Soluble Drugs Research Articles

Therapeutic Alleviation and Mechanism of Glabridin Liposome on Histamine-induced Atopic Dermatitis

Background: One of the primary flavonoids found in the Glycyrrhiza glabra is called glabridin, which has anti-inflammatory, anti-bacterial, and antineoplastic effects. However, the insolubility of glabridin in water limits its application. Liposomes can increase the solubility of insoluble drugs and improve their bioavailability. Objective: We examined the potential for the treatment of glabridin liposomes on histamine-induced atopic dermatitis. Materials and Methods: After GL treatment, histopathology, inflammatory cytokines, and atopic dermatitis-related proteins were used to evaluate the therapeutic effect of GL. Results: Glabridin liposomes alleviated histamine-induced scratching behavior; reduced mast cell proliferation, infiltration, and degranulation; and restrained the expression of associated pro-inflammatory cytokines. Additionally, glabridin liposomes restored nerve growth factor to normal levels and enhanced the expression of filaggrin to promote cuticle growth and repair skin damage caused by atopic dermatitis. Conclusion: Glabridin liposomes may relieve histamine-induced skin hypersensitivity and cortical hyperplasia by inhibiting the production of inflammatory cytokines, demonstrating their potential for the clinical treatment of atopic dermatitis.

Ternary solid dispersions of lacidipine: Enhancing dissolution and supersaturation maintenance through strategic formulation optimization

The study aimed to address the challenges related to insufficient dissolution and maintenance of supersaturation in binary solid dispersions. Lacidipine, categorized as a BCS class II drug, was employed as the model drug. A systematic screening of excipients was conducted to determine the most effective carriers for the formulations of the ternary solid dispersions, utilizing the solvent transfer method and equilibrium solubility measurements. Both binary and ternary solid dispersions were prepared via spray drying, and comprehensive physicochemical characterization confirmed the successful preparation of amorphous solid dispersions. In vitro dissolution tests, the ternary solid dispersion exhibited marked superiority over the binary solid dispersion in dissolution and maintenance of supersaturation. Furthermore, an exploration into the factors influencing the stability of ternary solid dispersions revealed their robust resistance under light-protected, room-temperature, and desiccated conditions. The formation of intermolecular hydrogen bonding within the molecules of the ternary solid dispersions significantly enhanced drug solubility and system stability. Strategic formulation optimization, coupled with judicious selection of suitable carrier types and ratios, may serve as a promising approach for designing supersaturated drug delivery systems.

Effect of DMSO on Structural Properties of DMPC and DPPC Liposome Suspensions.

The study and characterization of the biophysical properties of membranes and drug-membrane interactions represent a critical step in drug development, as biological membranes act as a barrier that the drug must overcome to reach its active site. Liposomes are widely used in drug delivery to circumvent the poor aqueous solubility of most drugs, improving systemic bioavailability and pharmacokinetics. Further, they can be targeted to deliver to specific disease sites, thus decreasing drug load, and reducing side effects and poor adherence to treatment. To improve drug solubility during liposome preparation, DMSO is the most widely used solvent. This raises concern about the potential effect of DMSO on membranes and leads us to investigate, using DSC and EPR, the influence of DMSO on the behavior of lipid model membranes of DMPC and DPPC. In addition, we tested the influence of DMSO on drug-membrane interaction, using compounds with different hydrophobicity and varying DMSO content, using the same experimental techniques. Overall, it was found that with up to 10% DMSO, changes in the bilayer fluidity or the thermotropic properties of the studied liposomes were not significant, within the experimental uncertainty. For higher concentrations of DMSO, there is a stabilization of both the gel and the rippled gel phases, and increased bilayer fluidity of DMPC and DPPC liposomes leading to an increase in membrane permeability.

