Chitosan-clay nanocomposite as a drug delivery system of ibuprofen

Chitosan/montmorillonite nanocomposite films were prepared by the solvent evaporation method to immobilize the drug ibuprofen (IBU) and delay its release in a medium that simulates the environment of the gastrointestinal tract. The effects of montmorillonite, at different mass proportions (10, 20, and 50%), on the morphological and physical properties of the films were studied. The samples were characterized by X-ray diffraction (XRD), Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), degree of swelling, drug encapsulation, and drug release efficiency. According to the XRD it was evidenced that the incorporation of montmorillonite to chitosan led to the formation of nanocomposites of ordered morphology. The infrared spectra confirmed the good interaction between montmorillonite and chitosan by the formation of nanocomposites. This fact, which favored the imprisonment of the IBU, reduced the diffusion coefficient in the studied systems. The micrographs comproved the formation of dense and uniform films. The controlled release profile, especially for the nanocomposite with 10% clay mass, showed a slow drug release rate. The incorporation of montmorillonite at different proportions produced different morphologies, with good encapsulation efficiency and an adequate profile for the controlled release of the drug.

Recent Trends in Assessment of Cellulose Derivatives in Designing Novel and Nanoparticulate-Based Drug Delivery Systems for Improvement of Oral Health

Natural polymers are revolutionizing current pharmaceutical dosage forms design as excipient and gained huge importance because of significant influence in formulation development and drug delivery. Oral health refers to the health of the teeth, gums, and the entire oral-facial system that allows us to smile, speak, and chew. Since years, biopolymers stand out due to their biocompatibility, biodegradability, low toxicity, and stability. Polysaccharides such as cellulose and their derivatives possess properties like novel mechanical robustness and hydrophilicity that can be easily fabricated into controlled-release dosage forms. Cellulose attracts the dosage design attention because of constant drug release rate from the precursor nanoparticles. This review discusses the origin, extraction, preparation of cellulose derivatives and their use in formulation development of nanoparticles having multidisciplinary applications as pharmaceutical excipient and in drug delivery, as bacterial and plant cellulose have great potential for application in the biomedical area, including dentistry, protein and peptide delivery, colorectal cancer treatment, and in 3D printable dosage forms.

A Rapid Dual-Responsive Releasing Nano-Carrier by Decomposing the Copolymer and Reversing the Core Dissolution

The accumulation of nanotechnology-based drugs has been realized in various ways. However, the concentration of drugs encapsulated by nanomaterials is not equal to the concentration of effective drugs; often, the drugs become effective only when they are released from the nanomaterials as free drugs. This means only when the drugs are rapidly released after the accumulated drug-encapsulating nanomaterials can they truly achieve the purpose of increasing the concentration of drugs in the tumor. Therefore, we herein report a dual-response nano-carrier of glutathione and acid to achieve the rapid release of encapsulated drug and increase the effective drug concentration in the tumor. The nano-carrier was constructed using a dual-responsive amphiphilic copolymer, composed of polyethylene glycol and hydrophobic acetylated dextran and connected by a disulfide bond. In the tumor microenvironment, disulfide bonds could be biodegraded by glutathione that is overexpressed in the tumor, exposing the core of nano-carrier composed of acetylated dextran. Then the acidic environment would induce the deacetylation of acetylated dextran into water-soluble dextran. In this way, the nano-carrier will degrade quickly, realizing the purpose of rapid drug release. The results showed that the drug release rate of dual-responsive nano-carrier was much higher than that of glutathione or acid-responsive nano-carrier alone. Furthermore, both in vitro and in vivo experiments confirmed that dual-responsive nano-carrier possessed more efficient anti-tumor effects. Therefore, we believe that dual-responsive nano-carriers have better clinical application prospects.

