Improvement of anti-prion efficacy with stearoxy conjugation of hydroxypropyl methylcellulose in prion-infected mice.

Prion diseases are fatal transmissible neurodegenerative disorders. Among known anti-prions, hydroxypropyl methylcellulose compounds (HPMCs) are unique in their chemical structure and action. They have several excellent anti-prion properties but the effectiveness depends on the prion-infected mouse model. In the present study, we investigated the effects of stearoxy-modified HPMCs on prion-infected cells and mice. Stearoxy modification improved the anti-prion efficacy of HPMCs in prion-infected cells and significantly prolonged the incubation period in a lower HPMC-responding mouse model. However, stearoxy modification showed no improvement over nonmodified HPMCs in an HPMC-responding mouse model. These results offer a new line of inquiry for use with prion-infected mice that do not respond well to HPMCs.

Microbiological and Physicochemical Evaluation of Hydroxypropyl Methylcellulose (HPMC) and Propolis Film Coatings for Cheese Preservation.

Dairy products are highly susceptible to contamination from microorganisms. This study aimed to evaluate the efficacy of hydroxypropyl methylcellulose (HPMC) and propolis film as protective coatings for cheese. For this, microbiological analyses were carried out over the cheese' ripening period, focusing on total mesophilic bacteria, yeasts and moulds, lactic acid bacteria, total coliforms, Escherichia coli, and Enterobacteriaceae. Physicochemical parameters (pH, water activity, colour, phenolic compounds content) were also evaluated. The statistical analysis (conducted using ANOVA and PERMANOVA) showed a significant interaction term between the HPMC film and propolis (factor 1) and storage days (factor 2) with regard to the dependent variables: microbiological and physicochemical parameters. A high level of microbial contamination was identified at the baseline. However, the propolis films were able to reduce the microbial count. Physicochemical parameters also varied with storage time, with no significant differences found for propolis-containing films. Overall, the addition of propolis to the film influenced the cheeses' colour and the quantification of phenolic compounds. Regarding phenolic compounds, their loss was verified during storage, and was more pronounced in films with a higher percentage of propolis. The study also showed that, of the three groups of phenolic compounds (hydroxybenzoic acids, hydroxycinnamic acids, and flavonoids), hydroxycinnamic acids showed the most significant losses. Overall, this study reveals the potential of using HPMC/propolis films as a coating for cheese in terms of microbiological control and the preservation of physicochemical properties.

Fingerprinting of hydroxy propyl methyl cellulose by comprehensive two-dimensional liquid chromatography-mass spectrometry of monomers resulting from acid hydrolysis.

Hydroxypropyl methyl cellulose (HPMC) is a type of cellulose derivative with properties that render it useful in e.g. food, cosmetics, and pharmaceutical industry. The substitution degree and composition of the ß-glucose subunits of HPMC affect its physical and functional properties, but HPMC characterization is challenging due to its high structural heterogeneity, including many isomers. In this study, comprehensive two-dimensional liquid chromatography-mass spectrometry was used to examine substituted glucose monomers originating from complete acid hydrolysis of HPMC. Resolution between the different monomers was achieved using a C18 and cyano column in the first and second LC dimension, respectively. The data analysis process was structured to obtain fingerprints of the monomers of interest. The results revealed that isomers of the respective monomers could be selectively separated based on the position of substituents. The examination of two industrial HPMC products revealed differences in overall monomer composition. While both products contained monomers with a similar degree of substitution, they exhibited distinct regioselectivity.

Novel self-setting cements based on tricalcium silicate/(ß-tricalcium phosphate/monocalcium phosphate anhydrous)/hydroxypropyl methylcellulose: From hydration mechanism to biological evaluations.

