Hybrid lipid core chitosan-TPGS shell nanocomposites as a promising integrated nanoplatform for enhanced oral delivery of sulpiride in depressive disorder therapy.

Sulpiride (SUL), a benzamide derivative, acts as a multitarget drug with extensive biological properties. However, being a P-glycoprotein efflux substrate with a limited oral bioavailability imposes a challenge to its clinical efficacy. The current research explores the impact of tailored hybrid lipid-polysaccharide nanocomposites in augmenting the biological performance of SUL. Chitosan-graft-tocopherol polyethylene glycol 1000 succinate (TPGS) copolymers were synthesized and integrated as a polysaccharide shell into a SUL-loaded lipid nanocore. The optimized nanohybrids revealed a nanocore-shell structure with 110.1 nm particle size, 23.7 mV zeta potential, 85.42% encapsulation efficiency, a pH-dependent-release profile, and an acceptable mucoadhesive tendency. Employing TPGS into the chitosan backbone alleviated the cellular internalization of nanohybrids into the Caco-2 intestinal cells and hence increased the intestinal permeation and the oral bioavailability of SUL by 3.3, and 8.7-folds, respectively. Reserpine-induced depression rat model confirmed the superior antidepressant activity of nanohybrids, compared with free SUL and a marketed product. The nanohybrids exhibited 1.87- and 1.47-folds enhancement in both serotonin and dopamine levels, respectively. Additionally, nanohybrids were shown to attenuate brain oxidative stress state and SUL irritant effect on different body tissues. Overall, the newly tailored nanohybrids pave the way for an advance in the field of oral drug delivery.

Potential Privilege of Maltodextrin-α-Tocopherol Nano-Micelles in Seizing Tacrolimus Renal Toxicity, Managing Rheumatoid Arthritis and Accelerating Bone Regeneration.

BACKGROUND: Tacrolimus (TAC) is a powerful immunosuppressive agent whose therapeutic applicability is confined owing to its systemic side effects. OBJECTIVE: Herein, we harnessed a natural polymer based bioconjugate composed of maltodextrin and α-tocopherol (MD-α-TOC) to encapsulate TAC as an attempt to overcome its biological limitations while enhancing its therapeutic anti-rheumatic efficacy. METHODS: The designed TAC loaded maltodextrin-α-tocopherol nano-micelles (TAC@MD-α-TOC) were assessed for their physical properties, safety, toxicological behavior, their ability to combat arthritis and assist bone/cartilage formation. RESULTS: In vitro cell viability assay revealed enhanced safety profile of optimized TAC@MD-α-TOC with 1.6- to 2-fold increase in Vero cells viability compared with free TAC. Subacute toxicity study demonstrated a diminished nephro- and hepato-toxicity accompanied with optimized TAC@MD-α-TOC. TAC@MD-α-TOC also showed significantly enhanced anti-arthritic activity compared with free TAC, as reflected by improved clinical scores and decreased IL-6 and TNF-α levels in serum and synovial fluids. Unique bone formation criteria were proved with TAC@MD-α-TOC by elevated serum and synovial fluid levels of osteocalcin and osteopontin mRNA and proteins expression. Chondrogenic differentiation abilities of TAC@MD-α-TOC were proved by increased serum and synovial fluid levels of SOX9 mRNA and protein expression. CONCLUSION: Overall, our designed bioconjugate micelles offered an excellent approach for improved TAC safety profile with enhanced anti-arthritic activity and unique bone formation characteristics.

Precisely Fabricated Sulpiride-Loaded Nanolipospheres with Ameliorated Oral Bioavailability and Antidepressant Activity.