Oral fast dissolving films for co-administration of breviscapine and matrine: Formulation optimization and in vitro characterization

Oral fast dissolving films (OFDFs) are popular dosage forms for enhanced oral absorption of active ingredients without experiencing gastrointestinal interference or first-pass metabolism. The primary challenge in OFDF design is balancing drug loading capacity with film properties, particularly for poorly soluble drugs. In the present work, an OFDF formulation containing co-amorphous mixture was successfully designed for co-administration of two natural products at a drug content of 14%. Breviscapine and matrine are commonly used for cardiovascular and cerebrovascular related diseases, but their clinical application was limited by low bioavailability, short biological half-life, and instability problems. Their co-administration as a compound remedy requires a novel product too enhance drug dissolution and patient compliance. A 33 Box-Behnken design was used to generate OFDF preparations by solvent casting method. The optimized blank film formulation, comprising 57.40% HPMC E50, 14.01% PEG 400 and 5.35% L-HPC, demonstrated a rapid disintegration in 18 s. XRD and FTIR analysis on drug-loaded films revealed good compatibility of drugs and polymers, and amorphous state of films with co-precipitates. The films were evaluated for morphology, folding endurance, disintegration time and in vitro BRE dissolution. Drugs incorporation extended the disintegration time of blank films, yet remained under 30 s. The co-amorphous mixture of BRE and MAT in films exhibited a faster BRE dissolution rate compared to the physical mixture. In conclusion, a compound OFDF formulation featuring a co-amorphous mixture of BRE and MAT offers an efficient strategy for hydrophobic drug delivery at high dose.

SOLUBILITY ENHANCEMENT OF ATAZANAVIR BY HYDROTROPIC SOLUBILIZATION TECHNIQUE

Objective: The present study aims to increase the solubility and dissolution of atazanavir sulfate (ATZ) by employing a hydrotropic solubilization technique. Methods: ATZ is a poorly soluble drug classified under the biopharmaceutical classification system (BCS)-II, which accounts for its poor oral bioavailability. Different hydrotropic agents, such as urea and sodium benzoate and their combinations at different ratios were prepared. The prepared hydrotropes were systematically investigated for compatibility between the drug and excipients using Fourier Transform Infra-Red Spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC) approaches. Further, in order to understand the conversion from crystalline to amorphous nature, X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) studies were also performed. The formulation of a mixed hydrotropic mixture comprising urea (2.5% w/v) and sodium benzoate (5% w/v) exhibited a 100.35±1.7 % drug release at 0.25 h with higher dissolution efficiency as compared with other batches of individual hydrotrope, mixed hydrotropes as well as pure drug. Results: FTIR studies revealed that there is no incompatibility between the drug and the selected hydrotropes. DSC studies also confirmed the fact that there is no interaction between the drug and the hydrotropes by the disappearance of an endothermic peak. XRD studies revealed that there was a significant reduction in the intensity of peaks, indicating the conversion of crystalline to the amorphous form. The SEM studies indicated that the drug appears crystalline in the shape of an irregular tiny prismatic needle, indicating its crystallinity. At the same time, the hydrotrope mixtures appeared in agglomerated form with a porous nature, which may be accountable for its increase in solubility. The hydrotropes prepared using urea alone exhibited an increase in solubility of 4.42 folds, and the hydrotrope prepared using sodium benzoate alone exhibited an increase in solubility of 3.178 folds; the combination hydrotropes of urea and sodium benzoate exhibited an increase in solubility of 8.78 folds in water as compared to pure drug. The drug release from the mixed hydrotropes obeys zero-order kinetics with diffusion as the main mechanism. Conclusion: The present investigation concluded that the combination of hydrotropes enhanced the solubility of the aqueous soluble drug ATZ. However, in vivo studies are essential to establish its potential effect.

APPROACH TO OPTIMIZE THE SELF-MICROEMULSIFYING DRUG DELIVERY SYSTEM FOR AZILSARTAN MEDOXOMIL USING BOX BEHNKEN DESIGN AND DESIRABILITY FUNCTION

Objective: Develop and optimize a novel self-micro emulsifying drug delivery system (SMEDDS) for enhancing the water solubility of Azilsartan (AZL) by employing the Box-Behnken design and the desirability function. Methods: The formulation of AZL-SMEDDS consists of clove oil (oil component), Tween 20 (surfactant), propylene glycol (co-surfactant) as the independent variables and the active drug. Using a 3-level Design, the impact of independent variables on the formulation was examined. These variables' specified ranges are 20-40 mg, 50-80 mg, and 5-30 mg for X1, X2 and X3 respectively. Particle size (Y1), PDI (Y2), and dissolution % (Y3) were the response variables investigated in this study. Results: The results indicated that the optimal values for Clove oil (X1), Tween 20 (X2), and Propylene glycol (X3) were determined to be 28.69, 76.45, and 24.93 (mg), respectively. Based on these optimized conditions, the predicted data points for the response variables Particle Size (Y1), Polydispersity (Y2), and dissolution % (Y3) were determined to be 59.85 nm, 0.729 and 55.406%, respectively. Conclusion: The empirical results obtained from the optimized formulation exhibited a strong correlation with the predicted values. The optimized AZL-SMEDDS formulation demonstrated a rapid rate of drug solubility and greater bioavailability than AZL powder.

