Oral Drug Delivery System Research Articles

Harnessing a Safe Novel Lipid Nanoparticle: Targeted Oral Delivery to Colonic Epithelial and Macrophage Cells in a Colitis Mouse Model

A novel lipid nanoparticle (nLNP), formulated with three essential lipids to mimic ginger-derived exosomal particles, shows strong potential for delivering IL-22 mRNA specifically to the colon, presenting a unique oral drug delivery system for inflammatory bowel disease (IBD). However, its cellular targets and uptake behavior in healthy versus diseased colons remain unclear. Understanding these aspects is crucial for fully elucidating its targeting effectiveness in inflamed colon tissue. This study investigates the nLNP’s cellular targets in healthy and diseased mouse colons. Flow cytometry compared nLNP uptake in healthy mice and a DSS-induced acute colitis model. The results revealed efficient internalization of nLNP by colonic epithelial cells in healthy and inflamed mice. In non-inflamed mice, the small number of colonic macrophages resulted in minimal uptake of nLNP by these cells. In inflamed mice, macrophages migrated to the damaged epithelium, where nLNP uptake was significantly increased, highlighting the nLNP’s ability to target both epithelial and macrophage cells during inflammation. Additionally, safety assessments showed that the nLNP neither altered in vitro kinase activities nor exhibited immunotoxicity or induced in vivo toxicity at the maximum tolerated oral dose. These findings underscore the nLNP’s safety and potential as a promising epithelial/macrophage-targeted drug delivery platform for oral ulcerative colitis (UC) treatment.

Non-invasive, continuous oral delivery of solid levodopa-carbidopa for management of Parkinson's disease.

When short plasma half-life drugs act only briefly, they require frequent or continuous administration. We report the engineering of a non-invasive oral drug delivery system for long-term, continuous administration of these drugs. Their non-invasive, long-term, continuous administration at daily doses exceeding 100 mg has, for many years, been considered an insurmountable challenge. We show that over 1200 mg/day of 4:1 levodopa-carbidopa (LD-CD) can be non-invasively and continuously extruded when formulated as a semisolid paste, loaded with 63%w/w of the solid drugs. The drug delivery system comprises a reusable orthodontic retainer with a co-molded pocket into which the patient inserts after each meal a new 1 mL propellant-driven, prefilled, disposable, drug delivery extruder. The paste is delivered to the lingual side of the teeth where it is mixed with saliva and swallowed. As reported elsewhere, a 15-day, 16 patient open label clinical trial of the drug delivery system continuously extruding LD-CD paste significantly reduces the variability of the plasma LD concentration and alleviates symptoms of advanced Parkinson's disease (PD) as compared to LD-CD tablets.

A Programmable Oral Nanomotor Microcapsule for the Treatment of Inflammatory Bowel Disease

AbstractGiven the unique anatomy and location of inflammatory bowel disease (IBD), oral pharmacological treatment is the mainstay for managing IBD because of its convenience and direct accessibility to the gastrointestinal tract. However, efficient delivery systems must be designed to navigate the harsh gastrointestinal environment during application. Here, an innovative oral drug delivery system was proposed using nanomotor (NM)‐loaded soluble microcapsules for treating IBD. MnO2‐Au‐mSiO2 NMs incorporate partially encapsulated MnO2 antennas that convert reactive oxygen species into oxygen, autonomously propelling the NMs. Astaxanthin (AST), known for its anti‐inflammatory properties, is loaded into the mesoporous silica (mSiO2) of NMs (AST@NMs). AST effectively reduces inflammation and shifts macrophages from a proinflammatory (M1) phenotype to an anti‐inflammatory (M2) phenotype. To protect the nanomotors from harsh digestive conditions and achieve intestinal‐responsive release, using photocurable 3D printing, we fabricated enteric‐coated oral microcapsules (MCs). Additionally, to prevent leakage of AST@NMs, a calcium alginate shell was cured in situ on the surface of the microcapsules (AST@NMs@MCs). In vitro and in vivo, AST@NMs@MCs effectively reduced inflammation, repaired the intestinal barrier, and modulated the gut microbiota. These findings underscore the protective effects of the microcapsules on AST@NM, highlighting their potential as a promising strategy for treating colitis.