Despite the clinical success of tricalcium silicate (TCS)-based materials in endodontics, the inferior handling characteristic, poor anti-washout property and slow setting kinetics hindered their wider applications. To solve these problems, an injectable fast-setting TCS/ß-tricalcium phosphate/monocalcium phosphate anhydrous (ß-TCP/MCPA) cement was developed for the first time by incorporation of hydroxypropyl methylcellulose (HPMC) and ß-TCP/MCPA. The physical-chemical characterization (setting time, anti-washout property, injectability, compressive strength, apatite mineralization and sealing property) of TCS/(ß-TCP/MCPA) were conducted. Its hydration mechanism was also investigated. Furthermore, the cytocompatibility and osteogenic/odontogenic differentiation of stem cells isolated from human exfoliated deciduous teeth (SHED) treated with TCS/ß-TCP/MCPA were studied. The results showed that HPMC could provide TCS with good anti-washout ability and injectability but slow hydration process. However, ß-TCP/MCPA effectively enhanced anti-washout characteristics and reduced setting time due to faster hydration kinetics. TCS/(ß-TCP/MCPA) obtained around 90 % of injection rate and high compressive strength whereas excessive additions of ß-TCP/MCPA compromised its injectability and compressive strength. TCS/(ß-TCP/MCPA) can induce apatite deposition and form a tight marginal sealing at the dentin-cement interface. Additionally, TCS/(ß-TCP/MCPA) showed good biocompatibility and promoted osteo/odontogenic differentiation of SHED. In general, our results indicated that TCS/(ß-TCP/MCPA) may be particularly promising as an injectable bioactive cements for endodontic treatment.

Active whey protein/hydroxypropyl methylcellulose edible films incorporated with cinnamaldehyde: Characterization, release kinetics and application to Mongolian cheese preservation.

Edible films with modulated release of antimicrobial agents are important for food preservation. Herein, antimicrobial edible films were prepared using whey protein (WP) and hydroxypropyl methylcellulose (HM) as polymer matrix materials and cinnamaldehyde (CIN) as antimicrobial agent. The mass ratios of WP and HM were 100/0, 75/25, 50/50, 25/75 and 0/100. The release kinetics of CIN through the film was studied, applying the Fickian model, power law and Weibull model. The films were also characterized by physical and structural characteristics, and antibacterial activity. In comparison to other films, the CIN-loaded film with a WP/HM ratio of 50/50 had better moisture resistance, water vapor barrier properties and mechanical properties. High correlation factors were obtained by fitting the CIN release data with the power law (R2 > 0.96) and Weibull model (R2 > 0.97). The diffusion mechanism of CIN was pseudo-Fickian. The diffusion coefficients (D1 and D2) had a positive linear relationship with the HM ratio, suggesting that a high HM ratio was beneficial to the CIN release. Finally, the WH50-C film was successfully used to preserve Mongolian cheese. This research provides a new perspective on the design of active packaging film with sustained-release characteristics.

Facile superhydrophobic modification on HPMC film using polydimethylsiloxane and starch granule coatings.

The excessive water sensitivity of hydroxypropyl methylcellulose (HPMC) films prevent them from being used extensively. In order to overcome this limitation, superhydrophobic HPMC films were meticulously crafted through the utilization of a composite of polydimethylsiloxane (PDMS) and ball-milled rice starch, corn starch, or potato starch (RS/CS/PS) for the coating process. Initially possessing hydrophilic properties, the HPMC Film (CA = 49.3 ± 1.8°) underwent a transformative hydrophobic conversion upon the application of PDMS, resulting in a static contact angle measuring up to 103.4 ± 2.0°. Notably, the synergistic combination of PDMS-coated HPMC with ball-milled starch demonstrated exceptional superhydrophobic attributes. Particularly, the treated HPMC-based film, specifically the HP-CS-2 h film, showcased an impressive contact angle of 170.5° alongside a minimal sliding angle of 5.2°. The impact of diverse starch types and the ball milling treatment on the PDMS/starch coatings and HPMC film was thoroughly examined using scanning electron microscopy (SEM), wide-angle X-ray diffraction (WAXS), and particle size analysis. These studies demonstrated that the low surface energy and roughness required for the creation of superhydrophobic HPMC-based films were imparted by the hierarchical structure formed by the application of PDMS/ball-milled starch. CHEMICAL COMPOUNDS STUDIED IN THIS ARTICLE: Polydimethylsiloxane (PubChem CID: 24764); Hydroxypropyl methylcellulose (PubChem CID: 671); Ethyl acetate (PubChem CID: 8857).