Recent Trends in Nanocarrier-Based Drug Delivery System for Prostate Cancer.

Prostate cancer remains a significant global health concern, requiring innovative approaches for improved therapeutic outcomes. In recent years, nanoparticle-based drug delivery systems have emerged as promising strategies to address the limitations of conventional cancer chemotherapy. The key trends include utilizing nanoparticles for enhancing drug delivery to prostate cancer cells. Nanoparticles have some advantages such as improved drug solubility, prolonged circulation time, and targeted delivery of drugs. Encapsulation of chemotherapeutic agents within nanoparticles allows for controlled release kinetics, reducing systemic toxicity while maintaining therapeutic efficacy. Additionally, site-specific accumulation within the prostate tumor microenvironment is made possible by the functionalization of nanocarrier with targeted ligands, improving therapeutic effectiveness. This article highlights the basics of prostate cancer, statistics of prostate cancer, mechanism of multidrug resistance, targeting approach, and different types of nanocarrier used for the treatment of prostate cancer. It also includes the applications of nanocarriers for the treatment of prostate cancer and clinical trial studies to validate the safety and efficacy of the innovative drug delivery systems. The article focused on developing nanocarrier-based drug delivery systems, with the goal of translating these advancements into clinical applications in the future.

Development of a physiologically-based pharmacokinetic model to simulate the pharmacokinetics of intramuscular antiretroviral drugs.

There is growing interest in the use of long-acting (LA) injectable drugs to improve treatment adherence. However, their long elimination half-life complicates the conduct of clinical trials. Physiologically-based pharmacokinetic (PBPK) modeling is a mathematical tool that allows to simulate unknown clinical scenarios for LA formulations. Thus, this work aimed to develop and verify a mechanistic intramuscular PBPK model. The framework describing the release of a LA drug from the depot was developed by including both the physiology of the injection site and the physicochemical properties of the drug. The framework was coded in Matlab® 2020a and implemented in our existing PBPK model for the verification step using clinical data for LA cabotegravir, rilpivirine, and paliperidone. The model was considered verified when the simulations were within twofold of observed data. Furthermore, a local sensitivity analysis was conducted to assess the impact of various factors relevant for the drug release from the depot on pharmacokinetics. The PBPK model was successfully verified since all predictions were within twofold of observed clinical data. Peak concentration, area under the concentration-time curve, and trough concentration were sensitive to media viscosity, drug solubility, drug density, and diffusion layer thickness. Additionally, inflammation was shown to impact the drug release from the depot. The developed framework correctly described the release and the drug disposition of LA formulations upon intramuscular administration. It can be implemented in PBPK models to address pharmacological questions related to the use of LA formulations.

Ion-activated In Situ Gel of Gellan Gum Containing Chrysin for Nasal Administration in Parkinson's Disease.

This study focused on creating an innovative treatment approach for Parkinson's disease (PD), a progressive neurodegenerative condition characterized by the loss of specific neurons in the brain. The research aimed to develop a nasal gel using gellan gum containing a complex of chrysin with hydroxypropyl-β-cyclodextrin (HP-β-CD) to enhance the drug's solubility and stability. The formulation process involved utilizing central composite design (CCD) to optimize the concentrations of gellan gum and HPMC E5, with viscosity and mucoadhesive strength as key factors. The resulting optimized In Situ gel comprised 0.7% w/v gellan gum and 0.6% w/v HPMC E5, exhibiting desirable viscosity levels for both sol and gel states, along with robust mucoadhesive properties. The formulated gel underwent comprehensive evaluation, including assessments for gelation, drug content, in vitro drug release, ex vivo permeation, and histopathology. The findings demonstrated superior drug release from the In Situ gel compared to standalone chrysin. Ex vivo studies revealed effective drug permeation through nasal mucosa without causing harm. Moreover, experiments on neuronal cells exposed to oxidative stress (H2O2- induced) showcased significant neuroprotection conferred by chrysin and its formulations. These treatments exhibited notable enhancements in cell viability and reduced instances of apoptosis and necrosis, compared to the control group. The formulations exhibited neuroprotective properties by mitigating oxidative damage through mechanisms, like free radical scavenging and restoration of antioxidant enzyme activity. In conclusion, this developed In situ gel formulation presents a promising novel nasal delivery system for PD therapy. By addressing challenges related to drug properties and administration route, it holds the potential to enhance treatment outcomes and improve the quality of life for individuals with Parkinson's disease.