BACKGROUND: Sulpiride (SUL), is a selective antidopaminergic drug that had extensive biological activities. However, its sparingly aqueous solubility and limited gastrointestinal permeability lead to scanty oral bioavailability which hinders its clinical efficacy. OBJECTIVE: SUL-loaded lipospheres (SUL-LPS) were designed to serve as an oral biocompatible nanovector for improving SUL permeability as well as conquering its low oral absorption and then in turn enhancing its antidepressant action. METHODS: SUL-LPS were fabricated via two processing techniques namely, melt emulsification and solvent evaporation. The impact of different lipid cores, phospholipid shells together with various surfactant concentrations and types on the lipospheres properties were screened. Detailed physicochemical elucidations were performed followed by ex vivo permeation appraisal using the non-everted intestine model. The pharmacokinetic parameters of SUL-LPS, free SUL and marketed product were assessed following oral administration to healthy rats. Reserpine-induced depression rat model was used to assess the antidepressant action of SUL-LPS on which full behavioural and biochemical analysis was conducted. Safety attributes of nanoencapsulated SUL on the brain and other internal organs were evaluated. RESULTS: The optimum LPS revealed an excellent nanosize with a narrow PdI, negative zeta potential and acceptable entrapment efficiency of 68.62 nm, 0.242, -30.4 mV and 84.12%, respectively. SUL-LPS showed a sustained release pattern and 2.1-fold enhancement in the intestinal permeation parameters with low mucin interaction. Oral pharmacokinetic appraisal exhibited that LPS provided 3.4-fold improvement in SUL oral bioavailability together with long-circulating properties, relative to the free drug. Pharmacodynamic study confirmed the superior antidepressant action of SUL-LPS as evident by 1.6 and 1.25-fold elevation in the serotonin and dopamine expressions, respectively. Meanwhile, nanotoxicological appraisal proved the biocompatibility of SUL-LPS upon repetitive oral administration. CONCLUSION: Rationally designed lipospheres hold promising in vitro and in vivo characteristics for efficient delivery of SUL with high oral bioavailability, antidepressant activity together with a good safety profile.

Graphene oxide crosslinked-zein nanofibrous scaffolds for prominent Cu-adsorption as tissue regeneration promoters in diabetic rats: Nanofibers optimization and in vivo assessment.

Diabetic ulcers are prone to bacterial contamination and can severely affect patient's quality of life. This study is first report to explore copper-grafted graphene oxide-crosslinked zein scaffolds (Cu-GZS) for promoting cutaneous excision wounds healing as a promising therapeutic modality in diabetic male-rats. Cu-GZS scaffolds were fabricated using electrospinning technique, where GO was employed as an echo-friendly crosslinker to meliorate mechanical stability and swellability of scaffolds. To circumvent risk of infection, copper ions were grafted into GZS as bactericidal agents and angiogenesis promoters, through soaking GZS nanofibers into Cu-solution or direct loading during electrospinning process. SEM images showed GO encapsulation by wrapping around/or trapping within nanofibrous. Interestingly, formation of chemical amide bond between zein and GO was proven by FTIR spectra. Crosslinking of zein nanofibers with GO increased tensile strength of nanofibrous by 3-folds compared to uncrosslinked zein nanofibers. Optimized Cu-GZS exhibited constant release rate of copper over a period of 8 days (~53.42%). Cu-GZS immensely accelerated wound closure demonstrated by diminished infiltration of leukocytes, absence of α-SMA positive cells, presence of fully intact epithelium with normal keratinization and accelerated wound size reduction, compared to control. Cu-GZS scaffolds could serve as promising biomaterials for effective topical wound healing in diabetic rats.

Selenium: A sole treatment for erosive oral lichen planus (Randomized controlled clinical trial).

Oral lichen planus (OLP) is a chronic disease with immune-mediated pathogenesis. Selenium (Se), an antioxidant, plays a role in modulating immunity. The aim of this clinical trial was to evaluate two Se forms (novel topical hydrogel and oral capsules), solely, in treating erosive OLP based on clinical evaluation and salivary oxidative stress markers. Patients were allocated into one of three groups: group I, topical corticosteroids; group II, topical Se; and group III, systemic Se. Treatment lasted for 6 weeks; patients were clinically evaluated at baseline, 6, and 12 weeks. Biochemical analysis for salivary malondialdehyde (MDA) and total antioxidant capacity (TAC) levels at baseline and 6 weeks was performed. There was a significant reduction in signs and symptoms in response to all treatment modalities. However, there was no significant difference among the three groups at 6 weeks. At 12 weeks, group II had significantly lower pain scores compared with group I. Salivary MDA levels showed a significant decrease in patients of group I and group III. TAC levels showed no significant difference in response to treatment. Selenium can be proposed as a treatment for OLP. Salivary MDA levels can be a biomarker for OLP disease severity.