Structural homeostasis and controlled release for anthocyanin in oral film via sulfated polysaccharides complexation.

Oral film is a novel functional carrier, which can provide a new pathway for the efficient absorption of anthocyanin. However, anthocyanin homeostasis in oral film is a prerequisite for achieving efficient absorption and utilization of anthocyanin. Herein, three sulfated polysaccharides, including chondroitin sulfate (CS), fucoidin (FU) and λ-carrageenan (λ-CG), were complexed with blueberry anthocyanin (BA) to prepare oral film formulations using hydroxypropyl methylcellulose (HPMC) as a film-forming matrix. The addition of three sulfated polysaccharides improved the stability of BA in content and color, which were associated with interactions between BA and polysaccharides. The BA retention rate of CS-BA/HPMC system increased 5.5-fold after 8 d of light-accelerated storage compared with the control group, showing the best homeostasis effect. CS and λ-CG enhanced the elongation at break and prolonged disintegration time of oral films. The addition of FU made the oral film denser and smoother, and had the highest BA release (75.72 %) in the simulated oral cavity system. In addition, the oral films of three sulfated polysaccharides complexed with BA showed superior antioxidant capacity. The present study provides new insights into the application of anthocyanin in film formulation carriers.

An investigation into the effects of ink formulations of semi-solid extrusion 3D printing on the performance of printed solid dosage forms.

Semi-solid extrusion (SSE) 3D printing has recently attracted increased attention for its pharmaceutical application as a potential method for small-batch manufacturing of personalised solid dosage forms. It has the advantage of allowing ambient temperature printing, which is especially beneficial for the 3D printing of thermosensitive drugs. In this study, the effects of polymeric compositions (single hydroxypropyl methylcellulose (HPMC) system and binary HPMC + polyvinylpyrrolidone (PVP) system), disintegrant (silicon oxide (SiO2)), and active pharmaceutical ingredients (tranexamic acid (TXA) and paracetamol (PAC)) on the printability of semisolid inks and the qualities of SSE printed drug-loaded tablets were investigated. Printability is defined by the suitability of the material for the process in terms of its physical properties during extrusions and post-extrusion, including rheology, solidification time, avoiding slumping, etc. The rheological properties of the inks were investigated as a function of polymeric compositions and drug concentrations and further correlated with the printability of the inks. The SSE 3D printed tablets were subjected to a series of physicochemical properties characterisations and in vitro drug release performance evaluations. The results indicated that an addition of SiO2 would improve 3D printing shape fidelity (e.g., pore area and porosity) by altering the ink rheology. The pores of HPMC + PVP + 5PAC prints completely disappeared after 12 hours of drying (pore area = 0 mm2). An addition of SiO2 significantly improved the pore area of the prints which are 3.5 ± 0.1 mm2. It was noted that the drug release profile of PAC significantly increased (p < 0.05) when additive SiO2 was incorporated in the formulation. This could be due to a significantly higher porosity of HPMC + PVP + SiO2 + PAC (70.3 ± 0.2%) compared to HPMC + PVP + PAC (47.6 ± 2.1%). It was also likely that SiO2 acted as a disintegrant speeding up the drug release process. Besides, the incorporation of APIs with different aqueous solubilities, as well as levels of interaction with the polymeric system showed significant impacts on the structural fidelity and subsequently the drug release performance of 3D printed tablets.

Development of Sustained Release System Based on High Water-Absorbable Gel Formation Using Croscarmellose Sodium, Alkaline Excipients and HPMC (ACSH SR System); Novel Application of Croscarmellose Sodium as a Gel Former.

