Fabrication and evaluation of valsartan-polymer- surfactant composite nanoparticles by using the supercritical antisolvent process

Investigation of the treatment potential of Raloxifene-loaded polymeric nanoparticles in osteoporosis: In-vitro and in-vivo analyses

Osteoporosis (OP), is a systemic bone disorder associated with low bone mass and bone tissue corrosion. Worsening of the disease condition leads to bone delicacy and fracture. Various drugs are available for the treatment of OP, however they have limitations including poor solubility, bioavailability and toxicity. Herein, Raloxifene-loaded polymeric nanoparticles (RLX-PNPs) were developed and investigated for the treatment of OP with possible solutions to the above mentioned problems. RLX-PNPs were prepared by modified ionic gelation method followed by determining their particle properties. FTIR, DSC and PXRD analysis of the RLX-PNPs were performed to check chemical interaction, thermal behavior and crystallinity, respectively. In-vitro release profile of RLX-PNPs was checked in lab setting, whereas its pharmacokinetics was investigated in Sprague-Dawley rats, in-vivo. Finally, the treatment potential of RLX-PNPs was analyzed in OP induced animal model. The optimized PNPs formulation indicated 134.5 nm particle size, +24.4 mV charge and 91.73% % EE. TEM analysis showed spherical and uniform sized particles with no interactions observed in FTIR analysis. In-vitro release of RLX from RLX-PNPs showed more sustained release behavior as compared to RLX-suspension. Moreover, pharmacokinetic investigations showed a significantly enhanced bioavailability of the RLX-PNPs as well as reduced serum levels of alkaline phosphatase and calcium in OP induced rats when compared with RLX-Suspension after oral administration. Findings of this study suggested that the developed RLX-PNPs have the potential to treat OP due to sustained release and improved bioavailability of the incorporated drug.

Particle preparation of pharmaceutical compounds using supercritical antisolvent process: current status and future perspectives

The low aqueous solubility and subsequently slow dissolution rate, as well as the poor bioavailability of several active pharmaceutical ingredients (APIs), are major challenges in the pharmaceutical industry. In this review, the particle engineering approaches using supercritical carbon dioxide (SC CO₂) as an antisolvent are critically reviewed. The different SC CO₂-based antisolvent processes, such as the gas antisolvent process (GAS), supercritical antisolvent process (SAS), and a solution-enhanced dispersion system (SEDS), are described. The effect of process parameters such as temperature, pressure, solute concentration, nozzle diameter, SC CO₂ flow rate, solvent type, and solution flow rate on the average particle size, particle size distribution, and particle morphology is discussed from the fundamental perspective of the SAS process. The applications of the SAS process in different formulation approaches such as solid dispersion, polymorphs, cocrystallization, inclusion complexation, and encapsulation to enhance the dissolution rate, solubility, and bioavailability are critically reviewed. This review highlights some areas where the SAS process has not been adequately explored yet. This review will be helpful to researchers working in this area or planning to explore SAS process to particle engineering approaches to tackle the challenge of low solubility and subsequently slow dissolution rate and poor bioavailability.

RGD-decorated PLGA nanoparticles improved effectiveness and safety of cisplatin for lung cancer therapy

