pectins and Colonic-Diseases

Pectin-derived matrices are now being examined and tested for controlled drug delivery. Pectin is intact in the upper gastrointestinal tract and degraded by colonic microflora. The composition of this microflora remains relatively consistent across a diverse human population. Thus, pectin-derived drug carriers provide promising potential for colon-specific drug delivery. This paper reviews recent developments in pectin-derived formulations. Subjects reviewed include gelation of pectin, calcium cross-linked pectinate, composites of pectin and other polymers, technologies to fabricate pectin into useful drug delivery vehicles, and methods to evaluate release kinetics of incorporated drugs. This article discusses advantages, limitations, and possible future developments in pectin-based formulations with particular emphasis on the field of colon-specific drug delivery.

Topics: Administration, Oral; Animals; Calcium; Cations; Cellulose; Colon; Colonic Diseases; Dose-Response Relationship, Drug; Drug Carriers; Drug Delivery Systems; Humans; Models, Chemical; Pectins; Polymers

Epidemiologic reports have linked how intakes of dietary fiber with numerous diseases and abnormal conditions. They range from diverticulitis to coronary thrombosis, from simple constipation to possible carcinoma of the colon. The supposed etiology underlying these and other conditions is discussed in terms of the properties of cellulose, lignin, and hemicelluloses, including pectin, which collectively make up dietary fiber. Other major organic components of plant foods, apart from fiber, protein, fat, sugars and starches, are considered briefly. The desirability of improved nomenclature is emphasized. Urgently needed is a thorough study of the biochemistry and metabolism, using experimental animals, of dietary fiber in foods. Only when this is done can there be a good understanding of the mechanisms involved and a realization of the possibilities suggested by the epidemiologic studies.

Topics: Cardiovascular Diseases; Cathartics; Cellulose; Colon; Colonic Diseases; Dental Caries; Diabetes Mellitus; Dietary Fiber; Digestion; Food Analysis; Gastrointestinal Diseases; Humans; Lignin; Male; Obesity; Pectins; Polysaccharides; Terminology as Topic

Calcium-pectinate (Ca-pectinate) beads have shown immense potential as colon-specific drug carrier. However, Ca-pectinate itself is unable to prevent its swelling/degradation in the upper gastro-intestinal (GI) conditions. Hence, polyethyleneimine (PEI) was added in the cross-linking solution to strengthen the Ca-pectinate network. Resveratrol was used as a model drug due to its promising therapeutic activity towards several colonic diseases. Beads were prepared by varying cross-linking solution pH and other formulation variables. The effects of these formulation variables were investigated on the bead's characteristics. Furthermore, surface morphology, drug-polymer interaction, stability, and in vivo pharmacokinetic study of the optimized formulation were performed. The optimized PEI-modified beads prevented drug release in the upper GI conditions, while released the drug in simulated colonic fluid. Furthermore, in vivo pharmacokinetics studies in rats demonstrated delayed appearance of drug in blood after oral administration. The optimized Ca-pectinate beads demonstrated both in vitro and in vivo colon-specific drug release.

Topics: Animals; Colon; Colonic Diseases; Drug Delivery Systems; Drug Evaluation, Preclinical; Male; Microspheres; Pectins; Polyethyleneimine; Rats; Rats, Sprague-Dawley

The present work was aimed at designing microsponge based colon specific drug delivery system containing paracetamol. Eudragit S-100 based microsponges containing drug in varying amounts were prepared using quasi-emulsion solvent diffusion method. The microsponges were prepared by optimizing various process parameters. DSC and FTIR studies indicated compatibility of the drug in various formulations. Shape and surface morphology of the microsponges were examined using scanning electron microscopy. The formulations were subjected to in vitro release studies and the results were evaluated kinetically and statistically. The in vitro release data showed a bi-phasic pattern with an initial burst effect. In the first hour drug release from microsponges was found to be between 18-30%. The cumulative percent release at the end of 12(th) hour was noted to be between 74-98%. The release kinetics showed that the data followed Higuchi model and the main mechanism of drug release was diffusion. The colon specific tablets were prepared by compressing the microsponges followed by coating with pectin: hydroxypropylmethyl cellulose (HPMC) mixture. In vitro release studies exhibited that compression coated colon specific tablet formulations started releasing the drug at 6(th) hour corresponding to the arrival time at proximal colon. The study presents a new approach for colon specific drug delivery.

Topics: Acetaminophen; Analgesics, Non-Narcotic; Calorimetry, Differential Scanning; Colon, Ascending; Colonic Diseases; Delayed-Action Preparations; Diffusion; Drug Compounding; Drug Delivery Systems; Hydrogen-Ion Concentration; Hypromellose Derivatives; Kinetics; Methylcellulose; Particle Size; Pectins; Pharmaceutic Aids; Polymethacrylic Acids; Solubility; Spectroscopy, Fourier Transform Infrared; Surface Properties; Tablets

The potential of the generic kaopectate (Upjohn) as a negative rectal contrast agent in MR imaging was investigated in the assessment of colorectal disease. 45 MR examinations in patients with colorectal disease (colorectal carcinoma 25 patients, inflammatory disease 12 patients, miscellaneous disorders of the colon 8 patients) were evaluated. All examinations were performed with T1 and T2 weighted SE sequences after rectal application of kaopectate. Gd-DTPA enhanced T1 SE sequences were obtained as well. Kaopectate revealed a signal void of the lumen of the large intestine in T1 and T2 weighted SE sequences. Intravenous administration of Gd-DTPA enabled good differentiation of contrast-enhanced malignant or inflammatory tissue and the low signal lumen of the bowels. No side effects were noted.

Topics: Adult; Aged; Aged, 80 and over; Bentonite; Colonic Diseases; Colorectal Neoplasms; Contrast Media; Drug Combinations; Drug Evaluation; Female; Gadolinium; Gadolinium DTPA; Humans; Kaolin; Magnetic Resonance Imaging; Male; Middle Aged; Models, Structural; Organometallic Compounds; Pectins; Pentetic Acid; Rectal Diseases; Rectum; Time Factors

The relationship between dietary fiber and intestinal circular muscle cell size was investigated in rats by feeding defined diets supplemented with four different sources of fiber. In the first study, a 20% wheat bran supplement was fed to 10 rats for nine weeks. This resulted in larger muscle cell size, with a 22.5% increase in the proximal (P less than 0.02) and 77.9% increase in the distal colon (P less than 0.01) when compared with a control group of 10 rats fed a fiber-free diet. In the second study, which lasted four weeks, a control group of 10 rats was fed a fiber-free diet, while similar sized experimental groups were fed the same basal diet plus either 20% oat bran, 10% pectin, or 10% guar. Muscle cell size was decreased by 20.6% in the proximal jejunum of the oat bran- and pectin-fed groups (P less than 0.05) and by 43% in the proximal colon of the oat bran-fed group, when compared with the controls (P less than 0.05). These results show that the effects of high fiber diets on intestinal muscle cell size depend on the type of fiber consumed.

Topics: Animals; Autoradiography; Colonic Diseases; Dietary Fiber; Digestive System; DNA; Galactans; Male; Mannans; Muscle Development; Muscle, Smooth; Pectins; Plant Gums; Rats; Thymidine; Tritium

Topics: Animals; Colonic Diseases; Diarrhea; Male; Pectins; Rabbits; Sulfates; Ulcer