerization (DP). However, the hydrolysis activity of TDFE became stronger when low DP maltooligosaccharides, such as maltotriose, were used as substrate. The ratios of hydrolysis activity to transglycosylation activity were in the range of 0.2-14% and increased when the DP of substrate decreased. The recombinant TDFE was found to exhibit different substrate specificity, such as its preferred substrates for the transglycosylation reaction and the ratio of hydrolysis to transglycosylation of the enzyme reacting with maltotriose, when compared with other natural or recombinant TDFEs from Sulfolobus.

Amino Acid Sequence↗
PubMed2006

Novel hydrogel obtained by chitosan and dextrin-VA co-polymerization.

A novel hydrogel was obtained by reticulation of chitosan with dextrin enzymatically linked to vinyl acrylate (dextrin-VA), without cross-linking agents. The hydrogel had a solid-like behaviour with G' (storage modulus) >> G'' (loss modulus). Glucose diffusion coefficients of 3.9 x 10(-6) +/- 1.3 x 10(-6) cm(2)/s and 2.9 x 10(-6) +/- 0.5 x 10(-6) cm(2)/s were obtained for different substitution degrees of the dextrin-VA (20% and 70% respectively). SEM observation revealed a porous structure, with pores ranging from 50 microm to 150 microm.

Acrylates↗
PubMed1984

The effects of duodenal glucose and dextrin infusion on adipose tissue metabolism in sheep.

Three groups of 3 sheep were penned individually and provided with pelleted dried grass. In addition two of the groups received either dextrin or glucose via duodenal cannulae. The rate of in vitro lipogenesis, from acetate of glucose, in subcutaneous adipose tissue was significantly increased in the carbohydrate-infused sheep. The increase in lipogenesis in response to glucose infusion was much greater than that to dextrin infusion. The changes in lipogenesis induced by dextrin or glucose infusion were reflected in the specific activities of the various lipogenic enzymes examined. These results are discussed in relation to the capacity of the sheep small intestine to hydrolyse alpha-linked glucose polymer.

Acetates↗
PubMed2003

Acid hydrolysis of native and annealed starches and branch-structure of their Naegeli dextrins.

Eight commercial starches, including common corn, waxy corn, wheat, tapioca, potato, Hylon V, Hylon VII, and mung bean starch, were annealed by a multiple-step process, and their gelatinization characteristics were determined. Annealed starches had higher gelatinization temperatures, reduced gelatinization ranges, and increased gelatinization enthalpies than their native starches. The annealed starches with the highest gelatinization enthalpies were subjected to acid hydrolysis with 15.3% H2SO4, and Naegeli dextrins were prepared after 10 days' hydrolysis. Annealing increased the acid susceptibility of native starches in the first (rapid) and the second (slow) phases with potato starch showing the greatest and high amylose starches showing the least changes. Starches with a larger shift in onset gelatinization temperature also displayed a greater percent hydrolysis. The increase in susceptibility to acid hydrolysis was proposed to result from defective and porous structures that resulted after annealing. Although annealing perfected the crystalline structure, it also produced void space, which led to porous structures and possible starch granule defects. The molecular size distribution and chain length distribution of Naegeli dextrins of annealed and native starches were analyzed. The reorganization of the starch molecule during annealing occurred mainly within the crystalline lamellae. Imperfect double helices in the crystalline lamellae improved after annealing, and the branch linkages at the imperfect double helices became protected by the improved crystalline structure. Therefore, more long chains were observed in the Naegeli dextrins of annealed starches than in native starches.

Amylopectin↗
PubMed2005

Fluids containing a highly branched cyclic dextrin influence the gastric emptying rate.

The rates of gastric emptying for highly branched cyclic dextrin (HBCD) and other carbohydrate (CHO) solutions were examined using ultrasonograph techniques. Ten healthy volunteers ingested water, physiological saline, or solutions containing various CHO, such as HBCD, glucose, maltose, sucrose, and commercially available dextrin. After a subject drank one of the solutions, the relaxed cross-sectional area of the pylorus antrum was measured at rest by real-time ultrasonography. The time required for gastric emptying was correlated with the relaxed cross-sectional area of the pylorus antrum. Among all of the solutions tested, physiological saline was transferred fastest from the stomach to the small intestine. For solutions of the same CHO, 5 % solution was transferred faster than 10 % solution. For CHO solutions other than HBCD, a low osmotic pressure was associated with rapid transfer from the stomach. The gastric emptying time (GET) of HBCD solution increased with an increase in its concentration. A shorter GET was observed for the CHO solutions at 59 to 160 mOsm regardless of their concentration. A sports drink based on 10 % HBCD adjusted to 150 mOsm by the addition of various minerals, vitamins, and organic acids was evacuated significantly (p < 0.05) faster than a 10 % HBCD solution or a sports drink based on 10 % commercially available dextrin (DE16), which has a higher osmotic pressure (269 mOsm). Our results suggest that a shorter GET could be achieved with CHO solutions with osmotic pressures of 59 - 160 mOsm. Therefore, a sports drink based on 10 % HBCD adjusted to 150 mOsm by the addition of minerals, vitamins, and organic acids could supply adequate quantities of CHO, fluid, and minerals simultaneously in a short time, without increasing GET.