Ferric ions crosslinked hyaluronic acid beads: potentials for drug delivery use

Introduction and purpose Despite the attractive properties of hyaluronic acid (HA), The preparation of HA beads is still challenging. This article reports the preparation of pH-sensitive gel HA beads. The ionic gelation method was used to prepare the HA gel beads using ferric ions. This cross-linking type is based on forming coordination bonds, which enhance the mechanical properties of the prepared beads. Methods The developed beads were characterized using Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). Scanning electron microscopy (SEM) examined the bead’s morphology. Furthermore, the potential of HA gel beads as an oral drug delivery system was investigated using metformin as a hydrophilic model drug. The entrapment efficiency and in vitro, release, and release kinetics were evaluated. The crosslinking density and HA concentration effect on drug release and bead swelling capacity under pH 1.2 and 7.4 were also investigated. Results The entrapment efficiency of metformin in HA beads was found to be 79.56 ± 3.89%. FTIR analysis indicated the ionic interaction between ferric ions and the carboxylic groups on the HA molecule. At the same time, there was no substantial interaction between metformin and the polymeric bead. Morphological evaluation and DSC analysis suggested the successful incorporation of metformin within the beads. The in vitro drug release evaluation showed pH-dependent extended release where the release kinetics followed the first-order mathematical model. Conclusions This study provides a value-added formulation with the potential for drug delivery use, which can be further investigated for biomedical applications.

Folic Acid - Based Hydrogels Co-assembled with Protocatechuic Acid for Enhanced Treatment of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) presents a significant therapeutic challenge due to the need for oral drug delivery systems that withstand acidic environment of stomach while effectively targeting intestinal inflammation. To address this issue, we created a novel hydrogel system based on a folic acid (FA)-dopamine (DA) conjugate, co-assembled with protocatechuic acid (PCA), to form F-DP hydrogels. These hydrogels demonstrated robust anti-gastric acid, mucosal adhesive, and injectable properties, enhancing their efficacy for targeted delivery. In DSS-induced colitis mouse models, treatment with F-DP hydrogels resulted in significant therapeutic improvements, including increased body weight, reduced disease activity index (DAI), and maintained colon length. Biochemical assays revealed that F-DP hydrogels significantly enhanced antioxidant enzyme activities (GSH and SOD) and reduced oxidative stress markers (NO and MDA). Histological assessments confirmed effective repair of the colonic mucosal barrier, restoration of tight junction protein ZO-1, and reduction of inflammatory lesions. Furthermore, immunofluorescence staining indicated that F-DP hydrogels facilitated macrophages polarization from the pro-inflammatory M1 phenotype to the anti-inflammatory M2 phenotype, thereby reducing inflammation and promoting tissue repair. Our study demonstrates that F-DP hydrogels show significant potential for improving IBD treatment through enhanced gastric resistance, intestinal adhesion, and synergistic anti-inflammatory effects, warranting further investigation for clinical applications.

Oral mucoadhesive drug delivery system: Formulation strategies and evaluation techniques

Mucoadhesive drug delivery systems (MDDS) represent an innovative method for administering drugs through oral routes such as the buccal, sublingual, and gingival areas. These systems leverage natural or synthetic polymers to ensure prolonged adherence to mucosal surfaces, enabling extended and controlled release of medication. Several factors influence the effectiveness of mucoadhesion, including the hydrophilicity of polymers, molecular weight, and environmental factors like pH and moisture levels. MDDS can take various forms, including tablets, films, patches, lozenges, and gels, each offering different drug release profiles such as immediate, sustained, or controlled. These systems enhance drug bioavailability by avoiding first-pass metabolism, making them particularly beneficial for medications with low oral bioavailability or those requiring targeted delivery. Although MDDS offer improved patient compliance and therapeutic effectiveness, they still face challenges like irritation, taste concerns, and the diluting effect of saliva, which can impact drug stability. Despite these challenges, MDDS hold significant promise for advancing drug delivery technologies across various medical applications. This review thoroughly examines the mechanisms, advantages, limitations, and future prospects of mucoadhesive drug delivery systems.

