Development of andrographolide loaded PLGA microspheres: Optimization, characterization and in vitro–in vivo correlation

Quality-by-Design Based Development of Doxycycline Hyclate-Loaded Polymeric Microspheres for Prolonged Drug Release

This study explores a novel approach to address the challenges of delivering highly water-soluble drug molecules by employing hydrophobic ion-pairing (HIP) complexes within poly (lactic-co-glycolic acid) (PLGA) microspheres. The HIP complex, formed between doxycycline hyclate (DH) and docusate sodium (DS), renders the drug hydrophobic. The development of the microspheres was done using the QbD approach, namely, Box-Behnken Design (BBD). A comprehensive characterization of the HIP complex confirmed the successful conversion of DH. DH and the HIP complex were effectively loaded into PLGA microspheres using the oil-in-water (O/W) emulsion solvent evaporation method. Results demonstrated significant improvements in percentage entrapment efficiency (% EE) and drug loading (% DL) for DH within the HIP complex-loaded PLGA microspheres compared to DH-loaded microspheres alone. Additionally, the initial burst release of DH reduced to 3% within the initial 15 min, followed by sustained drug release over 8 days. The modified HIP complex strategy offers a promising platform for improving the delivery of highly water-soluble small molecules. It provides high % EE, % DL, minimal initial burst release, and sustained release, thus having the potential to enhance patient compliance and drug delivery efficiency.

Novel wine in an old bottle: Preventive and therapeutic potentials of andrographolide in atherosclerotic cardiovascular diseases

Atherosclerotic cardiovascular disease (ASCVD) frequently results in sudden death and poses a serious threat to public health worldwide. The drugs approved for the prevention and treatment of ASCVD are usually used in combination but are inefficient owing to their side effects and single therapeutic targets. Therefore, the use of natural products in developing drugs for the prevention and treatment of ASCVD has received great scholarly attention. Andrographolide (AG) is a diterpenoid lactone compound extracted from Andrographis paniculata. In addition to its use in conditions such as sore throat, AG can be used to prevent and treat ASCVD. It is different from drugs that are commonly used in the prevention and treatment of ASCVD and can not only treat obesity, diabetes, hyperlipidaemia and ASCVD but also inhibit the pathological process of atherosclerosis (AS) including lipid accumulation, inflammation, oxidative stress and cellular abnormalities by regulating various targets and pathways. However, the pharmacological mechanisms of AG underlying the prevention and treatment of ASCVD have not been corroborated, which may hinder its clinical development and application. Therefore, this review summarizes the physiological and pathological mechanisms underlying the development of ASCVD and the in vivo and in vitro pharmacological effects of AG on the relative risk factors of AS and ASCVD. The findings support the use of the old pharmacological compound ('old bottle') as a novel drug ('novel wine') for the prevention and treatment of ASCVD. Additionally, this review summarizes studies on the availability as well as pharmaceutical and pharmacokinetic properties of AG, aiming to provide more information regarding the clinical application and further research and development of AG.

Mannosylated-Chitosan-Coated Andrographolide Nanoliposomes for the Treatment of Hepatitis: In Vitro and In Vivo Evaluations

A key diterpene lactone of Andrographis paniculata, i.e., andrographolide (AG), exhibits a variety of physiological properties, including hepatoprotection. The limited solubility, short half-life, and poor bioavailability limits the pharmacotherapeutic potential of AG. Therefore, in this study we aimed to formulate and optimize AG-loaded nanoliposomes (AGL) using the Design of Experiment (DOE) approach and further modify the surface of the liposomes with mannosylated chitosan to enhance its oral bioavailability. Physical, morphological, and solid-state characterization was performed to confirm the formation of AGL and Mannosylated chitosan-coated AGL (MCS-AGL). Molecular docking studies were conducted to understand the ligand (MCS) protein (1EGG) type of interaction. Further, in vitro release, ex vivo drug permeation, and in vivo pharmacokinetics studies were conducted. The morphological studies confirmed that AGL was spherical and a layer of MCS coating was observed on their surface, forming the MCS-AGL. Further increase in the particle size and change in the zeta potential of MCS-AGL confirms the coating on the surface of AGL (375.3 nm, 29.80 mV). The in vitro drug release data reflected a sustained drug release profile from MCS-AGL in the phosphate buffer (pH 7.4) with 89.9 ± 2.13% drug release in 8 h. Ex vivo permeation studies showed higher permeation of AG from MCS-AGL (1.78-fold) compared to plain AG and AGL (1.37-fold), indicating improved permeability profiles of MCS-AGL. In vivo pharmacokinetic studies inferred that MCS-AGL had a 1.56-fold enhancement in AUC values compared to plain AG, confirming that MCS-AGL improved the bioavailability of AG. Additionally, the 2.25-fold enhancement in the MRT proves that MCS coating also enhances the in vivo stability and retention of AG (stealth effect). MCS as a polymer therefore has a considerable potential for improving the intestinal permeability and bioavailability of poorly soluble and permeable drugs or phytoconstituents when coated over nanocarriers.