α-Bisabolol-Loaded Cross-Linked Zein Nanofibrous 3D-Scaffolds For Accelerating Wound Healing And Tissue Regeneration In Rats.

OBJECTIVES: Novel α-bisabolol (BIS)-loaded citric acid cross-linked zein nanofibrous scaffolds (C-ZNFs) were proposed to serve as safe platforms for promoting wound repair in rats. METHODS: ZNFs were synthesized using electrospinning technique, then NFs, with adequate water resistance, were produced using citric acid as a safe cross-linker. RESULTS: Compared to the uncross-linked ZNFs, cross-linking with 7% w/w citric acid decreased swelling index by 3 folds, while the tensile strength and the contact angle were enhanced to 2.5 and 3.8 folds, respectively. SEM images showed beads-free homogeneous NFs with a fully inter-connected 3D-network, where the average diameter of optimized C-ZNFs was 181.7±50 nm. After 24 h, C-ZNFs exhibited a decreased BIS release rate (45.6%), compared to uncross-linked mats (84.9%). By increasing BIS concentration, the cell adhesion (WI38 fibroblasts) was improved which can be attributed mainly to BIS activation of transforming growth factor-beta (TGF-ß1). The MTT-OD obtained values indicated that all tested zein scaffolds significantly enhanced the viability of WI38 fibroblasts, compared to the control after 48h of incubation which can be referred to the proliferative potential of zein by provoking cell spreading process. The scratch wound assay demonstrated that BIS-loaded ZNF scaffolds showed accelerated migration and proliferation of fibroblasts expressed by significantly higher wound closure rates compared to the control sample. BIS-loaded-C-ZNFs prominently accelerated tissue regeneration for wound closure demonstrated by entirely grown epithelium with normal keratinization and rapid wound contraction, compared to the control. Immunohistochemical results confirmed the superiority of BIS-loaded-C-ZNFs, where the observed reduced NF-κB and the elevated cytokeratin expressions confirmed the anti-inflammatory and proliferative effects of the scaffolds, respectively. CONCLUSION: In-vitro, optimized C-ZNFs offered a satisfactory cytocompatibility, adhesion and healing which were consistent with the in-vivo results. BIS-loaded-C-ZNFs could be regarded as a promising and effective biomaterial for tissue regeneration and for accelerating the wound healing process.

The usefulness of Veno-Arterial Extracorporeal Membranous Oxygenation in Patients with Cardiogenic Shock.

BACKGROUND: Venoarterial extracorporeal membranous oxygenation is a form of temporary mechanical circulatory support that gets as a salvage technique in patients with cardiogenic shock, we intended to evaluate the effect of (VA ECMO) support on hemodynamics and lactate levels in patients with cardiogenic shock. AIM: The aim of our study is to detect the ability to introduce veno-arterial extracorporeal membranous oxygenation (VA ECMO) as a temporary extracorporeal life support system (ECLS) in our unit, demonstrate the role of ECMO in cardiogenic shock patients regarding improving hemodynamics and microcirculation, and demonstrate the complications and drawbacks in our first center experience regarding VA ECMO. MATERIAL AND METHODS: This was a single-centre observational study that included 10 patients admitted with cardiogenic shock for which VA ECMO was used as mechanical circulatory support. RESULTS: The MAP increased after initiation of the support. It was 41.8 ± 9.3 mmHg and 59.5 ± 6.8 mmHg (P = 0.005). The use of VA ECMO support was associated with a statistically significant decrease in the base deficit (-10.6 ± 4.2 and -6.3 ± 7.4, P = 0.038). The serum lactate declined from 5.9 ± 3.5 mmoL/L to 0.6 ± 4.4 mmoL/L by the use of VA ECMO; a statistically significant change (P = 0.005). CONCLUSIONS: We concluded that VA ECMO as mechanical support for patients with cardiogenic shock might improve mean arterial blood pressure, base deficit and lactate clearance.

The anti-inflammatory effect of locally delivered nano-doxycycline gel in therapy of chronic periodontitis.