Upon extensive pharmaceutical and biomedical research to treat lung cancer indicates that lung cancer remains one of the deadliest diseases and the leading cause of death in men and women worldwide. Lung cancer remains untreated and has a high mortality rate due to the limited potential for effective treatment with existing therapies. This highlights the urgent need to develop an effective, precise and sustainable solutions to treat lung cancer. In this study, we developed RGD receptor-targeted PLGA nanoparticles for the controlled and targeted co-delivery of cisplatin (CDDP) and upconversion nanoparticles (UCNP) in lung cancer therapy. Pluronic F127-RGD conjugate was synthesized by carbodiimide chemistry method and the conjugation was confirmed by FTIR and ¹HNMR spectroscopy techniques. PLGA nanoparticles were developed by the double emulsification method, then the surface of the prepared nanoparticles was decorated with Pluronic F127-RGD conjugate. The prepared formulations were characterized for their particle size, polydispersity index, zeta potential, surface morphology, drug encapsulation efficiency, and in vitro drug release and haemolysis studies. Pharmacokinetic studies and safety parameters in BAL fluid were assessed in rats. Histopathology of rat lung tissue was performed. The obtained results of particle sizes of the nanoparticle formulations were found 100-200 nm, indicating the homogeneity of dispersed colloidal nanoparticles formulations. Transmission Electron Microscopy (TEM) revealed the spherical shape of the prepared nanoparticles. The drug encapsulation efficiency of PLGA nanoparticles was found to range from 60% to 80% with different nanoparticles counterparts. RGD receptor-targeted PLGA nanoparticles showed controlled drug release for up to 72 h. Further, RGD receptor-targeted PLGA nanoparticles achieved higher cytotoxicity in compared to CFT, CFT, and Ciszest-50 (marketed CDDP injection). The pharmacokinetic study revealed that RGD receptor-targeted PLGA nanoparticles were 4.6-fold more effective than Ciszest-50. Furthermore, RGD receptor-targeted PLGA nanoparticles exhibited negligible damage to lung tissue, low systemic toxicity, and high biocompatible and safety in lung tissue. The results of RGD receptor-targeted PLGA nanoparticles indicated that it is a promising anticancer system that could further exploited as a potent therapeutic approach for lung cancer.

Combinatorial Approach of Thermosensitive Hydrogels and Solid Microneedles to Improve Transdermal Delivery of Valsartan: an In Vivo Proof of Concept Study

Due to the limitations of oral administration of valsartan, in this study, we aimed to develop thermosensitive hydrogel for sustained transdermal delivery and improved bioavailability of valsartan, which was further improved using solid microneedles. The thermosensitive gel formula was made using Poloxamer 407 and Poloxamer 188 in various ratios. Valsartan thermosensitive gels were evaluated for their gelation temperature, pH values, drug content, spreadability, viscosity, rheological properties, in vitro drug release, in vitro permeation, and ex vivo permeation. Finally, in vivo study was conducted, compared to oral administration. The results presented the formulations showed required characteristic for transdermal administration with desired thermosensitive properties. Based on the permeation test with and without microneedles, it was found that the use of microneedles could affect the permeation of valsartan. Specifically, the increase of microneedles' needle length also increased valsartan permeation. The combination with the highest permeation was produced by 1.55 mm MNs with the amount of drug permeated of 2.27 ± 0.01 mg. Importantly, the transdermal delivery of valsartan using this combination approach could significantly improve the bioavailability of valsartan in in vivo study. The concentration of poloxamer was able to affect the properties of the hydrogels, and the use of solid microneedles improved the transdermal delivery of valsartan. In vivo studies showed the improvement of the bioavailability of valsartan compared to oral administration, showing the effectiveness of this combination approach.

Nanoparticle and Nanostructure Synthesis and Controlled Growth Methods

Nanomaterials are materials with one or more nanoscale dimensions (internal or external) (i.e., 1 to 100 nm). The nanomaterial shape, size, porosity, surface chemistry, and composition are controlled at the nanoscale, and this offers interesting properties compared with bulk materials. This review describes how nanomaterials are classified, their fabrication, functionalization techniques, and growth-controlled mechanisms. First, the history of nanomaterials is summarized and then the different classification methods, based on their dimensionality (0-3D), composition (carbon, inorganic, organic, and hybrids), origin (natural, incidental, engineered, bioinspired), crystal phase (single phase, multiphase), and dispersion state (dispersed or aggregated), are presented. Then, the synthesis methods are discussed and classified in function of the starting material (bottom-up and top-down), reaction phase (gas, plasma, liquid, and solid), and nature of the dispersing forces (mechanical, physical, chemical, physicochemical, and biological). Finally, the challenges in synthesizing nanomaterials for research and commercial use are highlighted.