Development of andrographolide-loaded solid lipid nanoparticles for lymphatic targeting: Formulation, optimization, characterization, in vitro, and in vivo evaluation

Andrographolide, the primary bioactive constituent of Andrographis paniculata, is a promising natural substance with numerous pharmacotherapy uses. Low water solubility, short half-life, and low permeability necessitate the development of a delivery system that enhances its entrapment efficiency, bioavailability, lymphatic targeting, and by-pass hepatic effect. The andrographolide-loaded solid lipid nanoparticles were fabricated by melt-emulsification and ultrasonication and optimized with Design-Expert software. In the optimal formulation, Glycerol monostearate as the solid lipid and Poloxamer 407 and Span 60 as surfactants were used. Optimum AND-SLN was observed to have a mean particle size, polydispersity index, zeta potential, and entrapment efficiency of 193.84 nm, 0.211, - 22.8 mV, and 83.70% respectively. An optimized formulation was characterized by examining surface morphology, X-ray diffraction, and differential scanning calorimetry. In vitro studies have shown sustained drug release from AND-SLN for up to 24 h. The stability studies showed that there was no significant change in the mean particle size and entrapment efficiency after storage at 4 ± 2 °C and 25 ± 2 °C/60 ± 5% RH. In in vivo pharmacokinetics studies, AND-SLN was found to have enhanced bioavailability and specificity in the spleen and thymus compared to plasma, providing evidence that the formulations could enhance target specificity and bioavailability in comparison to pure drugs. The H&E staining of the liver, spleen, and thymus treated with the AND-SLN revealed no signs of damage histopathologically. Thus, AND-SLN possess a high potential for improved efficacy and are an efficient vehicle for delivering drugs to the lymphatic system.

Nanomicelles co-loaded with doxorubicin and salvianolic acid A for breast cancer chemotherapy

Background

Multi-drug delivery system based on polymer carrier is emerging for alleviating dose-limiting toxicities of first-line cytotoxic anticancer drugs, such as doxorubicin (DOX) for breast cancer chemotherapy. By co-loading the premium natural antioxidant salvianolic acid A (SAA) through colloidal self-assembly of amphiphilic copolymer, we herein developed CPMSD, a complex polymeric micellar system to overcome cardiotoxicity associated with DOX.

Results

Optimal formulation was obtained by DOE study and CPMSD micelles were well constructed by using mPEG-PCL for entrapment at a drug–carrier mass ratio of 1:5 and DOX–SAA mass ratio of 1:4. Molecular dynamics simulation revealed the ratiometrical co-encapsulation of SAA into the hydrophobic cavity but DOX to ball-shaped surface of micelles due to hydrophilicity. Characterization study manifested favorable biopharmaceutical properties, such as small and uniform particle size, fairly high drug loading capacity, as well as good colloidal stability and controlled drug release. CPMSD maintained anticancer efficacy of DOX and the action mechanism, which did not be affected by co-administering SAA. More to the point, it was of great benefit to systemic safety and cardioprotective effect against oxidative stress injuries associated with DOX in tumor-bearing mice.

Conclusions

All the findings substantiated that CPMSD would be a promising multifunctional nanosystem of DOX for breast cancer chemotherapy.

PLGA sustained-release microspheres loaded with an insoluble small-molecule drug: microfluidic-based preparation, optimization, characterization, and evaluation in vitro and in vivo

Microspheres play an important role in controlling drug delivery and release rate accurately. To realize the sustainable release of insoluble small-molecule drugs, a new three-phase flow-focusing microfluidic device was developed to produce the drug-loaded sustained-release microspheres which were prepared with bicalutamide (BCS class-II) as the model drug and poly(lactide-co-glycolide) (PLGA) as the carrier material. Under optimized prescription conditions, the microspheres showed a smooth surface and uniform size of 51.33 μm with a CV value of 4.43%. Sustained-release microspheres had a releasing duration of around 40 days in vitro without any initial burst release. The drug release mechanism of the microspheres was drug diffusion and polymer erosion. Meanwhile, the drug release of microspheres in vivo could be up to 30 days. Briefly, the microfluidic device in this study provides a new solution for the preparation of sustained-release microspheres for insoluble small-molecule drugs. PLGA sustained-release microspheres developed by the microfluidic device have good application prospects in precise delivery and sustainable release of insoluble small-molecule drugs.

Bioactive Based Nanocarriers for the Treatment of Viral Infections and SARS-CoV-2

Since ancient times, plants have been used for their medicinal properties. They provide us with many phytomolecules, which serve a synergistic function for human well-being. Along with anti-microbial, plants also possess anti-viral activities. In Western nations, about 50% of medicines were extracted from plants or their constituents. The spread and pandemic of viral diseases are becoming a major threat to public health and a burden on the financial prosperity of communities worldwide. In recent years, SARS-CoV-2 has made a dramatic lifestyle change. This has promoted scientists not to use synthetic anti-virals, such as protease inhibitors, nucleic acid analogs, and other anti-virals, but to study less toxic anti-viral phytomolecules. An emerging approach includes searching for eco-friendly therapeutic molecules to develop phytopharmaceuticals. This article briefly discusses numerous bioactive molecules that possess anti-viral properties, their mode of action, and possible applications in treating viral diseases, with a special focus on coronavirus and various nano-formulations used as a carrier for the delivery of phytoconstituents for improved bioavailability.

