Modified-Release Delivery Systems
Larry L. Augsburger, Stephen W. Hoag in Pharmaceutical Dosage Forms, 2017
The platform is highly flexible and lends itself to a variety of delivery system designs that could be complementary with different biopharmaceutical properties of the drug in relation to physiological constraints imposed by the GI tract. Ideally, the extended-release delivery system should provide release rate and duration of release that would match the necessary amount of drug in the blood for a specific duration of therapy. The modified-release capsule delivery platform permits for constant release (zero-order), variable release (pulsatile), delayed release, or extended drug release and absorption over a prolonged period after ingestion. Capsules can be enteric coated, or coated pellets/granules that resist releasing in the acidic environment of the stomach can be encapsulated. Enteric coating delays release of medicament until the capsule or its contents have passed through the stomach. Potential modified-release capsule delivery systems and sophisticated release rates and patterns that can be realized from manufacturing of different controlled-release capsule delivery designs are shown in Figures 12.6 and 12.7a and b.
Drug Absorption and Bioavailability
Kate McCombe, Lara Wijayasiri, Paul Hatton, David Bogod in The Primary FRCA Structured Oral Examination Study Guide 2, 2017
Most drugs are taken orally and pass from the mouth into the aqueous and acidic environment of the stomach. Here they may dissolve and cross into the cells lining the stomach. Dissolution and absorption can be altered by the manufacturers in several ways: Particle size: The larger the particle size (molecular weight) of the drug, the more slowly it will dissolve.Compounds used: Different compounds dissolve at different rates. Modified-release or slow-release drugs can improve the drug profile, minimising peaks and troughs in plasma concentration. Patient compliance improves with less frequent dosing.Coating the tablet: Enteric coating does not dissolve in acid conditions and therefore the drug will pass to the basic intestine before dissolving.
Prescribing for minor illness
Gina Johnson, Ian Hill-Smith, Chirag Bakhai in The Minor Illness Manual, 2018
Modified-release tablets are designed to dissolve slowly to give a prolonged effect or reduced side effects. Gastro-resistant or enteric coating is a way of protecting a drug from damage by gastric acid. The coating resists acid but dissolves in the more alkaline small bowel, the main site of absorption of almost all oral drugs. Note that the coating is most often required to protect the drug, and only for a few medications is it helpful in protecting the patient's stomach. Gastric side effects are usually due to the overall effect of a drug after it has been absorbed, so the route by which it is given is immaterial. A non-steroidal anti-inflammatory drug can cause a gastric bleed from its systemic action, whether it is given orally, rectally or by injection.
Study on formulation and preparation technology of the composite cellulose-based enteric capsule shells
Published in Drug Development and Industrial Pharmacy, 2022
Liping Liu, Huaiqin Luo, Yingying Yang, Jinqin Huang, Chang Liu, Qiaoling Ding, Huien Zhang
Hard capsule dosage forms are widely used to encapsulate powders, granules, pellets, nonaqueous liquids, and semisolids because they offer better protection against oxygen, moisture and light until the drug is released [1]. Capsule shell is an essential part of capsule dosage forms. Enteric coating is desirable for the administration of medications that are irritating to the stomach or unstable in gastric acid environment [2]. Enteric coating can delay the release of the drug from the dosage form until it reaches the small intestine. Other types of coatings are also applied to deliver the drug at an intended site of the gastrointestinal tract or to release the drug over an extended time [3]. There are three kinds of methods for the preparation of drug enteric capsules: ① The drug particles or pellets are coated with enteric-coated materials firstly, and then filled into capsule shell [4,5]; ② The enteric-coated materials solution is sprayed on the surface of the capsule shell filled with drugs [6]. ③ The drug is directly filled into the enteric capsule shell [7–9]. Comparing the three methods, the first and second methods have the potential impact of the diffusion and residue of coating solvent on the filling drug, and the potential danger of the volatilization of organic coating solvent on the production workshop. The third method effectively avoids the above problems. Therefore, it is necessary to develop enteric capsule shell.
Preparation and evaluation in vitro and in vivo of pristinamycin enteric-coated granules based on albumin nanoparticles
Published in Drug Development and Industrial Pharmacy, 2023
Wanxin Shan, Fang Peng, Qi Shen, Jun Zhang
In trial studies, pristinamycin has been found to be a poor water-soluble medication [28–30], although its solubility can be enhanced by encapsulating it with albumin [31]. Above all, albumin is a nonexclusive transporter protein that forms complexes with insoluble or foreign compounds and functions as a “ferry” for such molecules in the circulation [20,32]. Eudragit L100-55 is commonly utilized as a targeting agent for oral colonic drug administration (tablet coating, tablet matrix, microspheres, and NPs) [33,34]. It also has mucosal adhesion qualities and decreased moisture permeability [34,35], ensuring that the encapsulated particles are kept at the site of action. As such, we selected Eudragit L100-55 as the primary coating material via which the NPs possessed the enteric action. It is based on the enteric coating’s qualities, which can successfully protect the medicine from being damaged by gastric acid while also maximizing the drug’s reach to the intestine. The enteric coating is then dissolved in the gastrointestinal tract. Because of its mucosal adhesion property, it can be kept for an extended period of time in the intestine, extending the drug’s therapeutic duration in the intestinal system. Following that, the granules breakdown in the intestine, and albumin NPs increase the drug’s solubility and boost absorption. We contend that the medicine penetrates the intestinal cells in the form of albumin NPs via endocytosis [36,37], maximizing absorption and increasing the needed concentration in the body. For these reasons, we created the formulation, which serves as the general design concept.
Diagnosis and management of pancreatic exocrine insufficiency (PEI) in primary care: consensus guidance of a Canadian expert panel
Published in Current Medical Research and Opinion, 2018
P. Durie, J.-D. Baillargeon, S. Bouchard, F. Donnellan, S. Zepeda-Gomez, C. Teshima
PERT provides biologically active porcine enzymes to replace endogenous enzyme activity within the lumen of the small bowel. Most currently available enzyme preparations are packaged as capsules, which may contain either powdered enzymes or microspheres, i.e. biodegradable polymer-based microparticles that allow controlled drug release35. An enteric coating is used on most products to prevent inactivation by gastric acid, allowing the enzymes to remain active as they enter the duodenum. Conversely, products without enteric coating should be taken at a higher dose, generally with a proton pump inhibitor (PPI) to minimize gastric acid inactivation36. PCPs should be aware that uncoated enzymes are sometimes used specifically for pain relief associated with CP37,38 and that dosing in this application is distinct from that for PEI. Table 4 lists the formulations of pancreatic enzyme supplements available to Canadian prescribers.
Related Knowledge Centers
- Anthelmintic
- Capsule
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- Polymer
- Small Intestine
- Stomach
- Medication
- Targeted Drug Delivery
- Tablet
- Dosage Form