In vitro dissolution considerations associated with nano drug delivery systems

Nano drug delivery systems (NDDS) offer promising solution for the translation of future nanomedicines. As bioavailability and therapeutic outcomes can be improved by altering the drug release from these NDDS, it becomes essential to thoroughly understand their drug release kinetics. Moreover, U.S. Food and Drug Administration requires critical evaluation of potential safety, efficacy, and public health impacts of nanomaterials. Spiraling up market share of NDDS has also stimulated the pharmaceutical industry to develop their cost-effective generic versions after the expiry of patent and associated exclusivity. However, unlike the conventional dosage forms, the in vivo disposition of NDDS is highly intricate and different from their in vitro behavior. Significant challenges exist in the establishment of in vitro-in vivo correlation (IVIVC) due to incomplete understanding of nanoparticles' in vivo biofate and its impact on in vitro experimental protocols. A rational design of dissolution may serve as quality and quantity control tool and help develop a meaningful IVIVC for favorable economic implications. Clinically relevant drug product specifications (critical quality attributes) can be identified by establishing a link between in vitro performance and in vivo exposure. In vitro dissolution may also play a pivotal role to understand the dissolution-mediated clearance and safety of NDDS. Prevalent in vitro dissolution methods for NDDS and their limitations are discussed in this review, among which USP 4 is gaining more interest recently. Researchers are working diligently to develop biorelevant in vitro release assays to ensure optimal therapeutic performance of generic versions of these NDDS. This article focuses on these studies and presents important considerations for the future development of clinically relevant in vitro release methods. This article is categorized under: Toxicology and Regulatory Issues in Nanomedicine > Regulatory and Policy Issues in Nanomedicine.

Ternary solid dispersions: classification and formulation considerations

The number of active pharmaceutical compounds from the biopharmaceutical classification system (BCS) belonging to Class II and IV have significantly increased in recent years. These compounds have high therapeutic potential but are difficult to formulate as oral dosage forms due to their poor aqueous solubility. The solubility and bioavailability of these poorly water-soluble compounds can be increased by various formulation approaches, such as amorphous solid dispersions (ASD), salt formation, complexations, etc. Out of these techniques, the ASD approach, where compounds are converted into amorphous form and embedded in the hydrophilic matrix, have been successfully used in many marketed preparations. The recent advancement of this ASD approach is the design of ternary solid dispersions (TSD), where an additional component is added to further improve their performance in terms of solubility, stability, and processability. This review discusses the classification, mechanism of performance improvement, preparation techniques, and characterizations for TSD.

Pharmaceutical amorphous solid dispersion: A review of manufacturing strategies

Amorphous solid dispersions (ASDs) are popular for enhancing the solubility and bioavailability of poorly water-soluble drugs. Various approaches have been employed to produce ASDs and novel techniques are emerging. This review provides an updated overview of manufacturing techniques for preparing ASDs. As physical stability is a critical quality attribute for ASD, the impact of formulation, equipment, and process variables, together with the downstream processing on physical stability of ASDs have been discussed. Selection strategies are proposed to identify suitable manufacturing methods, which may aid in the development of ASDs with satisfactory physical stability.

Nanostructured Valsartan Microparticles with Enhanced Bioavailability Produced by High-Throughput Electrohydrodynamic Room-Temperature Atomization

The high-throughput drying and encapsulation technique called electrospraying assisted by pressurized gas (EAPG) was used for the first time to produce nanostructured valsartan within microparticles of excipients. Valsartan, a poorly absorbed and lipid-soluble drug, was selected since it is considered a good model for BCS class II drugs. Two different polymeric matrices were selected as excipients, i.e., hydroxypropyl methylcellulose (HPMC) and lactose monohydrate, while Span 20 was used as a surfactant. The produced 80% valsartan loading formulations were characterized in terms of morphology, crystallinity, in vitro release, in vitro Caco-2 cells’ permeability, and in vivo pharmacokinetic study. Spherical microparticles of ca. 4 μm were obtained within which valsartan nanoparticles were seen to range from 150 to 650 nm. Wide-angle X-ray scattering and differential scanning calorimetry confirmed that valsartan had a lower and/or more ill-defined crystallinity than the commercial source, and photon correlation spectroscopy and transmission electron microscopy proved that it was dispersed and distributed in the form of nanoparticles of controlled size. In vitro dissolution tests showed that the HPMC formulation with the lowest API particle size, i.e., 150 nm, dissolved 2.5-fold faster than the commercial valsartan in the first 10 min. This formulation also showed a 4-fold faster in vitro permeability than the commercial valsartan and a 3-fold higher systemic exposure than the commercial sample. The results proved the potential of the EAPG processing technique for the production of safe-to-handle microparticles containing high quantities of a highly dispersed and distributed nanonized BCS class II model drug with enhanced bioavailability.