BACKGROUND AND OBJECTIVE: To date, various drugs as host modulating agents had been suggested as adjunctive treatment modality in the therapy of chronic periodontal disease. In this study, the anti-inflammatory effect of subgingivally delivered nanostructured doxycycline gel (nDOX) was evaluated and compared to conventional doxycycline gel (DOX) used as adjunct to scaling and root planning (SRP) in the treatment of moderate chronic periodontitis to reduce probing pocket depth. MATERIAL AND METHODS: Nanostructured doxycycline gel (nDOX) was prepared using spray-drying technique with chitosan (CH) as a matrix polymer, followed by dispersion in polyvinyl alcohol (PVA). The deepest periodontal pocket in 45 patients suffering from moderate chronic periodontitis was selected. The patients were divided into three groups following scaling and root planning (SRP); group I: SRP + nDOX, group II: SRP + DOX and group III: SRP + placeboCH. Plaque Index (PI), Gingival Index (GI), pocket depth (PD) and clinical attachment level(CAL), as well as ginigival crevicular fluid levels of (GCF) IL-6 and TNF-α were assessed at baseline, 1 and 3 months following local drug application. RESULTS: Group I showed significant reduction in probing depth and attachment gain compared with group II and III at one and three months period. The inflammatory mediators levels were significantly reduced in all treatment groups at one-month period. Except for group I, the reduced values were observed at three-month period. CONCLUSION: The results suggest that treatment with nDOX gel as an adjunct to SRP had anti-inflammatory effect by improving both clinical parameters and inflammatory markers up to three months period.

Hybrid polymeric matrices for oral modified release of Desvenlafaxine succinate tablets.

Purpose: Desvenlafaxine succinate (DSV) is a water soluble anti-depressant drug, which is rapidly absorbed after oral administration exaggerating its side effects. The current work aimed to prepare controllable release DSV matrix to reduce DSV side effects related to its initial burst. Methods: Fifteen DSV matrix formulations were prepared using different polymers, polymer/drug ratios and matrix excipients and characterized using Differential Scanning Calorimetry (DSC), infrared (IR) spectroscopy, water uptake and in vitro DSV release. The release kinetics were calculated to determine the drug release mechanism. Ex-vivo DSV absorption via rat intestinal mucosal cells and the calculation of the apparent permeability coefficient (Papp) were performed using everted sac technique. Results: Maltodextrin was the best matrix excipient (F7 and F10) showing acceptable decrease in the initial burst compared to the innovator. The addition of negatively charged polymers sodium carboxy methyl cellulose (SCMC) or sodium alginate resulted in an interaction that was proved by DSC and IR findings. This interaction slowed DSV release. F10 showed an excellent absorption of more than 80% of DSV after 4 h and the highest similarity factor with the innovator (84.7). Conclusion: A controllable release pattern of DSV was achieved using Methocel, Maltodextrin and SCMC. The obtained results could be used as a platform to control the release of cationic water soluble drugs that suffer from side effects associated with their initial burst after oral administration.

A Multi-layered Particulate System for Desvenlafaxine Succinate Oral Customized Release.

BACKGROUND: With its reported side effects Desvenlafaxine succinate (DSV) is a good candidate to prepare prolonged release system. Such prolonged release could decrease the rapid DSV absorption after oral administration and reduce its exaggerated side effects. METHODS: A prolonged release Desvenlafaxine succinate (DSV) multilayered system was prepared by ionotropic gelation using sodium alginate (SA) and calcium chloride as a cross-linker. DSV was incorporated simultaneously during the gelation stage and the formed beads were evaluated for shape and particle size. Thirteen formulation variables including pH, DSV: polymer ratio, cross-linker concentration and curing time were optimized for optimal drug entrapment. The optimized formula was evaluated ex vivo using the everted sac technique to predict DSV absorption through intestinal mucosal cells, follow the permeation and calculate its apparent permeability coefficient. RESULTS: The optimum formulation variables were: pH (8-9), DSV: SA ratio (2:1), cross-linker concentration (5%w/v) and 30 min curing time. Multilayered beads coating using chitosan and SA was compared with uncoated beads or the innovator for DSV release. Coating of the beads greatly retarded DSV release with a release profile similar to that of the innovator. An optimized formula (T13) coated with 0.04% w/v of each of chitosan and SA was selected. The developed system gave rise to a prolonged release pattern with high similarity factor with the innovator. CONCLUSION: The results of the current work can be applied to prepare controlled release systems of similar drugs that have intense side effects associated with their initial burst after oral administration.