An insight into the pharmacological and analytical potential of Andrographolide

Andrographis paniculata is an annual medicinal herb from the family Acanthaceae. Andrographolide is generally considered an essential bioactive component of plant A. paniculata. Since ancient times, it has been widely recognized for its therapeutic qualities and has attracted the scientific and medical communities' attention. This review summarizes the molecular, clinical, and in vitro research of compound andrographolide and its mechanism of action. Andrographolide, when combined with other enhancing agents, offers a wide variety of health benefits. The therapeutic potential of andrographolide has been exemplified and exhibited by directly regulating genes and indirectly interacting with small molecules and different enzymes. This review compiles and consolidates the pharmacological action of andrographolide and its analogs and deciphers the gaps that have hindered its use in medicinal research.

Andrographolide: A review of its pharmacology, pharmacokinetics, toxicity and clinical trials and pharmaceutical researches

Andrographis paniculata (Burm. f.) Wall. ex Nees, a renowned herb medicine in China, is broadly utilized in traditional Chinese medicine (TCM) for the treatment of cold and fever, sore throat, sore tongue, snake bite with its excellent functions of clearing heat and toxin, cooling blood and detumescence from times immemorial. Modern pharmacological research corroborates that andrographolide, the major ingredient in this traditional herb, is the fundamental material basis for its efficacy. As the main component of Andrographis paniculata (Burm. f.) Wall. ex Nees, andrographolide reveals numerous therapeutic actions, such as antiinflammatory, antioxidant, anticancer, antimicrobial, antihyperglycemic and so on. However, there are scarcely systematic summaries on the specific mechanism of disease treatment and pharmacokinetics. Moreover, it is also found that it possesses easily ignored security issues in clinical application, such as nephrotoxicity and reproductive toxicity. Thereby it should be kept a lookout over in clinical. Besides, the relationship between the efficacy and security issues of andrographolide should be investigated and evaluated scientifically. In this review, special emphasis is given to andrographolide, a multifunctional natural terpenoids, including its pharmacology, pharmacokinetics, toxicity and pharmaceutical researches. A brief overview of its clinical trials is also presented. This review intends to systematically and comprehensively summarize the current researches of andrographolide, which is of great significance for the development of andrographolide clinical products. Noteworthy, those un-cracked issues such as specific pharmacological mechanisms, security issues, as well as the bottleneck in clinical transformation, which detailed exploration and excavation are still not to be ignored before achieving integration into clinical practice. In addition, given that current extensive clinical data do not have sufficient rigor and documented details, more high-quality investigations in this field are needed to validate the efficacy and/or safety of many herbal products.

Antiviral Activities of Andrographolide and Its Derivatives: Mechanism of Action and Delivery System

Andrographispaniculata (Burm.f.) Nees has been used as a traditional medicine in Asian countries, especially China, India, Vietnam, Malaysia, and Indonesia. This herbaceous plant extract contains active compounds with multiple biological activities against various diseases, including the flu, colds, fever, diabetes, hypertension, and cancer. Several isolated compounds from A. paniculata, such as andrographolide and its analogs, have attracted much interest for their potential treatment against several virus infections, including SARS-CoV-2. The mechanisms of action in inhibiting viral infections can be categorized into several types, including regulating the viral entry stage, gene replication, and the formation of mature functional proteins. The efficacy of andrographolide as an antiviral candidate was further investigated since the phytoconstituents of A. paniculata exhibit various physicochemical characteristics, including low solubility and low bioavailability. A discussion on the delivery systems of these active compounds could accelerate their development for commercial applications as antiviral drugs. This study critically reviewed the current antiviral development based on andrographolide and its derivative compounds, especially on their mechanism of action as antiviral drugs and drug delivery systems.

Multivesicular liposomal depot system for sustained delivery of risperidone: development, characterization, and toxicity assessment

OBJECTIVE

Considering the limitations of conventional risperidone (RSP) therapies, the present research characterizes the usefulness of multivesicular liposomes (MVLs) as an efficient controlled-release carrier for this widely used antipsychotic drug, to be employed for the treatment of schizophrenia.

METHODS

A 2³ full factorial design based on three independent variables was implemented to plan the experiments: the molar ratios of lipid to the drug, triolein to phospholipid, and cholesterol to phospholipid. The impacts of these parameters on the risperidone encapsulation efficiency and its release pattern within the first 24 and 48 h were investigated as dependent variables. Then, the optimized liposomal system was further in-depth analyzed in terms of size, morphological and structural features, release profile over 15 days, biocompatibility, and stability.

RESULTS

Optimized formulation parameters gave rise to MVLs possessing a spherical morphology with a median diameter of about 8 μm, a relatively narrow size distribution (span value of 1.49), and an encapsulation efficiency of 57.6%. These carriers not only exhibited a sustained-release behavior in vitro, lasting until the end of the 15 days but also underwent a negligible change in their size and RSP incorporation over two months at refrigerator condition. Furthermore, in vitro cytotoxicity and hemolysis assessments revealed that the optimized MVL formulation is biocompatible.

CONCLUSION

This study revealed the potential of MVLs as a promising system for the delivery of RSP and could open a new vista for the successful management of schizophrenia.