Drug-Rich Phases Induced by Amorphous Solid Dispersion: Arbitrary or Intentional Goal in Oral Drug Delivery?

Among many methods to mitigate the solubility limitations of drug compounds, amorphous solid dispersion (ASD) is considered to be one of the most promising strategies to enhance the dissolution and bioavailability of poorly water-soluble drugs. The enhancement of ASD in the oral absorption of drugs has been mainly attributed to the high apparent drug solubility during the dissolution. In the last decade, with the implementations of new knowledge and advanced analytical techniques, a drug-rich transient metastable phase was frequently highlighted within the supersaturation stage of the ASD dissolution. The extended drug absorption and bioavailability enhancement may be attributed to the metastability of such drug-rich phases. In this paper, we have reviewed (i) the possible theory behind the formation and stabilization of such metastable drug-rich phases, with a focus on non-classical nucleation; (ii) the additional benefits of the ASD-induced drug-rich phases for bioavailability enhancements. It is envisaged that a greater understanding of the non-classical nucleation theory and its application on the ASD design might accelerate the drug product development process in the future.

Development of a Solid Supersaturable Micelle of Revaprazan for Improved Dissolution and Oral Bioavailability Using Box-Behnken Design

PURPOSE

To enhance the oral bioavailability of revaprazan (RVP), a novel solid, supersaturable micelle (SSuM) was developed.

METHODS

Surfactants and solid carriers were screened based on a solubility and a flowability test, respectively. Supersaturating agents, including Poloxamer 407 (P407), were screened. The SSuM was optimized using a Box-Behnken design with three independent variables, including Gelucire 44/14:Brij L4 (G44/BL4; X1) and the amounts of Florite PS-10 (FLO; X2) and Vivapur 105 (VP105; X3), and three response variables, ie, dissolution efficiency at 30 min (Y1), dissolution enhancing capacity (Y2), and Carr's index (Y3). The solid state property was evaluated, and a dissolution test was conducted. RVP, Revanex®, solid micelle (P407-free from the composition of SSuM), and SSuM were orally administrated to rats (RVP 20 mg equivalent/kg) for in vivo pharmacokinetic study.

RESULTS

G44 and BL4 showed great solubility, with a critical micelle concentration range of 119.2-333.0 μg/mL. P407 had an excellent supersaturating effect. FLO and VP105 were selected as solid carriers, with a critical solidifying ratio (g/mL) of 0.30 and 0.91, respectively. With optimized values of X1 (-0.41), X2 (0.31), and X3 (-0.78), RVP (200 mg)-containing SSuM consisting of G44 (253.8 mg), BL4 (106.2 mg), FLO (99.3 mg), VP105 (199.8 mg), and P407 (40 mg) was developed, resulting in Y1 (40.3%), Y2 (0.008), and Y3 (12.3%). RVP existed in an amorphous state in the optimized SSuM, and the SSuM formed a nanosized dispersion in the aqueous phase, with approximately 71.7% dissolution at 2 h. The optimized SSuM improved the relative bioavailability of RVP in rats by approximately 478%, 276%, and 161% compared to raw RVP, Revanex®, and solid micelle, respectively.

CONCLUSION

The optimized SSuM has great potential for the development of solidified formulations of poorly water-soluble drugs with improved oral absorption.

Optimization of solid self-dispersing micelle for enhancing dissolution and oral bioavailability of valsartan using Box-Behnken design

A novel solid self-dispersing micelle (S-SDM) was developed to enhance the oral bioavailability of valsartan (VST) and to reduce the total mass of solidified supersaturable self-microemulsifying drug delivery system (S-SuSMEDDS), composed of Capmul MCM, Tween 80 (T80), Gelucire 44/14 (G44), Poloxamer 407, Florite PS-10 (FLO), and low-substituted hydroxypropyl cellulose B1 (HPC). Excluding oil component from S-SuSMEDDS, S-SDM was optimized using a Box-Behnken design with three independent variables: X₁ (T80/G44, 0.63), X₂ (FLO/HPC, 0.41), and X₃ (solid carrier, 177.6 mg); and three response factors: Y₁ (droplet size, 191.9 nm), Y₂ (dissolution efficiency at 15 min, 55.0%), and Y₃ (angle of repose, 32.4°). The desirability function was 0.636, showing an excellent agreement between the predicted and experimental values. With approximately 75% weight of S-SuSMEDDS, no distinct crystallinity of VST was observed in S-SDM, resulting in critical micelle concentration value of 32 μg/mL. Optimized S-SDM showed an approximate 4-fold improved dissolution (pH 1.2, 500 mL) compared with raw VST. Following oral administration in rats, optimized S-SDM improved relative bioavailability by approximately 235%, 216%, and 127% versus raw VST, Diovan® (commercial reference), and S-SuSMEDDS, respectively. Thus, optimized S-SDM could be a selectable candidate for developing water-insoluble drugs in reduced quantity.