Recent Updates in Nanocrystal Technology: A Reference to Oral Drug Delivery System

Increasing the oral bioavailability of drugs that dissolve slowly may be possible with the use of nanocrystal technology. It is being employed for drug engineering and research after making rapid advancements in recent years. The manufacturing process for pharmaceuticals is significantly hampered by the low solubility and quick rate of dissolution of poorly soluble medications. When taken orally, medications that are poorly soluble often have low and inconsistent bioavailability, which could lead to therapeutic failure. Pure drug nanocrystals prepared via "bottom-up" or "topdown" procedu are able to significantly improve the way poorly soluble medications dissolve thanks to their enormous surface area, which in turn enhances oral absorption. Nanocrystal medications allow for the creation of various dosage formulations. The use of nanocrystal technology in pharmaceutical research, particularly for oral drug delivery systems, is the main focus of this review. First, a quick discussion on the characteristics of pharmaceutical nanocrystals and several nanocrystal technology preparation techniques is provided. The application of nanocrystal technology in pharmaceutical science is covered after a discussion of the creation of prolonged-release formulations. Next follows a brief overview of the scaling-up procedure, commercial nanocrystal drug products, and regulatory aspects of nanodrugs. This paper offers a thorough explanation of preparation techniques, their characterisation, and how they are used in oral drug delivery systems.

Construction and Evaluation of pH‐Responsive Nitrogen‐Containing Metal–Organic Frameworks as Oral Drug Carriers

ABSTRACTMetal–organic framework (MOF) is a porous material composed of metal ions/clusters and organic ligands. It has attracted much attention due to its high specific surface area, good biocompatibility, chemical modifiability, and diversity of components. Among many MOFs, zirconium‐based MOFs are particularly suitable for biological applications due to their optimal stability and low toxicity to hydrolysis. However, due to the weak coordination bonds between many metal clusters and organic ligands, most MOFs are prone to collapse in acidic environments, and the stability of MOFs as drug carriers cannot be guaranteed so that they cannot be widely used as oral drug carriers. This study synthesized the three MOFs using metal Zr ion clusters as the center and different nitrogen‐containing organic ligands, which are stable in gastric acid, namely, UiO‐66‐PDC, UiO‐66‐NH2, and UiO‐66‐NO2. The anionic drug loxoprofen (LOX) was loaded and characterized using scanning electron microscopy, infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, and x‐ray diffraction. The adsorption and release behaviors of LOX and the three MOFs were studied from the molecular point of view by computer simulation. A series of behaviors and mechanisms of pH‐responsive nitrogen‐containing MOFs as oral drug carriers were further explored through rat pharmacokinetic experiments, the everted gut sac experiments, and intestinal absorption mechanism experiments. The experimental results show that there is a strong electrostatic interaction between anionic drug LOX and UiO‐66‐PDC under simulated gastric acid environment, which prolongs the half‐life of the drug, proving that LOX@UiO‐66‐PDC is a promising new oral drug delivery system.

Design of self-emulsifying oral delivery systems for semaglutide: reverse micelles versus hydrophobic ion pairs.

It was the aim of this study to evaluate the potential of reverse micelles (RM) and hydrophobic ion pairs (HIP) for incorporation of semaglutide into self-emulsifying oral drug delivery systems. Reverse micelles loaded with semaglutide were formed with a cationic (ethyl lauroyl arginate, ELA) and an anionic surfactant (docusate, DOC), whereas HIP were formed between semaglutide and ELA. Maximum solubility of the peptide and the rate of dissolution was evaluated in various lipophilic phases (glycerol monocaprylocaprate:caprylic acid 1:4 (m/m), glycerol monolinoleate:caprylic acid 1:4 (m/m) and glycerol monocaprylocaprate:glycerol monolinoleate 1:4 (m/m)). Self-emulsifying drug delivery systems (SEDDS) loaded with RM and HIP were characterized regarding size distribution, zeta potential, cytocompatibility and Caco-2 permeability. Droplet sizes between 50 and 300nm with polydispersity index (PDI) around 0.3 and zeta potentials between - 45 mV (RMDOC) and 36 mV (RMELA) were obtained. RM provided an almost 2-fold higher lipophilicity of semaglutide than HIP resulting in a 4.2-fold higher payload of SEDDS compared to HIP. SEDDS containing RM or HIP showed high cytocompatibilities with a cell survival above 75% for concentrations up to 0.1% on Caco-2 cells and acceptable hemolytic activity. Permeation studies across Caco-2 monolayer revealed an at least 2-fold increase in permeability of semaglutide for the developed formulations.