PURPOSE: Croscarmellose sodium, generally used as a superdisintegrant in pharmaceutical formulations, is hydrolyzed to form the gel structure under basic pH conditions. Utilizing this property of croscarmellose sodium, we developed a novel sustained release (SR) system. METHODS: Immediate release (IR) and SR tablets containing croscarmellose sodium, alkaline excipients and/or hydroxypropyl methylcellulose (HPMC) were prepared and examined for wet strength and in vitro drug release behavior. In vivo oral drug absorption was evaluated for IR tablets, HPMC tablets and our novel SR tablets in fasted Beagle dogs. RESULTS: To form the gel structure even under the physiological condition, alkaline excipients were added into the formulation containing croscarmellose sodium. Furthermore, HPMC was used to make the gel structure strong enough against mechanical destructive forces. The novel alkalized croscarmellose sodium-HPMC (ACSH) SR tablet, consisting of croscarmellose sodium, alkaline excipients, and HPMC, successfully sustained the release of acetaminophen, ibuprofen, or nicardipine hydrochloride, compared with the IR tablets. The ACSH SR system provided a better release of acetaminophen than the HPMC tablet without croscarmellose sodium in the release study using a small volume of liquid, suggesting that substantial release and subsequent absorption would be expected in the distal intestinal segments after oral dosing. The in vivo oral absorption study revealed that the ACSH SR system successfully suppressed and prolonged the plasma concentrations of acetaminophen. CONCLUSION: This novel ACSH SR system prepared with croscarmellose sodium, alkaline excipients, and HPMC, would be a promising SR formulation for enabling substantial drug absorption in the distal intestinal segments.

Biopolymer based film loaded with Cholecalciferol: A novel technique to enhance nutritional supplement absorbance.

In terms of delivery systems for active compounds, orally disintegrating films are a great option. The initial stage in creating an oral disintegrating film is selecting a film-forming polymer. The basic polymers combination Microcrystalline Cellulose (MCC), which is co-processed with Carboxymethylcellulose Sodium (CMC) and hydroxypropylmethyl cellulose were used to create an oral disintegrating film that contains cholecalciferol (Vitamin D3), a fat-soluble vitamin that aids in the body's absorption of calcium and phosphorus. The goal of the current inquiry was to develop orally disintegrating films of vitamin D3 to improve patient comfort and compliance for pediatric or elderly patients due to its simplicity of administration. Films containing drugs and made of the appropriate plasticizer and chosen polymers demonstrated outstanding film forming and folding endurance. The dissolution test showed that Vitamin D3 has a rapid disintegration property, with the majority of it dissolving in the medium (pH 6.8) in less than two minutes after being inserted. To verify that the films were successfully formed, a variety of procedures including HPLC, FT-IR and microscopic studies were employed. When kept at 40oC with humidity of 75%, the film showed good stability for at least three months.

Study on Improving the Performance of Traditional Medicine Extracts with High Drug Loading Based on Co-spray Drying Technology.

The purpose of this study is to develop modified particles with different structures to improve the flowability and compactibility of Liuwei Dihuang (LWDH) powder using co-spray drying technology, and to investigate the preparation mechanism of modified particles and their modified direct compaction (DC) properties. Moreover, tablets with high drug loading contents were also prepared. Particles were designed using polyvinylpyrrolidone (PVP K30) and hydroxypropyl methylcellulose (HPMC E3) as shell materials, and sodium bicarbonate (NaHCO3) and ammonium bicarbonate (NH4HCO3) as pore-forming agents. The porous particles (Ps), core-shell particles (CPs), and porous core-shell particles (PCPs) were prepared by co-spray drying technology. The key DC properties and texture properties of all the particles were measured and compared. The properties of co-spray drying liquid were also determined and analyzed. According to the results, Ps showed the least improvement in DC properties, followed by CPs, and PCPs showed a significant improvement. The modifier, because of its low surface tension, was wrapped in the outer layer to form a shell, and the pore-forming agent was thermally decomposed to produce pores, forming core-shell, porous, and porous core-shell composite structures. The smooth surface of the shell structure enhances fluidity, while the porous structure allows for greater compaction space, thereby improving DC properties during the compaction process.

Hydroxypropyl Methylcellulose Orodispersible Film Containing Desloratadine for Geriatric Use: Formulation and Evaluation.