Hot Melt Coating: Development and Optimization of Controlled Release Formulation and Process of Oxcarbazepine

Hot-melt coating process (HMCP) is being developed to formulate lipid based oral controlled release formulation system for anti-epileptic drug Oxcarbazepine. Pellets containing Active ingredient in the core portion were prepared by extrusion spheronization process with use of appropriate filler and binder. These core pellets were then coated using hot-melt coating technology with different levels of solid lipid material and a hydrophilic component. Formulation and Process parameters were optimized to achieve targeted drug release profile and other target product profile with particular focus on HMCP. Quality by design (QbD) with DOE approach was used for designing and development of the formulation, by putting risk assessment (FMEA, Fish-bone diagram), screening (by Plackett Burman), and optimization (by CCC) studies. Appropriate ‘design space’ was proposed based on the optimization studies. The results demonstrated that the level of Low melting coating component and a hydrophilic component influenced the drug release rate from the formulation, and the rate of release could be optimized by varying the amount of these components in the formulation. Processing parameters like Temperature of the coating solution and atomization air, Atomization air pressure and Spray rate also affects the drug release rate and other parameters like coating efficiency and mean particle size. For optimized formulation, dissolution data model fitting was also carried out which adequately fits to Higuchi model suggesting that the drug release occurred predominantly by diffusion.

FORMULATION AND EVALUATION OF DRUG RELEASE PROFILE OF HYDROPHILIC POLYMER BASED INDOMETHACIN PROLONG RELEASE MATRIX TABLETS

An oral modied release dosage forms have always been more effective therapeutic alternative to conventional dosage forms. The present invention is directed to a modied release pharmaceutical composition of indomethacin by using hydrophilic release retardant polymers like HPMC K15M, Na CMC alone or in combination. Matrix embedded prolong release tablet formulations of Indomethacin were prepared by wet granulation technique and evaluated for tablet properties such as the thickness, hardness, friability, weight variation, drug content, drug release kinetics and in vitro release studies. The inuence of drug polymer ratio on drug release was studied by dissolution test. The FTIR studies showed no interactions among drug and polymers. The tablets formulation (F7 and F8) containing combined polymers of HPMC K15M and Na CMC resulted in slower drug release rate form the matrix. So, it can be concluded that Indomethacin prolong release tablets using HPMC K15M and Na CMC as the retardant has successfully extended the release of indomethacin from its formulations. The mixing of two cellulose polymers, ionic and non-ionic, for the formulation of hydrophilic matrices, resulted in a valuable decrease in drug release rate. All the formulations showed KorsmeyerPeppa’s model as a best t.

Preparation of Epidermal Growth Factor-Modified Targeted Doxorubicin Nanoliposomes and Therapy of Liver Cancer

The objective of this study was to prepare doxorubicin-loaded EGF modified PEG-nanoparticles and evaluate its targeting capability and therapeutic effects with EGFR-expressing hepatocellular carcinoma cells. The morphology, particle size distribution, and doxorubicin content of the nanoparticles were measured, and the drug loading and encapsulation efficiency were calculated. The doxorubicin nanoparticles prepared were regular circular, with good dispersibility, no adhesion, and the average particle size was (136.7±9.3) nm. The average encapsulation efficiency was (76.67±8.63)%, the average drug loading was (3.86±0.55)%; the drug release rate of doxorubicin was 100% for 12 h, and the doxorubicin nanometer was loaded. The drug release rate of the granules was 52.9% at 24 h and 81.2% at 144 h. The inhibition rate of the proliferation of hepatocarcinoma cells by the doxorubicin-containing nanoparticles was slower than that of doxorubicin, and the IC50 of the two cells was 1.844 and 0.345 μg/mL, respectively. At the same time, apoptosis and cycle analysis showed that the doxorubicin nanoparticles could significantly inhibit the cell cycle of hepatoma cells and promote the apoptosis of hepatoma cells. This study successfully produced nanoparticles loaded with doxorubicin targeting EGFR, which has a good sustained release effect, and its antitumor effect is stronger than free doxorubicin.

Preparation and Drug Release Behavior of Nifedipine-Loaded Poly(lactic acid)/Polyethylene Glycol Microcapsules

Nifedipine (NF)-loaded poly(lactic acid) (PLA) and PLA/polyethylene glycol (PLA/PEG) microcapsules are synthesized using a high-speed agitator and a syringe pump with an oil-in-water emulsion-solvent evaporation technique to evaluate the effect of PLA/PEG ratio on morphology and drug release behavior of the capsules. Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimeter (DSC), and X-ray diffraction (XRD) results indicate that PEG reacts successfully with PLA due to the ether bond between PEG and PLA. The drug release rate of PLA and PLA/PEG capsules increases dramatically from 0 to 5 min and then reaches a plateau within 15 to 20 min. Due to the high specific surface area, the amount of NF released is raised by reducing the PLA concentration from 5 wt% to 2 wt%. Unlike PLA capsules, the drug release rate of PLA/PEG capsules increases due to the size effect by varying the PLA/PEG ratio from 10/0 to 6/4. Larger PLA/PEG capsules are attributed to higher amounts of encapsulated NF. The capsules show no evidence of cytotoxicity, suggesting that the PLA and PLA/PEG drug carriers are clinically safe.