Administration, Oral↗
PubMed2004

Physicochemical characterization of solid dispersions of indomethacin with PEG 6000, Myrj 52, lactose, sorbitol, dextrin, and Eudragit E100.

The purpose of this study was to prepare and characterize solid dispersions of indomethacin with polyethylene glycol (PEG) 6000, Myrj 52, Eudragit E100, and different carbohydrates such as lactose, mannitol, sorbitol, and dextrin. Indomethacin is a class II substance according to the Biopharmaceutics Classification System. It is a poorly water soluble antirheumatic agent. The goal was to investigate whether the solid dispersion can improve the dissolution properties of indomethacin. The solid dispersions were prepared by three different methods depending on the type of carrier. The evaluation of the properties of the dispersions was performed using solubility measurements, dissolution studies, Fourier-transform infrared spectroscopy, and x-ray powder diffractometery. The results indicate that lactose, mannitol, sorbitol, and especially Myrj 52 are suitable carriers to enhance the in vitro dissolution rate of indomethacin at pH 7.2. Eudragit E100, Myrj 52, and mannitol increase the dissolution properties at pH 1.2. The data from the x-ray diffraction showed that the drug was still detectable in its solid state in all solid dispersions except solid dispersions with dextrin and high amounts of mannitol. However, the results from infrared spectroscopy together with those from x-ray diffraction showed well-defined drug-carrier interactions for dextrin coevaporates.

Acrylates↗
PubMed1975

Structures of multi-branched dextrins produced by saccharifyiing alpha-amylase from starch.

From the digest of beta-limit dextrin (prepared from glutinous rice starch) with saccharifying alpha-amylase of Bacillus subtilis [EC 3.2.1.1] (BSA), two extensibely branched dextrins consisting of nine (No. 6, Fig. 1) and ten (No 7, Fig.1) glucose units were isolated by paper chromatography. Structural analysis using various enzymes revealed that No. 6 and No. 7 were both mixtures of four triply branched dextrins. They had structures which were built up with 63-alpha-glucosylmaltotriose and/or 62-alpha-glucosylmaltose as a linking unit. However, the branching configuration and the minimum alpha-1, 4-glucosidic linkages existing between two branches followed one of the three structures shown below: (see article).

Amylases↗
PubMed2005

A randomized controlled safety and acceptability trial of dextrin sulphate vaginal microbicide gel in sexually active women in Uganda.

OBJECTIVE: To assess the safety of dextrin sulphate (DS) gel compared to placebo gel in terms of local and systemic adverse events, and to determine the acceptability of dextrin sulphate gel. DESIGN: A 4-week randomized trial of DS intra-vaginal gel, partially blinded, with placebo and observation control arms. Participants were randomized to use DS gel twice daily, placebo gel twice daily, DS gel pre-sex, or into an observation only arm. METHODS: Sexually active women were recruited from post natal and HIV clinics at Nsambya Hospital, Kampala, Uganda. Screening, enrollment and follow-up visits took place every 1 or 2 weeks over an 8-week period and consisted of questionnaire interviews, colposcopy examinations, sexually transmitted infection screen and routine laboratory testing. RESULTS: Out of a total of 172 women screened, 109 were randomized to use DS gel twice daily (65 women), placebo gel twice daily (15 women), DS gel pre-sex (nine women) or into an observation only arm (20 women). Two individuals had abnormal colposcopy findings in the DS twice daily gel use arm. Vaginal bleeding was reported as frequently by participants in the active gel arm as by participants in the placebo and observation only arms. No clinically significant difference was observed between arms in terms of vaginal flora, Candida, haemoglobin, white cell count, platelets, thrombin time, activated partial thromboplastin time, creatinine and aspartate aminotransferase results after 4 weeks of gel use. DS gel appeared to be acceptable to over 95% of the users. CONCLUSIONS: Results show a satisfactory safety and acceptability profile of dextrin sulphate gel.

Administration, Intravaginal↗
PubMed1975

Elimination of precipitates in oil red O fat stain by adding dextrin.