Biodegradable polymeric nanocomposite containing phloretin for enhanced oral bioavailability and improved myocardial ischaemic recovery

Aim The study aimed to enhance phloretin’s oral absorption and systemic availability through nanoencapsulation within biodegradable polymers, improving its anti-oxidant and cardioprotective potential. Methods Phloretin-loaded polymeric nanocomposites were prepared using ionic gelation and optimised for yield, encapsulation, loading, particle size, PdI and zeta potential. The formulation was characterised by FTIR, XRD, FESEM and MS. In-vitro drug release, stability, pharmacokinetics, biodistribution, anti-oxidant capacity, haemolysis and both in-vitro and in-vivo assessments were conducted in an ischaemia-induced rat model. Results The average particle size, zeta potential, encapsulation and drug loading of the optimised nanoparticles were 105.8 ± 1.92 nm, −41.5 ± 1.10 mV, 92.36 ± 0.01% and 18.47 ± 0.38%, respectively. Nano-phloretin enhanced oral bioavailability, anti-oxidant capacity. In-vivo, it reduced myocardial infarct size by ∼46% versus ∼13% for free phloretin, showing significant cardiomyocyte protection and ROS suppression. Conclusion The study demonstrates polymer-based nanoparticles as effective oral drug delivery systems capable of enhancing both systemic bioavailability and therapeutic efficacy of the encapsulated drug.

Innovative Oral Nano/Gene Delivery System Based on Engineered Modified Saccharomyces cerevisiae for Colorectal Cancer Therapy.

The efficient delivery of RNA-based drugs to solid tumors remains a formidable obstacle. We aim to develop a safe and efficient oral drug delivery system compatible with RNA-based drugs that is urgently needed to overcome challenges such as enzymatic degradation and gastrointestinal barriers to facilitate effective treatment for treating colorectal cancer (CRC). To address these challenges, we utilized engineered modified Saccharomyces cerevisiae to evaluate the delivery efficacy of miR21-antagomir for treating CRC in preclinical mouse models, including adenomatosis polyposis coli mutant transgenic mice ApcMin/+ and in situ tumor-bearing mice. An orally deliverable gene delivery system, YS@NPs21, was designed. This gene delivery system demonstrated effectively suppressed tumor growth in both ApcMin/+ and in situ tumor-bearing mice models. This system exhibited tumor-targeting capability, effective inhibition of tumor growth, and low toxicity toward nontumor cells. Successful implementation of this innovative oral drug delivery system could offer a straightforward, safe, and RNA drug-compatible approach to CRC treatment, ultimately improving patient outcomes and reducing medical costs.

Biomolecular Condensates Based on Amino Acid for Enhancing Oral Bioavailability and Therapeutic Efficacy of Hydrophobic Drugs.

The oral administration of chemo- or immunotherapeutic drugs presents a compelling alternative for patients with malignant colorectal cancer, offering a convenient and patient-compliant "hospital-free" strategy. Unfortunately, the hydrophobic nature of many drug candidates, alongside the harsh conditions of the gastrointestinal tract, frequently results in suboptimal bioavailability and heightened systemic toxicity. To address these challenges, we harnessed the unique properties of biomolecular condensates, which form through a liquid-liquid phase separation mechanism, to develop a versatile platform for drug encapsulation and delivery. In this study, we introduce a reliable and effective amorphous oral drug delivery system based on biomolecular condensates derived from the amino acid derivative N-(benzyloxycarbonyl)-l-proline (ZP). These ZP condensates exhibit dynamic intermolecular interactions and possess unique physicochemical attributes such as fluidity and viscoelasticity. They significantly improve the solubility of hydrophobic drugs, ensuring enhanced stability and optimized pharmacokinetics under physiological and gastrointestinal conditions. By maintaining drugs in an amorphous state, we substantially increased drug bioavailability and markedly improved pharmacokinetics. Furthermore, the ZP condensates demonstrate potential as an integrated therapeutic platform capable of potentiating the synergies between chemotherapy and immunotherapy while concurrently reducing systemic toxicity. This has resulted in a significant enhancement of chemo-immunotherapy efficacy in the treatment of colorectal cancer, representing a notable advancement in drug delivery and oncology.

A Comprehensive Review of Challenges in Oral Drug Delivery Systems and Recent Advancements in Innovative Design Strategies.