Current Trends on Repurposing and Pharmacological Enhancement of Andrographolide

Andrographolide, the main bioactive component separated from Andrographis paniculata in 1951, has been scrutinized with a modern drug discovery approach for anti-inflammatory properties since 1984. Identification of new uses of existing drugs can be facilitated by searching for evidence linking them to known or yet undiscovered drug targets and human disease states to develop new therapeutic indications.Furthermore, a wide spectrum of biological properties of andrographolide such as anticancer, antibacterial, antiviral, hepatoprotective, antioxidant, anti-malarial, anti-atherosclerosis are also reported. However, poor water solubility and instability limit its clinical application. It becomes crucial to enhance its pharmacological function and find a new treatment option for more diseases. Therefore, this article reviews the major recent developments in andrographolide, including repurposing applications in different diseases and underlying mechanisms, particularly focusing on pharmacological enhancement of andrographolide such as derivatives, chemical modifications with potent biological activity and drug delivery. The repurposing and pharmacological enhancement of andrographolide would not only have exciting therapeutic potential to different diseases to facilitate drug marketing, but also decrease the economic burden on healthcare worldwide.

Phytochemical add-on therapy to DMARDs therapy in rheumatoid arthritis: In vitro and in vivo bases, clinical evidence and future trends

The use of biologically active compounds derived from plants i.e. phytochemicals, have been known for ages for their pharmacological activities in the treatment of autoimmune disorders like rheumatoid arthritis (RA). Besides enormous scientific evidence, the therapeutic potential of phytochemicals is often undervalued. The treatment in RA involves the use of synthetic and biological disease modifying anti-rheumatic drugs (DMARDs). However, the long-term treatment in RA is associated with the risk of gastrointestinal, liver, pulmonary and renal toxicities and serious infections including latent tuberculosis, pneumococcus influenza, herpes zoster and hepatitis. These adverse effects sometimes lead to discontinuation of the therapy. A relatively new vision based on the combination of DMARDs with phytochemicals exhibiting anti-inflammatory, anti-arthritic, anti-oxidant, hepatoprotective and nephroprotective properties for the treatment of RA has achieved substantial importance in the last decade. From this perspective, the present review focuses on the combination of DMARDs (primarily MTX) with phytochemicals that have shown synergistic therapeutic effects while decreasing the toxic repercussions of current RA therapy. The review covers recent evidences of such combination studies that have shown promising results both in experimental arthritic models and clinical arthritis. Few of the combinations including resveratrol, sinomenine, coenzyme Q10 exhibited considerable interest because of their efficacy as an adjuvant to the MTX/standard DMARDs therapy in clinical trials. Besides giving an overview of such combination studies the review also critically discusses the limitations with the use of phytochemicals (e.g. solubility, permeability and bioavailability) compromising their clinical application. Additionally, it stresses upon the need of novel delivery systems and pharmaceutical technologies to increase the therapeutic efficacy of the combination therapy. Overall, the review unveils the potential of phytochemicals in combination with DMARDs with increased tolerability and superior efficacy in further refining the future of the RA therapy.

Preparation and Release Profiles in Vitro/Vivo of Galantamine Pamoate Loaded Poly (Lactideco-Glycolide) (PLGA) Microspheres

Patient’s poor compliance and the high risk of toxic effects limit the clinical use of galantamine hydrobromide. To overcome these drawbacks, the sustained-release galantamine pamoate microspheres (GLT-PM-MS) were successfully developed using an oil/water emulsion solvent evaporation method in this study. Physicochemical properties of GLT-PM-MS were carefully characterized, and the in vitro and in vivo drug release behaviors were well studied. Results showed that the morphology of optimized microspheres were spherical with smooth surfaces and core-shell interior structure. Mean particle size, drug loading and entrapment efficiency were 75.23 ± 1.79 μm, 28.01 ± 0.81% and 87.12 ± 2.71%, respectively. The developed GLT-PM-MS were found to have a sustained release for about 24 days in vitro and the plasma drug concentration remained stable for 17 days in rats. These results indicated that GLT-PM-MS could achieve the sustained drug release purpose and be used in clinical trial.

Antiviral effect of phytochemicals from medicinal plants: Applications and drug delivery strategies

Viral infections affect three to five million patients annually. While commonly used antivirals often show limited efficacy and serious adverse effects, herbal extracts have been in use for medicinal purposes since ancient times and are known for their antiviral properties and more tolerable side effects. Thus, naturally based pharmacotherapy may be a proper alternative for treating viral diseases. With that in mind, various pharmaceutical formulations and delivery systems including micelles, nanoparticles, nanosuspensions, solid dispersions, microspheres and crystals, self-nanoemulsifying and self-microemulsifying drug delivery systems (SNEDDS and SMEDDS) have been developed and used for antiviral delivery of natural products. These diverse technologies offer effective and reliable delivery of medicinal phytochemicals. Given the challenges and possibilities of antiviral treatment, this review provides the verified data on the medicinal plants and related herbal substances with antiviral activity, as well as applied strategies for the delivery of these plant extracts and biologically active phytochemicals. Graphical Abstract.