Left ventricular scar impact on left ventricular synchronization parameters and outcomes of cardiac resynchronization therapy.

BACKGROUND: Left ventricular scar, including global scar and lateral wall, plays an important role in predicting response to cardiac resynchronization therapy (CRT). MATERIALS AND METHODS: Thirty patients underwent CRT implantation. Assessment of left ventricular (LV) dyssynchrony was done through Gated SPECT LV phase analysis. Pre-implantation cardiac magnetic resonance (CMR) with late gadolinium enhancement technique to examine LV scar burden. Echocardiographic examination of LV end-systolic volume (LVES) prior to CRT and 6 months later. RESULTS: Thirty patients received CRT (mean age 58.7±9.0, 24 males). Reverse LV remodeling (decline ≥15% from baseline VES) was documented in 19 patients. Temporal changes in LV dyssynchrony parameters were correlated to LV reverse remodeling. Applying ROC for predicting CRT non-response showed a cutoff 36.5% of global LV scar burden had a sensitivity of 81.8% and specificity of 68.4%. A cutoff for lateral wall scar burden 40.5% of whole lateral wall had a sensitivity of 72.7% and specificity of 68.4%. CONCLUSION: Reverse LV remodeling is associated with temporal improvements in LV dyssynchrony parameters. LV scar had an unfavorable impact on CRT response. Both global and lateral wall scar burden could predict CRT nonresponse status.

Enhanced Periodontal Regeneration by Novel Single Application Sustained Release Nano-Structured Doxycycline Films.

The use of different drug classes as host modulating agents has been postulated to have significance as an adjunctive remedy curing chronic periodontitis. In this study nano-structured films containing doxycyclin (DOX) were evaluated for such purpose. Nano DOX/chitosan particulate system was prepared using spray drying technique and was then incorporated in PVA-based films. The particles were evaluated for particle size, zeta potential and possible drug/polymer interaction. The films were also tested for in-vitro drug release and clinical efficacy compared with placebo and DOX-loaded films. The formed particles had a zeta potential of + 13.8 mV and particle size of 52.86 nm with a polydispersity of PDI=0.946. No significant drug/polymer interaction was detected by DSC thermal analysis. In-vitro DOX release was sustained for about a week with the nano-structured films showing 23% of the drug released compared with 44% released from DOX films. Clinical efficacy was done on 150 periodontal pockets from patients suffering from moderate chronic periodontitis. Following scaling and root planning they were divided into three groups; group I receiving nano-structured (DOX), group II receiving DOX and group III receiving placebo films. Evaluation was done both clinically and biochemically at base-line, 1 week, 1 month and 2 months following drug application. Clinical findings indicated a significant effect of both nano-structured and DOX films in improving the measured parameters compared with the control and placebo groups.

Swellable floating tablet based on spray-dried casein nanoparticles: Near-infrared spectral characterization and floating matrix evaluation.

In this study, spray-dried alfuzosin hydrochloride (ALF)-loaded casein (CAS) nanoparticles were successfully used for the preparation of a swellable floating matrix via direct compression. The developed NIR calibration model was able to assess ALF and CAS levels in five different batches of drug-loaded nanoparticles. The calibration and prediction plots exhibited good linearity with correlation coefficients of more than 0.9. The standard error of calibration and cross-validation was less than 5% of the measured values, confirming the accuracy of the model. A linear relationship was obtained correlating the actual drug entrapped and the predicted values obtained from the NIR partial least squares regression model. The un-crosslinked tablet demonstrated a substantial weight gain (317% after 2h) and completely disintegrated after 3-4h whereas both 10 and 40% w/w genipin-crosslinked tablets showed lower weight gain (114 and 42% after 2h, respectively). A rapid floating of the tablets within 5-15min (compared to 45min for the marketed tablet) was observed, with maintained floating for 24h. Marketed and prepared tablets succeeded to prolong ALF release for 24h. The development of drug-loaded CAS nanoparticles using spray-drying represents a new alternative for the preparation of swellable floating tablets for prolonged drug release.

Novel microstructured sildenafil dosage forms as wound healing promoters.