BACKGROUND: Oral strip is very similar to thin strip of postage stamp in shape, size and thickness. The strip is designed to be placed on the tongue or any oral mucosal tissue which immediately gets wet and hydrated after being in contact with the saliva. Desloratadine is one of the better- known second-generation antihistamines that has been studied for being effective in relieving the allergic nasal and skin symptoms. OBJECTIVE: The aim of this study is to develop desloratadine orodispersible film (ODF) with fast disintegration time and suitable mechanical strength to treat allergic symptoms in geriatric patients in order to increase compliance and convenience. METHODS: Solvent casting method using hydroxypropyl methylcellulose (HPMC) as the film forming polymer was applied. Polyethylene glycol 400 (PEG 400) and glycerol (Gly) were used as the plasticizers and citric acid (CA) was used as saliva stimulating agent. The resultant films were evaluated for disintegration time, folding endurance, surface pH, weight variation, thickness, surface morphology using scanning electron microscopy, drug content, content uniformity, moisture loss, moisture uptake, and drug-excipient compatibility using DSC and FT-IR. RESULTS: All the selected films started to disintegrate in less than 14 seconds. Selected optimum films exhibited good mechanical properties with a folding endurance value greater than 100. The uniformity in weight, thickness, and drug content in the selected films was obtained. Surface pH was within the normal range (6.4 - 6.8). A smooth surface of the films was obtained and drugexcipient compatibility was proved using DSC and FT-IR. The dissolution test was done for optimum film formulations by simulating the oral cavity physiological conditions using the conventional dissolution test apparatus. More than 87% of the drug was released by the 4th minute. CONCLUSION: Orodispersible film of desloratadine was successfully prepared by solvent casting method in order to improve the disintegration/dissolution of the drug in oral cavity and hence better patient compliance and effective therapy.

Continuous Monitoring of the Hydration Behavior of Hydrophilic Matrix Tablets Using Time-Domain NMR.

Time-domain NMR (TD-NMR) was used for continuous monitoring of the hydration behavior of hydrophilic matrix tablets. The model matrix tablets comprised high molecular weight polyethylene oxide (PEO), hydroxypropyl methylcellulose (HPMC), and polyethylene glycol (PEG). The model tablets were immersed in water. Their T2 relaxation curves were acquired by TD-NMR with solid-echo sequence. A curve-fitting analysis was conducted on the acquired T2 relaxation curves to identify the NMR signals corresponding to the nongelated core remaining in the samples. The amount of nongelated core was estimated from the NMR signal intensity. The estimated values were consistent with the experiment measurement values. Next, the model tablets immersed in water were monitored continuously using TD-NMR. The difference in hydration behaviors of the HPMC and PEO matrix tablets was then characterized fully. The nongelated core of the HPMC matrix tablets disappeared more slowly than that of the PEO matrix tablets. The behavior of HPMC was significantly affected by the PEG content in the tablets. It is suggested that the TD-NMR method has potential to be utilized to evaluate the gel layer properties, upon replacement of the immersion medium: purified (nondeuterated) water is replaced with heavy (deuterated) water. Finally, drug-containing matrix tablets were tested. Diltiazem hydrochloride (a highly water-soluble drug) was employed for this experiment. Reasonable in vitro drug dissolution profiles, which were in accordance with the results from TD-NMR experiments, were observed. We concluded that TD-NMR is a powerful tool to evaluate the hydration properties of hydrophilic matrix tablets.

The Impact of Hypromellose on Pharmaceutical Properties of Alginate Microparticles as Novel Drug Carriers for Posaconazole.

Fungal infections are a group of diseases which are challenging to treat because of drug-resistant fungi species, drug toxicity, and often severe patient conditions. Hence, research into new treatments, including new therapeutic substances and novel drug delivery systems, is being performed. Mucoadhesive dosage forms are beneficial to improving drug bioavailability by prolonging the residence time at the site of application. Sodium alginate is a natural polymer with favorable mucoadhesive and gelling properties, although its precipitation in acidic pH significantly disrupts the process of drug release in gastric conditions. Hypromellose is a hydrophilic, semi-synthetic cellulose derivative with mucoadhesive properties, which is widely used as a control release agent in pharmaceutical technology. The aim of this study was to evaluate the impact of hypromellose on alginate microparticles with posaconazole, designed to modify drug release and to improve their mucoadhesive properties for both oral or vaginal application.

Increased bioavailability of a P-gp substrate: Co-release of etoposide and zosuquidar from amorphous solid dispersions.