Investigation of 1,2-Dimyristoyl-sn-Glycero-3-Phosphoglycerol-Sodium (DMPG-Na) Lipid with Various Metal Cations in Nanocochleate Preformulation: Application for Andrographolide Oral Delivery in Cancer Therapy

This study aimed at carrying out a preformulation investigation of nanocochleates (NCs) and develop andrographolide-loaded nanocochleates. Preformulation study comprised of exploring the effect of trivalent and divalent ions on transition temperature (TT) of lipid (DMPG-Na), on particle size (PS), entrapment efficacy (EE), zeta potential (ZP) of NCs, and effect of NCs on change in lipid solubility post-NC formation. Further, the andrographolide-loaded nanocochleates made with CaCl₂ (ANDNCs) were characterized for ZP, PS, EE, X-ray powder diffraction (PXRD), differential scanning calorimetry (DSC), transition electron microscopy (TEM), in vitro release studies, in vitro anticancer potential on the cell line of human breast cancer (MCF-7), in vivo oral pharmacokinetic studies, and tissue distribution in female Wistar rats. Nanocochleates developed with CaCl₂ had a significant reduction in PS (1.78-fold) and ZP (1.38-fold), and elevation of EE (1.17-fold) as compared to AlCl₃ developed NCs. Trivalent ions demonstrated elevation of TT as compared to divalent ions. Spiral-shaped ANDNCs demonstrated ZP, PS, and EE of - 121.46 ± 15.12 mV, 360 ± 47 nm, and 68.12 ± 3.81% respectively. In vitro release study of ANDNCs showed a strong pH-dependent release profile due to hydrogen bonding between NCs and andrographolide (AND). Formulated ANDNCs demonstrated 26.99-fold decrease in IC50 value as compared to free AND. Additionally, the oral bioavailability of AND from ANDNCs improved by 1.81-fold as compared to free AND. Furthermore, ANDNCs showed minimum accumulation within the vital organs such as liver, kidney, and spleen. Briefly, the preformulation study laid a platform for better understanding the NCs and its components. Further, developed ANDNCs revealed superior physiochemical properties to be used as an alternative for a clinical setting.

Current status of in vivo bioanalysis of nano drug delivery systems

The development of nano drug delivery systems (NDDSs) provides new approaches to fighting against diseases. The NDDSs are specially designed to serve as carriers for the delivery of active pharmaceutical ingredients (APIs) to their target sites, which would certainly extend the benefit of their unique physicochemical characteristics, such as prolonged circulation time, improved targeting and avoiding of drug-resistance. Despite the remarkable progress achieved over the last three decades, the understanding of the relationships between the in vivo pharmacokinetics of NDDSs and their safety profiles is insufficient. Analysis of NDDSs is far more complicated than the monitoring of small molecular drugs in terms of structure, composition and aggregation state, whereby almost all of the conventional techniques are inadequate for accurate profiling their pharmacokinetic behavior in vivo. Herein, the advanced bioanalysis for tracing the in vivo fate of NDDSs is summarized, including liquid chromatography tandem-mass spectrometry (LC-MS/MS), Förster resonance energy transfer (FRET), aggregation-caused quenching (ACQ) fluorophore, aggregation-induced emission (AIE) fluorophores, enzyme-linked immunosorbent assay (ELISA), magnetic resonance imaging (MRI), radiolabeling, fluorescence spectroscopy, laser ablation inductively coupled plasma MS (LA-ICP-MS), and size-exclusion chromatography (SEC). Based on these technologies, a comprehensive survey of monitoring the dynamic changes of NDDSs in structure, composition and existing form in system (i.e. carrier polymers, released and encapsulated drug) with recent progress is provided. We hope that this review will be helpful in appropriate application methodology for investigating the pharmacokinetics and evaluating the efficacy and safety profiles of NDDSs.

Effect of Carrier Lipophilicity and Preparation Method on the Properties of Andrographolide⁻Solid Dispersion

Solid dispersion (SD) is a useful approach to improve the dissolution rate and bioavailability of poorly water-soluble drugs. This work investigated the effects of carrier material lipophilicity and preparation method on the properties of andrographolide (AG)–SD. The SDs of AG and the carrier materials, polyethylene glycol (PEG) and PEG grafted with carbon chains of different length (grafted PEG), have been prepared by spray-drying and vacuum-drying methods. In AG–SDs prepared by the different preparation methods with the same polymer as carrier material, the intermolecular interaction, 5% weight-loss temperature, the melting temperature (T_m), surface morphology, crystallinity, and dissolution behavior have significant differences. In the AG–SDs prepared by the same spray-drying method with different grafted PEG as carrier material, T_m, surface morphology, crystallinity, and dissolution behavior had little difference. In the AG–SDs prepared by the same vacuum-drying method with different grafted PEG as carrier material, the crystallinity and T_m decreased, and the dissolution rate of AG increased with the increase of grafted PEG lipophilicity. The preparation method has an important effect on the properties of SD. The increase of carrier material lipophilicity is beneficial to the thermal stability of SD, the decrease of crystallinity and the increase of dissolution rate of a poorly water-soluble drug in the SD.

Entecavir-loaded poly (lactic-co-glycolic acid) microspheres for long-term therapy of chronic hepatitis-B: Preparation and in vitro and in vivo evaluation

To avoid severe exacerbations in the load of hepatitis B virus (HBV) as a consequence of discontinuous use of anti-HBV drugs, entecavir (ETV), the first-line anti-HBV drug, was primally formulated as extended-release poly (lactic-co-glycolic acid) microspheres in the present study. Because ETV is slightly soluble in water and in some other organic solvents used for microsphere preparation, methods for solid-microencapsulation were employed to fabricate the ETV microspheres. The optimized microspheres were evaluated for their morphology, particle size, drug loading, in vitro drug release, and in vivo pharmacokinetics in rats. The optimized formulation was found to have a mean particle size of 86 µm and drug loading of 13%. Differential scanning calorimetry and powder X-ray diffraction indicated that ETV existed in crystal, amorphous, and molecular states in the microspheres. In vitro and in vivo release revealed that the dissolution of ETV dominated the release process. The morphology of the microspheres and changes in the morphology during in vitro release were assessed by scanning electron microscopy. The novel ETV-MS described in this study should have great potential for clinical use as an alternative treatment against HBV.