PURPOSE: Study the possible benefit of combining biodegradable polymers with sildenafil citrate (SC) in wound healing. METHOD: Biodegradable micronized powdered formulations of SC were prepared by spray drying using chitosan (P1) or chitosan/gum Arabic (P2). Powders were characterized by differential scanning calorimetry, Scanning electron microscope, particle size analysis, flow and swelling behavior. The powders were also incorporated into microstructured gels and in vitro SC release from powders and gels was tested. In vivo wound healing acceleration was tested by measuring area contraction of excision wounds and histologically. Post-healing tensile strength (TS) for incision wounds in rats receiving powder formulations was tested. RESULTS: The powders were in the micron-size range showing no SC-polymers interaction. Powders had poor flow with angle of repose (θ) of 41 - 48°, and high moisture uptake reaching 107% for placebo powder P1. Good excision wound healing was seen with P1 and G1 formulations showing 98.4 and 98.5% reduction in wound area, respectively, compared with 83% for the control. Incision wounds were improved with P1 showing TS value of 6.9 compared with 3.7 kg/cm² for control. Histological examinations supported. CONCLUSION: Spray-dried chitosan/SC powder (P1) and its gel form (G1) could be promising wound healing promoters as supported by the histological examinations.

Ionically-crosslinked milk protein nanoparticles as flutamide carriers for effective anticancer activity in prostate cancer-bearing rats.

In this study, casein (CAS) nanoparticles were used to encapsulate the hydrophobic anticancer drug, flutamide (FLT), aiming at controlling its release, enhancing its anti-tumor activity, and reducing its hepatotoxicity. The nanoparticles were prepared by emulsification of CAS, at pH below its isoelectric point, and stabilized via ionic-crosslinking with sodium tripolyphosphate (TPP). The nanoparticles were spherical and positively charged with a size below 100 nm and exhibited a sustained drug release up to 4 days. After intravenous administration into prostate cancer-bearing rats for 28 days, FLT-loaded CAS nanoparticles showed a higher anti-tumor efficacy as revealed by a significantly higher % reduction in PSA serum level (75%) compared to free FLT (55%). Moreover, the nanoparticles demonstrated a marked reduction in the relative weights of both prostate tumor and seminal vesicle (43% and 32%) compared to free FLT (12% and 18%), respectively. A significantly higher anti-proliferative, anti-angiogenic, and apoptotic effects was demonstrated by the nanoparticles compared to drug solution as evidenced by their ability to decrease the expression of the proliferative marker (Ki-67) and reduce the level of tumor angiogenic markers (VEGF and IGF-1) as well as their ability to activate caspase-3 with subsequent induction of apoptosis in prostate cancer cells. Conclusively, these novel ionically-crosslinked milk protein nanovehicles offer a promising carrier to allow controlled intravenous delivery of hydrophobic anticancer drugs.

Micellar delivery of flutamide via milk protein nanovehicles enhances its anti-tumor efficacy in androgen-dependent prostate cancer rat model.

PURPOSE: This article describes the preparation, physicochemical characterization and in vivo assessment of parenteral colloidal formulation of flutamide (FLT) based on biocompatible casein (CAS) self-assembled micelles in order to control drug release, enhance its antitumor efficacy and reduce its hepatotoxicity. METHODS: Spray-drying technique was successfully utilized to obtain solidified redispersible drug-loaded micelles. RESULTS: Spherical core-shell micelles were obtained with a particle size below 100 nm and a negative zeta potential above -30 mV exhibiting a sustained drug release up to 5 days. After intravenous administration into prostate cancer bearing rats for 28 days, FLT-loaded CAS micelles showed a higher antitumor efficacy as revealed by significantly higher reduction in PSA serum level (65.95%) compared to free FLT (55.43%). Moreover, micellar FLT demonstrated a marked decrease in relative weights of both prostate tumor and seminal vesicle (34.62 and 24.59%) compared to free FLT (11.86 and 17.74%), respectively. These antitumor responses were associated with notable reduction of cell proliferation, intratumoral angiogenesis and marked increase of tumor apoptosis. A significantly lower risk of hepatotoxicity was observed by micellar FLT as evidenced by lower alanine aminotransferase (ALT) serum level compared to free FLT. CONCLUSIONS: Overall this approach suggested that CAS micelles might be an ideal candidate for intravenous delivery of hydrophobic anticancer drugs.