The influence of natural polymers on loratadine's solubility and dissolution profiles.

Second-generation tricyclic H1 antihistamine loratadine (LTD) has a high permeability, low water solubility, and an oral absorption rate dependent on the rate at which it dissolves in the gastrointestinal tract. One approach suggested for improving the drug's solubility and rate of dissolution is natural solid dispersion (NSD). The present study evaluated the use of hydrophilic natural polymers, sodium alginate (SA), hyaluronic acid (HA), and xyloglucan (XG), in natural solid dispersion to enhance LTD solubility and dissolution rate. A total of 12 formulations comprising varied drug-to-polymer ratios were produced and analyzed for percentage yield, water solubility, and in vitro dissolution rate. The solubility of LTD was improved in all formulations. Excellent results were achieved with NSD1 (LTD: SA 1:0.25), with a high yield (99%), superior solubility (0.187) compared to pure loratadine (0.0021), and a speedy dissolution rate (98%) within 30 minutes. These studies suggest natural polymers like SA, HA, and XG can considerably increase LTD solubility. When introduced into NSD, these polymers effectively augment LTD dissolving rates, presenting attractive prospects for better bioavailability and therapeutic efficacy.

Drug Polymorphism: An Important Pre-formulation Tool in the Formulation Development of a Dosage Form

Abstract: Polymorphism permits solids to have two or multiple crystal structures with varying orientations or conformations, and polymorph drug dissolution and solubility vary. Polymorphism influences drug efficacy, bioavailability and toxicity. Various parameters can regulate polymorph crystallization, including supersaturation phase, temperature, stirring rate, solvent addition rate, seed crystal, additives and pH. To characterize and monitor polymorphs, various analytical approaches are available, including powder X-Ray diffraction / X-Ray diffraction (PXRD/XRD), also called as Gold Standard method, differential scanning calorimetry (DSC), Infrared spectroscopy (IR), and microscopical studies. To prevent polymorphic change during production, distribution, and storage, formulation with the most stable form in the marketed product is considered. In addition, by monitoring each phase of raw material processing, polymorphisms can be controlled during dosage form manufacturing. The objective of this review is to provide concise information on drug polymorphism, their characterization process, their effect on the stability of dosage forms, factors controlling polymorphism in the crystallization process, some case studies on polymorphs, control of polymorphism during the formulation of successful dosage forms and some of the regulatory considerations regarding polymorphs. Various databases like Pubmed/Medline, Google Scholar and Web of Science of all English language articles were searched, and relevant information was collected regarding the importance of polymorphism in formulation development. From a vast literature survey, it was found that polymorphism is a very important tool in a pre-formulation study that provides information about the fate of a drug molecule in its journey. From the present study, it was concluded that the polymorphism property of a drug should be taken into consideration at the pre-formulation stage since it is a very important tool for the formulation of a successful dosage form with stability and efficacy.

Crushing tablets or sprinkling capsules: Implications for clinical strategy and study performance based on BE studies of rivaroxaban and deferasirox.