Electrospun PLGA membrane incorporated with andrographolide-loaded mesoporous silica nanoparticles for sustained antibacterial wound dressing

Aim: To assess the wound-healing ability of poly(lactic-co-glycolic acid) (PLGA) nanofibrous wound dressing incorporated with andrographolide (Andro)-loaded mesoporous silica nanoparticles (MSNs). Materials & methods: PLGA/Andro-MSNs nanofibrous membrane wound dressings were produced by electrospinning. The effects of MSNs on the hydrophilicity, degradation and mechanical strength of membranes were evaluated. The cumulative release of Andro in vitro was obtained. Cell culture and in vivo tests on infectious models were carried out. Results: The PLGA/Andro-MSNs membrane showed a sustained release of Andro. The incorporation of MSNs into PLGA improved the hydrophilicity of the nanofibrous membranes. Cell culture and in vivo tests showed that PLGA/Andro-MSNs membrane can promote epidermal cell adhesion and reduce inflammation process. Conclusion: PLGA/Andro-MSNs nanofibrous membrane exhibited an efficient wound-healing ability.

A complex micellar system co-delivering curcumin with doxorubicin against cardiotoxicity and tumor growth

Background

Dose-dependent irreversible cardiac toxicity of doxorubicin (DOX) becomes a major obstacle for the clinical use. Nowadays much attention is being paid to combination therapy with DOX and antioxidant agents, which would improve the clinical efficacy by protecting from cardiotoxicity along with the maintained performance as an antitumor drug. With the assistance of nanoscience and polymer engineering, herein a complex polymeric micellar system was developed for co-loading DOX and a premium natural antioxidant curcumin (CUR), and we investigated whether this new formulation for DOX delivery could achieve such a goal.

Methods

The dually loaded micelles co-encapsulating DOX and CUR (CPMDC) were prepared through thin-film rehydration by using the amphiphilic diblock copolymer monomethoxy poly(ethylene glycol) (mPEG)–poly(ε-caprolactone) (PCL)–N-t-butoxycarbonyl-phenylalanine (BP) synthesized by end-group modification of mPEG–PCL with BP. Quantitative analysis was conducted by HPLC methods for drugs in micelles or biosamples. Molecular dynamics simulation was performed using HyperChem software to illustrate interactions among copolymer and active pharmaceutical ingredients. The safety and antitumor efficacy were evaluated by in vitro viability of H9C2 cells, and tumor growth inhibition in tumor-bearing mice respectively. The protection effects against DOX-induced cardiotoxicity were investigated according to several physiological, histopathological and biochemical markers concerning systemic and cardiac toxicity.

Results

CPMDC were obtained with favorable physicochemical properties meeting the clinical demand, including uniform particle size, fairly high encapsulation efficiency and drug loadings, as well as good drug release profiles and colloidal stability. The result from molecular dynamics simulation indicated a great impact of the interactions among copolymer and small molecules on the ratiometrical co-encapsulation of both drugs. MTT assay of in vitro H9C2 cells viability demonstrated good safety of the CPMDC formulation, which also showed definite signs of decrease in xenograft tumor growth. The studies on pharmacokinetics and tissue distribution further revealed that DOX delivered by CPMDC could result in prolonged systemic circulation and increased DOX accumulation in tumor but decreased level of the toxic metabolite doxorubicinol in heart tissue compared to free DOX alone or the cocktail combination.

Conclusion

The findings from present study substantiated that such a complex micellar system codelivering DOX with CUR does produce the effect of killing two birds with one stone via distinctive nanocarrier-modified drug-drug interactions.

Studies on Core-Shell Nanocapsules of Felodipine: In Vitro-In Vivo Evaluations

The present study aimed for in vitro-in vivo-in silico simulation studies of experimentally designed (3²-factorial) Capmul PG-8-cored, Eudragit RSPO-Lutrol F 127 nanocapsules to ferry felodipine using GastroPlus™. The in silico parameter sensitivity analysis for pharmacokinetic parameters was initially assessed to justify the preparation of felodipine-loaded nanocapsules (FLNs) with enhanced solubility to overcome the bioavailability issues of felodipine. The overall integrated desirability ranged between 0.8187 and 0.9488 for three optimized FLNs when analyzed for mean particle size, zeta potential, encapsulation efficiency, and in vitro dissolution parameters. The morphological evaluation (SEM, TEM, and AFM) demonstrated spherical nanoparticles (200-300 nm). Validated LC-MS/MS analysis demonstrated enhanced relative bioavailability (13.37-fold) of optimized FLN as compared to suspension. The simulated regional absorption of the FLN presented significant absorption from the cecum (26.3%) and ascending colon (20.1%) with overall absorption of 67.4% from the GIT tract. Furthermore, in vitro-in vivo correlation demonstrated the Wagner-Nelson method as the preferred model as compared to mechanistic and numerical deconvolution on the basis of least mean absolute prediction error, least standard error of prediction, least mean absolute error, and maximum correlation coefficient (r ² = 0.920). The study demonstrated enhanced oral absorption of felodipine-loaded nanocapsules, and GastroPlus™ was found to be an efficient simulation tool for in vitro-in vivo-in silico simulations.