Addition of dextrin in the final 60% isopropanol of the Lillie-Ashburn super-saturated oil red O isopropanol technic moderately intensified the stain and decreased our required staining interval. Precipitates were decreased and the diluted solution remained usable into the second week. A saturated 60% isopropanol oil red O solution contained 33 mg/100 ml. Without dextrin the fresh supersaturated solution contains 40 mg, after 3 days 25 mg. With dextrin the fresh solution contained 130 mg dye, the 10-day-old one 100 mg/100 ml.

1-Propanol↗
PubMed2000

Dextrin as excipient in pharmaceutical preparations.

The addition of commercial dextrins to aqueous solvents in thin layer chromatography on cellulose increases the Rf values of azodyes such as methyl orange. The increase is less than with cyclodextrins but shows that dextrins also form supramolecular complexes. This should be considered when dextrins are used as "inert" excipients in pharmacy.

Azo Compounds↗
PubMed1992

Evaluation of malto-dextrin/glycine oral rehydration solution.

The efficacy and safety of malto-dextrin/glycine-based oral rehydration solution (ORS) when compared with the glucose-based oral rehydration solution (WHO) was evaluated in a randomized double-blind clinical trial. Thirty-one subjects and 31 controls were studied. The mean values of the ORS intake, stool output, duration of diarrhoea, urine output, weight gain and serum electrolytes were comparable in both the study and the control groups (p > 0.05). It was found that the malto-dextrin/glycine ORS offered no therapeutic advantage over the standard glucose ORS (WHO). In view of the accidental preponderance of children of significantly lower nutritional status among the control group (p < 0.05), it is likely that the efficacy of malto-dextrin/glycine ORS might actually be less than that of the glucose ORS.

Diarrhea, Infantile↗
PubMed1996

Dextrin sulfopropyl ether: a novel anionic chiral buffer additive for enantiomer separation by electrokinetic chromatography.

Dextrin 10 sulfopropyl ether (DSPE) was prepared and characterized by matrix-assisted laser-desorption ionization-mass spectrometry (MALDI-MS) using a recently developed matrix. The anionic compound was used as a novel chiral buffer additive for enantiomer separation by capillary electrophoresis, thereby changing into the elektrokinetic chromatography (EKC) mode. DSPE was systematically evaluated as a chiral selector and was compared to the respective nonderivatized maltodextrin. DSPE showed an increased separation power for cationic racemic solutes. Although not quite as versatile and powerful as cyclodextrins, the inexpensive dextrin 10 and its derivative DSPE showed remarkable enantioselectivity in some cases.

Anions↗
PubMed2005

Dietary supplementation of different doses of NUTRIOSE FB, a fermentable dextrin, alters the activity of faecal enzymes in healthy men.

BACKGROUND: It is well documented that fermentation of carbohydrates that escape digestion exert several effects supposed to be beneficial for (colonic) health, including an increase in stool volume, a shorter intestinal transit time, production of short chain fatty acids and a decrease of colonic pH (Kritchevsky 1988). NUTRIOSE FB is a dextrin that is not completely hydrolysed and absorbed in the small intestine, due to many alpha-1.6 linkages and the presence of non-digestible glucoside linkages (e. g. alpha-1.2 and alpha-1.3). To be beneficial for 'colonic' health effective NUTRIOSE FB must reach the cecum in some form. AIM OF THE STUDY: To estimate how much non digested NUTRIOSE FB is fermented and to determine the fibre-like effect of the wheat dextrin NUTRIOSE((R))FB by analysing enzymatic activity in faeces. METHODS: In a randomized, double-blind,multiple dose, placebo-controlled, combined cross-over and parallel trial, 20 healthy men (age 31.7 +/- 9.1 yrs; BMI 24.5 +/- 2.9 kg.m(-2) received different treatments. One group of ten subjects consumed on top of their diet 10, 30 and 60 g daily of NUTRIOSE FB or maltodextrin (placebo). The other group of 10 subjects consumed 15, 45 and 80 g daily. Each dose was consumed for 7 days. On the last two days of each of the 7-day period, faeces were collected in which the enzymatic activity and NUTRIOSE FB residue were analysed. RESULTS: As expected, the faecal residue of NUTRIOSE FB non-linearly increased with the dose of NUTRIOSE FB to approximately 13% of 80 g/d. Compared with the placebo, 30, 45, 60 and 80 g/d of NUTRIOSE FB increased the concentration of alpha-glucosidase significantly. All daily doses of NUTRIOSE FB (10 g/d to 80 g/d) led to significant changes in concentration of beta-glucosidase. CONCLUSIONS: The small amount of the residue of NUTRIOSE FB in the faeces suggests that approximately 87% or more of NUTRIOSE FB is digested or fermented in the gastrointestinal tract. Fermentation of NUTRIOSE FB led to an increased faecal concentration of alpha- and beta-glucosidase.

Adult↗