Administration of oral medicinal products as crushed tablets or open capsules is an important delivery option for patients suffering from dysphagia. To obtain full interchangeability of generics with the original products, demonstration of bioequivalence (BE) between both products administered as crushed tablets/open capsules was required for poorly soluble product by European Medicines Agency (EMA) at the time of development of our rivaroxaban and deferasirox generic products. We present the results of two BE studies with modified administration of these products, which compared relative bioavailability between generic and reference products. In the rivaroxaban study, the test product was administered as a capsule sprinkled on and mixed with applesauce, whereas the reference tablet was crushed and administered with applesauce under fed conditions. In the deferasirox study, both treatments were administered as crushed tablets under fasting conditions. Both studies applied a two-way crossover design and were conducted after a single-dose in healthy volunteers. The 90% confidence interval of the geometric mean ratio area under the analyte concentration versus time curve, from time zero to the time of the last measurable analyte concentration and maximum measured analyte concentration over the sampling period of the test to reference ratio were 103.36-110.37% and 97.98-108.45% for rivaroxaban, respectively, and 96.69-107.29% and 94.19-109.45% for deferasirox, respectively. Thus, the BE criteria (80.00-125.00%) were met in both studies which demonstrated that bioavailability was not affected when the test and reference products were administered in the form of crushed tablet/open capsule. These results support the argument of redundancy of crushed product studies for poorly soluble drugs, which is in line with the currently revised position of the EMA on this topic.

A Recent Review on Nanocrystal Manufacturing Techniques with Pharmaceutical Application

Abstract: This review article constitutes an introductory report on nanotechnology focusing on the various manufacturing approaches of nanocrystals. Nanocrystals are a solid form to tackle the issue identified with poor fluid solvency. Hence, it is a useful technique in improving the bioa-vailability of various poorly soluble drugs. On a broader way, nanocrystal technology is mainly classified as top-down technology, bottom-up technology and a combination of top-down and bottom-up technology. Top-down technology is based on the principle of breaking down a com-plex into small crystals. This process is executed by using high-pressure homogenization, laser ablation, media mills, ultrasound technology, vacuum dissolution, gas condensation and mechani-cal attrition. Bottom-up technology is based on the principle of preparation by gathering at-oms/molecules together. It is achieved by using precipitation, supercritical fluid, gel-gel technol-ogy, spray drying, hydrolysis, and condensation. Due to the diverse characteristics and properties of drugs, a combination of top-down and bottom-up techniques is best for manufacturing nano-crystals. Some of the promising technique includes nano-edge technology and smart-crystal tech-nology. These techniques are discussed in this review.

Thermodynamic Modeling of Solubility of Some Antibiotics in Supercritical Carbon Dioxide Using Simplified Equation of State Approach

Antibiotics are playing crucial role in the treatment of humans since the last few centuries. Their usage has several benefits along with side effects. The efficacy of antibiotics for the treatment of ailments may be retained by controlling the drug dosage. This may be achieved with supercritical fluid technology (SFT). The antibiotic drug solubility in supercritical carbon dioxide (scCO2) is available only at specific temperature and pressure conditions, for effective utilization of SFT, solubility at various conditions are required. Equation of state (EoS) method is used for solubility data modeling and it requires critical properties of the solute, molar volume of the solute and sublimation pressure of the solute along with fugacity coefficient, pressure and temperature. These properties are estimated using group contribution methods. For antibiotics solute critical properties, molar volume and sublimation pressure are unavailable and existing group contribution methods are also not applicable due to the lack of functional group contributions in their techniques. Thus, there is a need to address EoS methodology without using solute properties. Hence, a new EoS methodology for solubility modeling is, proposed without using critical properties of the solute, molar volume of the solute and vapour pressure of the solute. Thus, this study focuses on the development of new solubility model that correlates antibiotics using equation of state (EoS). Importantly, the proposed solubility model does not use the critical properties of the antibiotics. Correlating ability of the proposed model is indicated in terms of regression coefficient and arithmetic average relative deviation percentage (AARD %).

Biopolymer-based tumor microenvironment-responsive nanomedicine for targeted cancer therapy.

Nanomedicine has opened up new avenues for cancer treatment by enhancing drug solubility, permeability and targeted delivery to cancer cells. Despite its numerous advantages over conventional therapies, nanomedicine may exhibit off-target drug distribution, harming nontarget regions. The increased permeation and retention effect of nanomedicine in tumor sites also has its limitations, as abnormal tumor vasculature, dense stroma structure and altered tumor microenvironment (TME) may result in limited intratumor distribution and therapeutic failure. However, TME-responsive nanomedicine has exhibited immense potential for efficient, safe and precise delivery of therapeutics utilizing stimuli specific to the TME. This review discusses the mechanistic aspects of various TME-responsive biopolymers and their application in developing various types of TME-responsive nanomedicine.