Spermidine-mediated poly(lactic-co-glycolic acid) nanoparticles containing fluorofenidone for the treatment of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis is a progressive, fatal lung disease with poor survival. The advances made in deciphering this disease have led to the approval of different antifibrotic molecules, such as pirfenidone and nintedanib. An increasing number of studies with particles (liposomes, nanoparticles [NPs], microspheres, nanopolymersomes, and nanoliposomes) modified with different functional groups have demonstrated improvement in lung-targeted drug delivery. In the present study, we prepared, characterized, and evaluated spermidine (Spd)-modified poly(lactic-co-glycolic acid) (PLGA) NPs as carriers for fluorofenidone (AKF) to improve the antifibrotic efficacy of this drug in the lung. Spd-AKF-PLGA NPs were prepared and functionalized by modified solvent evaporation with Spd and polyethylene glycol (PEG)-PLGA groups. The size of Spd-AKF-PLGA NPs was 172.5±4.3 nm. AKF release from NPs was shown to fit the Higuchi model. A549 cellular uptake of an Spd-coumarin (Cou)-6-PLGA NP group was found to be almost twice as high as that of the Cou-6-PLGA NP group. Free Spd and difluoromethylornithine (DFMO) were preincubated in A549 cells to prove uptake of Spd-Cou-6-PLGA NPs via a polyamine-transport system. As a result, the uptake of Spd-Cou-6-PLGA NPs significantly decreased with increased Spd concentrations in incubation. At higher Spd concentrations of 50 and 500 µM, uptake of Spd-Cou-6-PLGA NPs reduced 0.34- and 0.49-fold from that without Spd pretreatment. After pretreatment with DFMO for 36 hours, cellular uptake of Spd-Cou-6-PLGA NPs reached 1.26-fold compared to the untreated DFMO group. In a biodistribution study, the drug-targeting index of Spd-AKF-PLGA NPs in the lung was 3.62- and 4.66-fold that of AKF-PLGA NPs and AKF solution, respectively. This suggested that Spd-AKF-PLGA NPs accumulated effectively in the lung. Lung-histopathology changes and collagen deposition were observed by H&E staining and Masson staining in an efficacy study. In the Spd-AKF-PLGA NP group, damage was further improved compared to the AKF-PLGA NP group and AKF-solution group. The results indicated that Spd-AKF-PLGA NPs are able to be effective nanocarriers for anti-pulmonary fibrosis therapy.

A reformative shear precipitation procedure for the fabrication of vancomycin-loaded poly(lactide-co-glycolide) microspheres

This study reports the encapsulation of vancomycin, as a model hydrophilic drug, into poly(lactide-co-glycolide) microspheres using a novel reformative shear precipitation procedure. In contrast to the external aqueous phase used in the conventional microencapsulation technique based on emulsion solvent evaporation/extraction, the reformative shear precipitation procedure explored in this study uses a shear medium composed of glycerol as the viscous medium and ethanol as polymer antisolvent, which is relatively immiscible with the hydrophilic drug. This limits drug diffusion and leads to rapid microsphere solidification, which allows a large proportion of the hydrophilic drug to be encapsulated within the microspheres. The influence of various processing parameters, including polymer concentration, volume ratio of ethanol to glycerol in the shear medium, volume of aqueous drug solution, initial drug loading, and injecting rate of the drug-polymer emulsion, on the encapsulation efficiency and characteristics of resulting microspheres were investigated. The morphology and release characteristics, as well as mechanical, in vitro and in vivo behaviour of vancomycin-loaded poly(lactide-co-glycolide) microspheres prepared using the novel procedure were also investigated. The results demonstrated that the reformative shear precipitation procedure could achieve the loading of hydrophilic drugs into poly(lactide-co-glycolide) microspheres with high encapsulation efficiency, and the success of the procedure was largely influenced by the volume ratio of ethanol to glycerol in the shear medium. Vancomycin-loaded poly(lactide-co-glycolide) microspheres prepared using this procedure demonstrated favourable mechanical characteristics, antibacterial activity, and in vivo degradation behaviour which suggested their suitability for use as a sustained delivery system.

A quality by design approach on polymeric nanocarrier delivery of gefitinib: formulation, in vitro, and in vivo characterization

Gefitinib is an anticancer agent which acts by inhibiting epidermal growth factor receptor tyrosine kinase receptors. The aim of the present study was to prepare gefitinib nanosuspension. Gefitinib was encapsulated in Eudragit^® RL100 and then dispersed in stabilizer solution, polyvinyl alcohol, and polyvinylpyrrolidone K30. Nanosuspension was prepared by using homogenization and ultrasonication techniques. The quality by design approach was also used in the study to understand the effect of critical material attributes (CMAs) and critical processing parameters (CPPs) on critical quality attributes and to improve the quality and safety of formulation. To study the effect of CMAs and CPPs, 2³ full factorial design was applied. The particle size, polydispersity index, and zeta potential of the optimized solution were 248.20 nm, 0.391, and -5.62 mV, respectively. Drug content of the optimized nanoformulation was found to be 87.74%±1.19%. Atomic force microscopy studies of the optimized formulation confirmed that the prepared nanoparticles are smooth and spherical in nature. In vitro cytotoxicity studies of the nanosuspension on Vero cell line revealed that the formulation is nontoxic. The gefitinib nanosuspension released 60.03%±4.09% drug over a period of 84 h, whereas standard drug dispersion released only 10.39%±3.37% drug in the same duration. From the pharmacokinetic studies, half-life, C_max, and T_max of the drug of an optimized nanosuspension were found to be 8.65±1.99 h, 46,211.04±5,805.97 ng/mL, and 6.67±1.77 h, respectively. A 1.812-fold increase in relative bioavailability of nanosuspension was found, which confirmed that the present formulation is suitable to enhance the oral bioavailability of gefitinib.