Modelling and Simulation of the Drug Release from a Solid Dosage Form in the Human Ascending Colon: The Influence of Different Motility Patterns and Fluid Viscosities

For colonic drug delivery, the ascending part of the colon is the most favourable site as it offers the most suitable environmental conditions for drug dissolution. Commonly, the performance of a drug formulation is assessed using standardised dissolution apparatus, which does not replicate the hydrodynamics and shear stress evoked by wall motion in the colon. In this work, computer simulations are used to analyse and understand the influence of different biorelevant motility patterns on the disintegration/drug release of a solid dosage form (tablet) under different fluid conditions (viscosities) to mimic the ascending colonic environment. Furthermore, the ability of the motility pattern to distribute the drug in the ascending colon luminal environment is analysed to provide data for a spatiotemporal concentration profile. The motility patterns used are derived from in vivo data representing different motility patterns in the human ascending colon. The applied motility patterns show considerable differences in the drug release rate from the tablet, as well as in the ability to distribute the drug along the colon. The drug dissolution/disintegration process from a solid dosage form is primarily influenced by the hydrodynamic and shear stress it experiences, i.e., a combination of motility pattern and fluid viscosity. Reduced fluid motion leads to a more pronounced influence of diffusion in the tablet dissolution process. The motility pattern that provoked frequent single shear stress peaks seemed to be more effective in achieving a higher drug release rate. The ability to simulate drug release profiles under biorelevant colonic environmental conditions provides valuable feedback to better understand the drug formulation and how this can be optimised to ensure that the drug is present in the desired concentration within the ascending colon.

Synthesis of a PVA drug delivery system for controlled release of a Tramadol–Dexketoprofen combination

The local administration of analgesic combinations by means of degradable polymeric drug delivery systems is an alternative for the management of postoperative pain. We formulated a Tramadol–Dexketoprofen combination (TDC) loaded in poly(vinyl alcohol) (PVA) film. Films were prepared by the solvent casting method using three different molecular weights of PVA and crosslinking those films with citric acid, with the objective of controlling the drug release rate, which was evaluated by UV–vis spectrometry. Non-crosslinked PVA films were also evaluated in the experiments. Differential scanning calorimetry (DSC) analysis of samples corroborated the crosslinking of PVA by the citric acid. Blank and loaded PVA films were tested in vitro for its impact on blood coagulation prothrombin time (PT) and partial thromboplastin time (PTT). The swelling capacity was also evaluated. Crosslinked PVA films of higher-molecular weight showed a prolonged release rate compared with that of the lower-molecular-weight films tested. Non-crosslinked PVA films released 11–14% of TDC. Crosslinked PVA films released 80% of the TDC loaded (p < 0.05). This suggests that crosslinking films can modify the drug release rate. The blank and loaded PVA films induced PT and PTT in the normal range. The results showed that the polymeric films evaluated here have the appropriate properties to allow films to be placed directly on surgical wounds and have the capacity for controlled drug release to promote local analgesia for the control of postoperative pain.

Hierarchical Core–Shell Fe3O4@mSiO2@Chitosan Nanoparticles for pH-Responsive Drug Delivery

Hierarchical nanoparticles are of great interest because they possess unique physicochemical properties and multiple functionalities, providing a wealth of possibilities for various applications. In this work, we have developed a well-designed method to prepare hierarchical magnetic nanoparticles Fe3O4@mSiO2@CS by integrating a solvothermal method for synthesizing the Fe3O4 core, a dualtemplating micelle system for preparing a layer of mesoporous silica (mSiO2) shell, and a silane coupling method via γ-glycidoxypropyltrimethoxysilane for binding a chitosan (CS) layer on the silica surface. The porous hierarchical nanoparticles were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), dynamic light scattering nanoparticle size analyzer, and specific surface area and pore size analyzer. The loading capacity and the release behavior of the as-prepared nanoparticles for doxorubicin hydrochloride were studied, and it was found that the drug release rate was faster at pH 6.0 than at pH 7.4, revealing the pH-responsive property of the nanoparticles.