Development of antifungal gel, composition and technology based on pomiferin metabolite isolated from fruits of Maclura aurantiaca growing in Kazakhstan

The aim. The purpose of this study is to develop the optimal composition and rational gel technology under the conventional name "Kaz-P7" based on the antifungal pomiferin.
 Materials and methods. The object of the study is the substance pomiferin.
 Based on the physicochemical properties of the gel (poorly soluble in water) and technological properties structurant - Carbopol Ultrez 20 (swelling) chosen optimal solvent system: DMSO-PG-water (1:4:1) corresponding to the maximum solubility of drug and polymer provides swelling.
 Following the requirements of GF RK I, vol. 1, 2.2.8, 2.2.10 was determined by rotational viscometric method. Rheological properties of the sample are determined using rotational viscometer "Rheolab QC" (firm "Anton Paar", Austria) with coaxial cylinders CC27/S-SN29766 determined. The rheological parameters were studied at a temperature of 20 °C – 35 °C using the MLM U15c thermostat included in the rheostat.
 Results. Gel dosage forms provide better bioavailability of the drug substance. In addition, gels are a more modern dosage form, pleasant in terms of organoleptic characteristics.
 The technology of gel manufacturing consists of two parallel processes: preparation of the drug substance solution and its introduction into the base. From the point of view of biopharmacy, which studies the biological effect of drugs depending on their physical properties, dosage form and preparation technology, the greatest release of the drug substance occurs when it is introduced into the dosage form in dissolved form.
 Pomiferin administered in the dissolved state has the most therapeutic effect on the gel base. At the same time, active pharmaceutical ingredients (APIs) were dissolved in different solvents with gradual heating. The ratio of solvents DMSO-PG-water (1:4:1) at which the developed dosage form will be more structured, stable, and thixotropic gel is established.
 Conclusions. Fungal skin diseases are among the most frequently discussed problems in the literature. The relevance of this topic is determined by the high prevalence of pathogens, which account for 37-42 % of all skin diseases. It was experimentally established that for the complete neutralization of one gm of carbopol Ultraz 20 in the DMSO-PG-water solvent system (1:4:1), one gm of triethanolamine (pH 7.0) is consumed. The optimal diluent consisting of DMSO-PG- water in the ratio (1:4:1) was selected by physico-chemical analysis methods, and one gm of triethanolamine (pH 7.0) was selected as the neutralizing agent. The following composition was chosen as the optimal gel model: API-3.0, DMSO-3.0, PG-50.0, Carbopol Ultrez 20-1.0, and Triethanolamine-1.0. The optimal composition and technology of the gel codenamed "Kaz-P7" based on the substance obtained by pomiferin was developed

Conjugated Linoleic Acid-Carboxymethyl Chitosan Polymeric Micelles to Improve the Solubility and Oral Bioavailability of Paclitaxel.

Oral delivery, the most common method of therapeutic administration, has two significant obstacles: drug solubility and permeability. The challenges of current oral medicine delivery are being tackled through an emerging method that uses structures called polymeric micelles. In the present study, polymeric micelles were developed using conjugates of linoleic acid-carboxymethyl chitosan (LA-CMCS) for the oral delivery of paclitaxel (PCL). The developed micelles were evaluated by particle size, zeta potential, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). When PCL was contained within micelles, its solubility increased by almost 13.65 times (around 60 µg/mL). The micelles' zeta potentials were -29 mV, their polydispersity indices were 0.023, and their particle diameters were 93 nm. Micelles showed PCL loading and entrapment efficiencies of 67% and 61%, respectively. The sustained release qualities of the PCL release data from micelles were good. In comparison to the pure PCL suspension, the permeability of the PCL from micelles was 2.2 times higher. The pharmacokinetic data revealed that PCL with LA-CMCS micelles had a relative bioavailability of 239.17%, which was much greater than the PCL in the suspension. The oral bioavailability of PCL was effectively increased by LA-CMCS micelles according to an in vivo study on animals. The polymer choice, maybe through improved permeability, plays an essential role when assessing oral bioavailability enhancement and solubility improvement (13.65 times). The outcomes demonstrated that PCL's solubility and pharmacokinetics were improved in the micelles of the LA-CMCS conjugate.