Strategies for formulation development of andrographolide

This review is the comprehensive account of the pharmaceutical aspects of andrographolide with special emphasis on its delivery that have take place over the century.

Nanonization of andrographolide by a wet milling method: the effects of vitamin E TPGS and oral bioavailability enhancement

Andrographolide (AND) has wide prospects in clinical use, but suffers from the restriction of poor oral bioavailability, due to its low solubility, rapid and extensive metabolism and efflux by P-glycoprotein (P-gp).

Preparation, characterization, in vivo pharmacokinetics, and biodistribution of polymeric micellar dimethoxycurcumin for tumor targeting

Dimethoxycurcumin (DMC) is an analog of curcumin with superior efficacy in various disease models. Currently, drug delivery system research on DMC is very limited, and it has become a huge challenge to realize further developments and clinical applications. In the present study, a kind of amphiphilic block copolymer, N-t-butoxycarbonyl-phenylalanine terminated monomethoxyl poly (ethylene glycol)-b-poly (ε-caprolactone), or mPEG-PCL-Phe(Boc), was prepared from monomethoxyl poly (ethylene glycol)-b-poly (ε-caprolactone) (mPEG-PCL) with its hydroxyl terminal chemically converted into N-t-butoxycarbonyl-phenylalanine (Boc-Phe). This copolymer was determined to have a fairly low critical micelle concentration (2.56×10⁻³ mg/mL) and passive targeting potential to tumor tissue, and thus was applied to develop a polymeric micellar formulation of DMC for the first time. The DMC-loaded micelles prepared by thin-film hydration method had typical shell–core structure, with an average particle size of 17.9±0.4 nm and a polydispersity index of 0.045±0.011. The drug loading capacity and entrapment efficiency were 9.94%±0.15% and 97.22%±0.18%, respectively, indicating a high-affinity interaction between DMC and the copolymer. At a concentration of 2 mg/mL, the reconstituted micelle solution could be maintained for at least 10 days at room temperature, and displayed a low initial burst release followed by a sustained release in vitro. Pharmacokinetic study in rats revealed that in vivo drug exposure of DMC was significantly increased and prolonged by intravenously administering DMC-loaded micelles when compared with the same dose of free DMC dissolved in dimethyl sulfoxide. Furthermore, in vivo distribution results from tumor-bearing nude mice demonstrated that this micellar formulation significantly changed the biodistribution profile of DMC and increased drug accumulation in tumors. Therefore, the polymeric micellar formulation of DMC, based on the amphiphilic block copolymer, mPEG-PCL-Phe(Boc), could provide a desirable method for delivering DMC, especially for applications in cancer therapy.

A Uniform Ultra-Small Microsphere/SAIB Hybrid Depot with Low Burst Release for Long-Term Continuous Drug Release

PURPOSE

In the present study, a uniform ultra-small microsphere/sucrose acetate isobutyrate (SAIB) hybrid depot (m-SAIB depot) was designed to provide a long-term sustained release drug delivery system which not only reduced the burst release of an SAIB depot, but also eliminated the lag-time of PLGA microspheres.

METHODS

Risperidone loaded m-SAIB depot (Ris-m-SAIB depot) was characterized by in vitro drug release, pharmacokinetics, in vivo degradation and biocompatibility, in comparison with risperidone loaded SAIB depot (Ris-SAIB depot).

RESULTS

Ris-m-SAIB depot showed a low burst release (0.64%) and a reduced in vitro drug release rate due to the encapsulation of most drug in microspheres. After intramuscular administration, the in vivo burst release of Ris-m-SAIB was significantly decreased, as reflected by the low Cmax/Cs(4-td) (approximately 30-fold reduction), in comparison with Ris-SAIB depot. From 4 to 78 days, Ris-m-SAIB depot showed a higher plasma drug level (1.55 ~ 16.30 ng/ml) with a steadier drug release profile compared with Ris-SAIB depot. Ris-m-SAIB depot degraded gradually with a degradation t1/2 of 54.6 days and exhibited good biocompatibility in vivo.

CONCLUSION

These results demonstrate the potential application of a uniform ultra-small microsphere/SAIB hybrid depot for continuously delivering small drug molecules for long periods of time without burst release.

Rationally developed core–shell polymeric-lipid hybrid nanoparticles as a delivery vehicle for cromolyn sodium: implications of lipid envelop on in vitro and in vivo behaviour of nanoparticles upon oral administration

In the present study, cromolyn sodium, a highly water soluble molecule was encapsulated into rationally designed, core–shell polymeric-lipid hybrid nanoparticles for enhancing its oral bioavailability, by improving its intestinal permeability.