pH-sensitive and mucoadhesive microspheres for duodenum-specific drug delivery system
Yue-Hua Liu1, Xi Zhu, Dan Zhou
1Key Laboratory of Drug Targeting and Drug Delivery, Ministry of Education, West China School of Pharmacy, Sichuan University, Chengdu, PR China.
Drug Development and Industrial Pharmacy
|January 15, 2011
Summary
This study developed a novel drug delivery system for duodenal ulcers using thiolated chitosan microspheres coated with HPMCAM. The system demonstrated excellent mucoadhesion and targeted drug release in the duodenum.
Area of Science:
- Pharmaceutical Sciences
- Biomaterials Science
- Drug Delivery Systems
Background:
- Developing targeted drug delivery systems for duodenal applications remains a challenge.
- Mucoadhesive properties are crucial for prolonged drug contact time in the duodenum.
- Existing systems lack specificity for duodenal drug release.
Purpose of the Study:
- To engineer a novel duodenum-specific drug delivery system.
- To utilize thiolated chitosan and hydroxypropyl methylcellulose acetate maleate (HPMCAM) for targeted delivery.
- To evaluate the system's efficacy for duodenal ulcer treatment using berberine hydrochloride as a model drug.
Main Methods:
- Synthesis of thiolated chitosan and hydroxypropyl methylcellulose acetate maleate (HPMCAM).
- Preparation of mucoadhesive microspheres using thiolated chitosan.
- Coating of microspheres with HPMCAM for pH-dependent release.
- In vitro mucoadhesion, morphological, and drug release studies in simulated gastric and duodenal fluids.
Main Results:
- Thiolated chitosan immobilization achieved 268.21 ± 18 μmol/g.
- Thiolated chitosan microspheres (TCM) exhibited superior mucoadhesion compared to non-thiolated counterparts.
- HPMCAM coating remained intact in simulated gastric fluid (SGF) for 2 hours and dissolved in simulated pathological duodenal fluid (SPDF; pH 3.3).
- Minimal drug release (4.75%) occurred in SGF, with ~90% released within 6 hours in SPDF.
Conclusions:
- The developed HPMCAM-coated TCM system provides effective duodenum-specific drug delivery.
- The system exhibits controlled release characteristics, releasing the drug primarily in the duodenal environment.
- This novel system holds significant potential for treating duodenal ulcers with improved therapeutic outcomes.
Related Concept Videos
01:11Oral Drug Delivery Systems: Delayed-Release Systems
Delayed-release drug delivery systems are specialized pharmaceutical formulations designed to postpone the release of active compounds until the drug reaches a specific region of the gastrointestinal (GI) tract, typically the intestine. These systems are essential for drugs that may cause gastric irritation, are unstable in acidic environments, or need to exert therapeutic effects locally in the intestinal or colonic regions.The core feature of delayed-release systems is the use of enteric...
01:27Drug Delivery Systems: Different Types
Conventional oral drug products, termed immediate-release (IR) formulations, are engineered to promptly release their active pharmaceutical ingredient (API) upon ingestion, typically in tablets or capsules. This rapid release often results in swift drug absorption and consequent pharmacodynamic effects, although the timing and intensity can vary depending on the drug's properties. Prodrugs within these formulations require metabolic conversion to activate their pharmacodynamic effects,...
01:24Site-Targeted Drug Delivery Systems: Polymeric Carriers
Polymeric carriers enhance targeted drug delivery by increasing efficacy while minimizing off-target effects. These carriers comprise a biodegradable polymeric backbone integrated with functional elements that enable targeting, improve physicochemical properties, and regulate drug release.Targeting MechanismsThe targeting ability of polymeric carriers is mediated by a homing device, which is a molecular recognition component designed to selectively bind to specific tissues or cells. Monoclonal...
01:26Oral Drug Delivery Systems: Continuous-Release Systems
Continuous-release drug delivery systems offer a strategic approach to maintaining therapeutic drug levels over extended periods following oral administration. By modulating the release rate of active pharmaceutical ingredients, these systems minimize fluctuations in plasma concentrations, which enhances clinical efficacy and reduces the need for frequent dosing. Such characteristics make them particularly advantageous in managing chronic diseases where patient adherence and stable drug...
01:24Modified-Release Drug Delivery Systems: Site-Targeted
Site-targeted drug delivery systems enhance therapeutic efficacy while minimizing systemic toxicity and treatment costs. Unlike conventional methods, these systems ensure precise drug delivery, improving bioavailability and reducing side effects. Targeted drug delivery is classified into three levels. First-order targeting directs drugs to the capillary beds of specific organs or tissues. Second-order targets specific cell types, such as tumor cells, using receptor-mediated interactions.
01:22Modified-Release Drug Delivery Systems: Rate-Programmed I
Rate-programmed drug delivery systems (DDS) are designed to release drugs at specific, controlled rates to maintain consistent therapeutic levels. These systems are categorized based on their release mechanisms, including dissolution-controlled DDS, diffusion-controlled DDS, and combined dissolution-diffusion-controlled DDS.In dissolution-controlled DDS, the release rate depends on the slow dissolution of the drug itself or the surrounding matrix. Drugs with inherently slow dissolution rates,...