Agarose as a tunable platform for oral drug delivery: Controlled release of a highly soluble drug, theophylline, within a sequentially-changing-pH medium

The purpose of this study was to expand the use of freeze-dried agarose-based systems for the oral controlled release of highly water-soluble drugs. Three additives (Eudragit S-100 and RL-PO and Labrafac) were included within these systems together with Theophylline. The release of this drug from the rehydrated systems was evaluated in deionized water and in a sequentially-changing-pH medium that simulated the conditions under oral administration. Considering the results obtained in the preliminary release test in water, only the Eudragit-containing compositions were further characterized. The theophylline release in a sequentially-changing-pH medium showed two different patterns that mainly depend on the additive nature: those systems containing Eudragit S-100 showed a similar behaviour to that observed in the absence of additives while the presence of Eudragit RL-PO yields a progressive and pH-independent release. Agarose-based systems were capable of accommodating additives that allows tailoring a controlled release of theophylline, a highly soluble drug.

Design of Etched- and Functionalized-Halloysite/Meloxicam Hybrids: A Tool for Enhancing Drug Solubility and Dissolution Rate.

The study focuses on the synthesis and characterization of Meloxicam-halloysite nanotube (HNT) composites as a viable approach to enhance the solubility and dissolution rate of meloxicam, a poorly water-soluble drug (BCS class II). Meloxicam is loaded on commercial and modified halloysite (acidic and alkaline etching, or APTES and chitosan functionalization) via a solution method. Several techniques (XRPD, FT-IR, 13C solid-state NMR, SEM, EDS, TEM, DSC, TGA) are applied to characterize both HNTs and meloxicam-HNT systems. In all the investigated drug-clay hybrids, a high meloxicam loading of about 40 wt% is detected. The halloysite modification processes and the drug loading do not alter the structure and morphology of both meloxicam and halloysite nanotubes, which are in intimate contact in the composites. Weak drug-clay and drug-functionalizing agent interactions occur, involving the meloxicam amidic functional group. All the meloxicam-halloysite composites exhibit enhanced dissolution rates, as compared to meloxicam. The meloxicam-halloysite composite, functionalized with chitosan, showed the best performance both in water and in buffer at pH 7.5. The drug is completely released in 4-5 h in water and in less than 1 h in phosphate buffer. Notably, an equilibrium solubility of 13.7 ± 4.2 mg/L in distilled water at 21 °C is detected, and wettability dramatically increases, compared to the raw meloxicam. These promising results can be explained by the chitosan grafting on the outer surface of halloysite nanotubes, which provides increased specific surface area (100 m2/g) disposable for drug adsorption/desorption.

Development of lipid-based SEDDS using digestion products of long-chain triglyceride for high drug solubility: Formulation and dispersion testing

A self-emulsifying drug delivery system (SEDDS) containing long chain lipid digestion products (LDP) and surfactants was developed to increase solubility of two model weakly basic drugs, cinnarizine and ritonavir, in the formulation. A 1:1.2 w/w mixture of glyceryl monooleate (Capmul GMO-50; Abitec) and oleic acid was used as the digestion product, and a 1:1 w/w mixture of Tween 80 and Cremophor EL was the surfactant used. The ratio between LDP and surfactant was 1:1 w/w. Since the commercially available Capmul GMO-50 is not pure monoglyceride and contained di-and-triglycerides, the digestion product used would provide 1:2 stoichiometric molar ratio of monoglyceride and fatty acid after complete digestion in gastrointestinal fluid. Both cinnarizine and ritonavir had much higher solubility in oleic acid (536 and 72 mg/g, respectively) than that in glyceryl monooleate and glyceryl trioleate. Therefore, by incorporating oleic acid in place of glyceryl trioleate in the formulation, the solubility of cinnarizine and ritonavir could be increased by 5-fold and 3.5-fold, respectively, as compared to a formulation without the fatty acid. The formulation dispersed readily in aqueous media, and adding 3 mM sodium taurocholate, which is generally present in GI fluid, remarkably improved the dispersibility of SEDDS and reduced particle size of dispersions. Thus, the use of digestion products of long-chain triglycerides as components of SEDDS can enhance the drug loading of weakly basic compounds and increase dispersibility in GI fluids.