The oral route of drug administration is often preferred by patients and healthcare providers due to its convenience, ease of use, non-invasiveness, and patient acceptance. However, traditional oral dosage forms have several limitations, including low bioavailability, limited drug loading capacity, and stability and storage issues, particularly with solutions and suspensions. Over the years, researchers have dedicated considerable effort to developing novel oral drug delivery systems to overcome these limitations. This review discusses various challenges associated with oral drug delivery systems, including biological, pharmaceutical, and physicochemical barriers. It also explores common delivery approaches, such as gastroretentive drug delivery, small intestine drug delivery, and colon-targeting drug delivery systems. Additionally, numerous strategies aimed at improving oral drug delivery efficiency are reviewed, including solid dispersion, absorption enhancers, lipidbased formulations, nanoparticles, polymer-based nanocarriers, liposomal formulations, microencapsulation, and micellar formulations. Furthermore, innovative approaches like orally disintegrating tablets (ODT), orally disintegrating films (ODF), layered tablets, micro particulates, self-nano emulsifying formulations (SNEF), and controlled release dosage forms are explored for their potential in enhancing oral drug delivery efficiency and promoting patients' compliance. Overall, this review highlights significant progress in addressing challenges in the pharmaceutical industry and clinical settings, offering novel approaches for the development of effective oral drug delivery systems.

Review about the Application of Biocompatible Materials in Oral Cavity Drug Delivery Systems

Review about the Application of Biocompatible Materials in Oral Cavity Drug Delivery Systems

Mesoporous polydopamine (MPDA)-based drug delivery system for oral chemo-photothermal combinational therapy of orthotopic colon cancer

Oral nano-drug delivery systems offering combination therapy have garnered significant interest in colon cancer treatment due to their precision in targeting tumors and minimizing peripheral tissue exposure. However, challenges such as the complex gastrointestinal environment and effective retention of nanoparticles in the colon have impeded further advancement. We developed a novel oral drug delivery system designed for localized treatment of colon cancer via chemotherapy and photothermal therapy (PTT). This system utilized mesoporous polydopamine (MPDA) as a photothermal carrier for doxorubicin hydrochloride (DOX), with surface modification using folic acid (FA) to enhance systemic tumor targeting. Additionally, to ensure gastrointestinal retention and precise colon localization, the nanoparticles were coated with an enteric-soluble material, ES100, resulting in the formulation MPDA-FA-DOX/ES100. This formulation exhibited high photothermal conversion efficiency, robust photothermal stability, and responsive drug release under near-infrared (NIR) laser stimulation. FA modification significantly enhanced the cellular uptake of nanoparticles by CT26 cells, promoting greater cytotoxic effects through combined chemotherapy and PTT. In vivo, MPDA-FA-DOX/ES100 demonstrated superior accumulation in colon tumor tissues and substantial photothermal effects, and notably, the CT/PTT group demonstrated significant tumor growth inhibition along with excellent biocompatibility. Collectively, these findings highlight the clinical potential of MPDA-FA-DOX/ES100 as an effective platform for localized and synergistic CT/PTT of colon cancer.

A Comprehensive Review of Xanthan Gum-Based Oral Drug Delivery Systems.

Xanthan gum (XG) is an exopolysaccharide synthesized by the aerobic fermentation of simple sugars using Xanthomonas bacteria. It comprises a cellulosic backbone with a trisaccharide side chain connected to alternative glucose residues in the main backbone through α (1→3) linkage. XG dissolves readily in cold and hot water to produce a viscous solution that behaves like a pseudoplastic fluid. It shows excellent resistance to enzymatic degradation and great stability throughout a broad temperature, pH, or salt concentration range. Additionally, XG is nontoxic, biocompatible, and biodegradable, making it a suitable carrier for drug delivery. Furthermore, the carboxylic functions of pyruvate and glucuronic acid offer a considerable opportunity for chemical modification to meet the desired criteria for a specific application. Therefore, XG or its derivatives in conjunction with other polymers have frequently been studied as matrices for tablets, nanoparticles, microparticles, and hydrogels. This review primarily focuses on the applications of XG in various oral delivery systems over the past decade, including sustained-release formulations, gastroretentive dosage forms, and colon-targeted drug delivery. Source, production methods, and physicochemical properties relevant to drug delivery applications of XG have also been discussed.

Oral Patch/Film for Drug Delivery-Current Status and Future Prospects.

In recent years, there has been extensive research into drug delivery systems aimed at enhancing drug utilization while minimizing drug toxicities. Among these systems, oral patches/films have garnered significant attention due to their convenience, noninvasive administration, ability to bypass hepatic first-pass metabolism, thereby enhancing drug bioavailability, and their potential to ensure good compliance, particularly among special patient populations. In this review, from the perspective of the anatomical characteristics of the oral cavity and the advantages and difficulties of oral drug delivery, we illustrate the design ideas, manufacturing techniques, research methodologies, and the essential attributes of an ideal oral patch/film. Furthermore, the applications of oral patches/films in both localized and systemic drug delivery were discussed. Finally, we offer insights into the future prospects of the oral patch/film, aiming to provide valuable reference for the advancement of oral localized drug delivery systems.