Novel ionically crosslinked casein nanoparticles for flutamide delivery: formulation, characterization, and in vivo pharmacokinetics.

A novel particulate delivery matrix based on ionically crosslinked casein (CAS) nanoparticles was developed for controlled release of the poorly soluble anticancer drug flutamide (FLT). Nanoparticles were fabricated via oil-in-water emulsification then stabilized by ionic crosslinking of the positively charged CAS molecules below their isoelectric point, with the polyanionic crosslinker sodium tripolyphosphate. With the optimal preparation conditions, the drug loading and incorporation efficiency achieved were 8.73% and 64.55%, respectively. The nanoparticles exhibited a spherical shape with a size below 100 nm and a positive zeta potential (+7.54 to +17.3 mV). FLT was molecularly dispersed inside the nanoparticle protein matrix, as revealed by thermal analysis. The biodegradability of CAS nanoparticles in trypsin solution could be easily modulated by varying the sodium tripolyphosphate crosslinking density. A sustained release of FLT from CAS nanoparticles for up to 4 days was observed, depending on the crosslinking density. After intravenous administration of FLT-CAS nanoparticles into rats, CAS nanoparticles exhibited a longer circulation time and a markedly delayed blood clearance of FLT, with the half-life of FLT extended from 0.88 hours to 14.64 hours, compared with drug cosolvent. The results offer a promising method for tailoring biodegradable, drug-loaded CAS nanoparticles as controlled, long-circulating drug delivery systems of hydrophobic anticancer drugs in aqueous vehicles.

Spray-dried casein-based micelles as a vehicle for solubilization and controlled delivery of flutamide: formulation, characterization, and in vivo pharmacokinetics.

Novel casein (CAS)-based micelles loaded with the poorly soluble anti-cancer drug, flutamide (FLT), were successfully developed in a powdered form via spray-drying technique. Genipin (GNP) was used to crosslink CAS micelles as demonstrated by color variation of the micelles. Drug solubilization was enhanced by incorporation within the hydrophobic micellar core which was confirmed by solubility study and UV spectra. Spherical core-shell micelles were obtained with a particle size below 100 nm and zeta potential around -30 mV. At low drug loading, FLT was totally incorporated within micellar core as revealed by thermal analysis. However, at higher loading, excess non-incorporated drug at micelle surface caused a significant reduction in the surface charge density. Turbidity measurements demonstrated the high physical stability of micelles for 2 weeks dependent on GNP-crosslinking degree. In a dry powdered form, the micelles were stable for 6 months with no significant changes in drug content or particle size. A sustained drug release from CAS micelles up to 5 days was observed. After i.v. administration into rats, CAS micelles exhibited a prolonged plasma circulation of FLT compared to drug solution. Furthermore, a more prolonged drug systemic circulation was observed for GNP-crosslinked micelles. Overall, this study reports the application of spray-dried natural protein-based micelles for i.v. delivery of hydrophobic anti-cancer drugs such as FLT.

Novel spray-dried genipin-crosslinked casein nanoparticles for prolonged release of alfuzosin hydrochloride.

PURPOSE: To propose a simple method for the development of genipin-crosslinked casein micelles as a new delivery platform for prolonged release of alfuzosin hydrochloride. METHODS: Crosslinked casein micelles entrapping alfuzosin were transformed into solid redispersible nanoparticles via spray-drying technique with no need for drying adjuvants based on the stabilizing effect of casein. RESULTS: The nanoparticles displayed high production yields (86.99-94.63% w/w) with a reasonable drug incorporation efficiency ranged from 92.86 to 97.75%. The nanoparticles were readily reconstituted in aqueous solution with a particle size range of 122.1-260.0 nm and a zeta potential range of -21.6 to -36.6 mV indicating a good colloidal stability. No drug crystals were detectable in the scanning electron micrographs revealing successful encapsulation of alfuzosin into casein nanoparticles which was confirmed by differential scanning calorimetry. The nanoparticles succeeded in prolonging the drug release that could be controlled by modulating the genipin crosslinking degree. The release data showed a good fit into Higuchi release kinetics with non-Fickian type of drug diffusion. CONCLUSIONS: These results demonstrated that genipin-crosslinking combined with spray-drying technique could be used as a promising tool to develop solid redispersible casein nanoparticles with sustained drug release properties.