P-glycoprotein (P-gp) inhibitors, like zosuquidar, partly increase oral bioavailability of P-gp substrates, such as etoposide. Here, it was hypothesised that co-release of etoposide and zosuquidar from amorphous solid dispersions (ASDs) may further increase oral etoposide bioavailability. This was envisioned through simultaneous co-release and subsequent spatiotemporal association of etoposide and zosuquidar in the small intestinal lumen. To further achieve this, ASDs of etoposide and zosuquidar in polyvinylpyrrolidone (PVP), hydroxypropylmethyl cellulose (HPMC) 5, and HPMC 4 k were prepared by freeze-drying. From these ASDs, etoposide release was fastest from PVP, then HPMC 5 and slowest from HPMC 4. Release from PVP and HPMC5 resulted in stable supersaturations of etoposide. In transcellular permeability studies across MDCKII-MDR1 cell monolayers, the accumulated amount of etoposide increased 3.7-4.9-fold from amorphous etoposide or when incorporated into PVP- or HPMC 5-based ASDs, compared to crystalline etoposide. In vivo, the oral bioavailability in Sprague Dawley rats increased from 1.0 to 2.4-3.4 %, when etoposide was administered as amorphous drug or in ASDs. However, when etoposide and zosuquidar were co-administered, the oral bioavailability increased further to 8.2-18 %. Interestingly, a distinct increase in oral etoposide bioavailability to 26 % was observed when etoposide and zosuquidar were co-administration in HPMC5-based ASDs. The supersaturation of etoposide as well as the simultaneous co-release of etoposide and zosuquidar in the small intestinal lumen may explain the observed bioavailability increase. Overall, this study suggested that simultaneous co-release of an amorphous P-gp substrate and inhibitor may be a novel and viable formulation strategy to increase the bioavailability P-gp substrates.

The effect of the molecular structure of hydroxypropyl methylcellulose on the states of water, wettability, and swelling properties of cryogels prepared with and without CaO2.

Hydroxypropyl methylcellulose (HPMC) belongs to the cellulose ether family that has hydroxyl groups substituted by hydrophobic methyl groups (DS) and hydrophilic hydroxypropyl groups (MS). Herein, the interactions between water molecules and cryogels prepared with HPMC in the presence and absence of a linear nonionic surfactant, as well as CaO2 microparticles, which react with water producing O2, were systematically investigated by sorption experiments and Time-Domain Nuclear Magnetic Resonance. Regardless of the DS and MS, most water molecules presented transverse relaxation time t2 typical of intermediate water and a small population of more tightly bound water. HPMC cryogels with the highest DS of 1.9 presented the slowest swelling rate of 0.519 ± 0.053 gwater/(g.s) and the highest contact angle values 85.250o ± 0.004o, providing the best conditions for a slow reaction between CaO2 and water. The presence of surfactant favored hydrophobic interactions that allowed the polar head of the surfactant to be exposed to the medium, resulting in a higher swelling rate and lower contact angle values. The HPMC with the highest MS presented the fastest swelling rate and the lowest contact angle. These findings are relevant for the formulations and reactions, where tuning the swelling kinetics is crucial for the final application.

Updates on applications of low-viscosity grade Hydroxypropyl methylcellulose in coprocessing for improvement of physical properties of pharmaceutical powders.

Hydroxypropyl methylcellulose (HPMC) is an important polymeric excipient. Its versatility in terms of molecular weights and viscosity grades is the basis for its wide and successful application in the pharmaceutical industry. Low viscosity grades of HPMC (like E3 and E5) have been used as physical modifiers for pharmaceutical powders in recent years due to their unique physicochemical and biological properties (e.g., low surface tension, high Tg, strong hydrogen bonding ability, etc.). Such modification is the co-processing of HPMC with a drug/excipient to create composite particles (CPs) for the purpose of providing synergistic effects of functional improvement as well as of masking undesirable properties of the powder (e.g., flowability, compressibility, compactibility, solubility, stability, etc.). Therefore, given its irreplaceability and tremendous opportunities for future developments, this review summarized and updated studies on improving the functional properties of drugs and/or excipients by forming CPs with low-viscosity HPMC, analyzed and exploited the improvement mechanisms (e.g., improved surface properties, increased polarity, hydrogen bonding, etc.) for the further development of novel co-processed pharmaceutical powders containing HPMC. It also provides an outlook on the future applications of HPMC, aiming to provide a reference on the crucial role of HPMC in various areas for interested readers.