Advanced Oral Drug Delivery Systems for Combating and Preventing Paediatric Periodontal Disease

: The oral route is the most common route of administration of drugs. Over 90% of all the available marketed pharmaceutical products are oral formulations. Oral drugs are used in different courses of treatment including the prevention of tooth decay. Tooth decay is the permanent damage of the enamel which leads to the formation of cavities. It can be prevented with good oral hygiene and enough fluorides in the body. Fluorides can be administered both topically (toothpastes) and systemically (supplements). Fluoride supplements fall under oral drug delivery systems. They come in the form of tablets, lozenges, and liquids. However, challenges are faced when it comes to oral drug delivery in children. The development of paediatric drugs is a difficult undertaking since many pharmaceutically active compounds have low water solubility, instability, or an unpleasant taste. Children are unable to tolerate bitter or unpleasant- tasting formulations, as well as huge pills and capsules. Due to various biological, biochemical, and physical barriers faced by oral drug delivery systems, new approaches have been developed to address these challenges such as the application of nanotechnology in drug development. Jellies for oral administration on the other hand are a new approach for the delivery of drugs with bitter tastes as well as for age groups such as children and elders. They are clear, translucent, or non-greasy semisolid products that can be used both externally and internally. In-depth, aspects of these factors will be discussed in this review paper including oral dosage forms for paediatrics, tooth decay and its pathogenesis, preventive measures and setbacks of each measure as well as the future perspectives.

Colon-specific controlled release of oral liposomes for enhanced chemo-immunotherapy against colorectal cancer

A colon-specific drug delivery system has great potential for the oral administration of colorectal cancer. However, the uncontrollable in vivo fate of liposomes makes their effectiveness for colonic location, and intratumoral accumulation remains unsatisfactory. Here, an oral colon-specific drug delivery system (CBS-CS@Lipo/Oxp/MTZ) was constructed by covalently conjugating Clostridium butyricum spores (CBS) with drugs loaded chitosan (CS)-coated liposomes, where the model chemotherapy drug oxaliplatin (Oxp) and anti-anaerobic bacteria agent metronidazole (MTZ) were loaded. Following oral administration, CBS germinated into Clostridium butyricum (CB) and colonized in the colon. Combined with colonic specifically β-glucosidase responsive degrading of CS, dual colon-specific release of liposomes was achieved. And the accumulation of liposomes at the CRC site furtherly increased by 2.68-fold. Simultaneously, the released liposomes penetrated deep tumor tissue via the permeation enhancement effect of CS to kill localized intratumoral bacteria. Collaborating with blocking the translocation of intestinal pathogenic bacteria from lumen to tumor with the gut microbiota modulation of CB, the intratumoral pathogenic bacteria were eliminated fundamentally, blocking their recruitment to immunosuppressive cells. Furtherly, synchronized with lipopolysaccharide (LPS) released from MTZ-induced dead Fusobacterium nucleatum and the tumor-associated antigens produced by Oxp-caused immunogenic dead cells, they jointly enhanced tumor infiltration of CD8+ T cells and reactivated robust antitumor immunity.

HYDROPHILIC MATRIX TABLETS AS ORAL CONTROLLED DRUG DELIVERY SYSTEMS IN 20TH CENTURY: A REVIEW

Matrix systems are easy to formulate compared to other controlled release dosage forms. The manufacture of matrix tablets involves the direct compression of blend of drug, retardant material and additives to form a tablet in which drug is embedded in a matrix core of the retardant. Alternatively, retardant-drug blends may be granulated prior to compression. Of the three classes of retardant material used to formulate matrix tablets, polymers that form hydrophilic matrices are attracting the attention of pharmaceutical technologists. These polymers include Methyl cellulose (MC), Hydroxy ethyl cellulose (HEC), Hydroxy popyl methyl cellulose (HPMC), Sodium carboxy methyl cellulose (NaCMC), carbomers, chitosan, plant gums etc. The hydrophilic matrix-formers alone or in combination with other excipients form gels in situ on coming in contact with biological fluids which control the drug release. The present review gives a detailed account on the factors to be considered in the design of hydrophilic matrix systems, formulation of hydrophilic matrix tablets, in vitro and in vivo evaluation methods and advances in the design of hydrophilic matrix tablets. This review further focuses on the development of oral controlled drug delivery systems using hydrophilic matrix carriers in 20th century.