Ocular Delivery of Metformin for Sustained Release and in Vivo Efficacy.

Metformin is known to lower inflammation, independent of its anti-diabetic action. Thus, topical metformin can be a therapeutic strategy for managing ocular inflammation associated with diabetes. To achieve this and address the issues of ocular retention and controlled release an in situ gel of metformin was developed. The formulations were prepared using sodium hyaluronate, hypromellose, and gellan gum. The composition was optimized by monitoring gelling time/capacity, viscosity, and mucoadhesion. MF5 was selected as the optimized formulation. It showed both chemical and physiological compatibility. It was found to be sterile and stable. MF5 exhibited sustained release of metformin for 8h that fitted best with zero-order kinetics. Further, the release mode was found to be close to the Korsmeyer-Peppas model. Supported by an ex vivo permeation study, it showed potential for prolonged action. It showed a significant reduction in ocular inflammation that was comparable to that of the standard drug. MF5 shows translational potential as a safe alternative to steroids for managing ocular inflammation.

HPMC films functionalized by zein/carboxymethyl tamarind gum stabilized Pickering emulsions: Influence of carboxymethylation degree.

Pickering emulsions are promising systems to act as carriers of active hydrophobic components, and to improve compatibility and the water vapor barrier properties of bio-based films. This study aimed to investigated the effects of cinnamon essential oil Pickering emulsions (CEOEs) using zein/carboxymethyl tamarind gum as stabilizers on the mechanical, barrier, antibacterial and antioxidant properties of Hydroxypropyl methyl cellulose (HPMC) films, and assessed the influence of carboxymethylation degree. In addition, the effect of the packaging was studied on the shelf life of cherry tomatoes. Results showed that the droplet size reduced approximately from 93.03 to 10.59 µm with the increasing degree of substitution (DS), greatly facilitating the droplet uniform distribution in film matrix. Moreover, with the addition of CEOEs, significant increase was observed with the tensile strength from 8.46 to 25.41 MPa, and the water vapor permeability decreased from 6.18 × 10-10 to 4.24 × 10-10 g·m-1·s-1·Pa-1. The films exhibited good UV barrier properties without sacrificing the transparency after adding CEO. Furthermore, the antibacterial and antioxidant activities of the prepared films have also been greatly improved. Consequently, the CEOEs was an ideal alternative for incorporation with HPMC based films for increasing the shelf life of cherry tomatoes.

Interaction of polymers with bile salts - Impact on solubilisation and absorption of poorly water-soluble drugs.

Formulating poorly soluble drugs with polymers in the form of solid dispersions has been widely used for improving drug dissolution. Endogenous surface-active species present in the gut, such as bile salts, lecithin and other phospholipids, have been shown to play a key role in facilitating lipids and poorly soluble drugs solubilisation in the gut. In this study, we examined the possible occurrence of interactions between a model bile salt, sodium taurocholate (NaTC), and model spray dried solid dispersions comprising piroxicam and Hydroxypropyl Methylcellulose (HPMC), a commonly used hydrophilic polymer for solid dispersion preparation. Solubility measurements revealed the good solubilisation effect of NaTC on the crystalline drug, which was enhanced by the addition of HPMC, and further boosted by the drug formulation into solid dispersion. The colloidal behaviour of the solid dispersions upon dissolution in biorelevant media, with and without NaTC, revealed the formation of NaTC-HPMC complexes and other mixed colloidal species. Cellular level drug absorption studies obtained using Caco-2 monolayers confirmed that the combination of drug being delivered by solid dispersion and the presence of bile salt and lecithin significantly contributed to the improved drug absorption. Together with the role of NaTC-HPMC complexes in assisting the drug solubilisation, our results also highlight the complex interplay between bile salts, excipients and drug absorption.