Enhanced oral bioavailability of valsartan in rats using a supersaturable self-microemulsifying drug delivery system with P-glycoprotein inhibitors

Valsartan (VST) is a poorly water-soluble drug and a P-glycoprotein (P-gp) substrate. To enhance the dissolution and oral absorption of VST, a novel supersaturable self-microemulsifying drug delivery system (Su-SMEDDS) was formulated. Based on the previously reported Su-SMEDDS composed of Capmul^® MCM (oil), Tween^® 20 (T20; surfactant), Transcutol^® P (cosurfactant), and Poloxamer 407 (supersaturating agent), P-gp inhibitory surfactants including Tween^® 80 (T80) and Cremophor^® EL (CR) were newly introduced to replace T20. All Su-SMEDDS formulations had a droplet size of <200 nm and showed rapid (>90% within 5 min) and pH-independent dissolution characteristics. The effective permeability coefficient (P_eff) in rat jejunum was obtained using an in situ single-pass intestinal perfusion study: P_eff values of Su-SMEDDS-T20, Su-SMEDDS-T80, and Su-SMEDDS-CR were 2.3, 4.1, and 3.4 times greater, respectively, than that of the VST solution. After oral administration of various formulations to rats (equivalent dose of VST 10 mg/kg), plasma drug levels were measured by liquid chromatography-tandem mass spectrometry. The relative bioavailabilities of Su-SMEDDS-T20, Su-SMEDDS-T80, and Su-SMEDDS-CR were 262%, 470%, and 458%, respectively, compared with the VST suspension. Thus, we propose that the Su-SMEDDS-T80 formulation is a good candidate for improving the oral absorption of poorly water-soluble and P-gp substrate drugs such as VST.

Development of sorafenib loaded nanoparticles to improve oral bioavailability using a quality by design approach

Sorafenib, a potent anticancer drug, has low absorption in the gastrointestinal tract due to its poor aqueous solubility. The main purpose of this investigation was to design sorafenib nanoparticle using a newly developed technique, nanoparticulation using fat and supercritical fluid (NUFS™) to improve the absorption of sorafenib. The quality by design (QbD) tool was adopted to define the optimal formulation variables: hydroxypropyl methyl cellulose (HPMC), polyvinyl pyrrolidone K30 (PVP), and poloxamer. The studied response variables were particle size of nanoparticle, dissolution (5, 60, and 180 min), drug concentration time profile of nanoparticle formulations, and maximum drug concentration. The result of particle size revealed that an increase in concentration of poloxamer and HPMC decreased the particle size of nanoparticles (p < 0.05). Likewise, the concentration of drug release at different time point (5, 60, and 180 min) showed HPMC and poloxamer had positive effects on drug dissolution while PVP had negative effects on it. The design space was built in accordance with the particle size of nanoparticle (target < 500 nm) and dissolution of sorafenib (target > 7 µm/mL), following failure probability analysis using Monte Carlo simulations. In vivo pharmacokinetics studies in beagle dogs demonstrated that optimized formulation of sorafenib (F3 and F4 tablets) exhibited higher blood drug profiles indicating better absorption compared to the reference tablet (Nexavar^®). In conclusion, this study showed the importance of systematic formulation design for understanding the effect of formulation variables on the characteristics of nanoparticles of the poorly soluble drug.

The Self-Assembly Phenomenon of Poloxamers and Its Effect on the Dissolution of a Poorly Soluble Drug from Solid Dispersions Obtained by Solvent Methods

The self-assembly phenomenon of amphiphiles has attracted particular attention in recent years due to its wide range of applications. The formation of nanoassemblies able to solubilize sparingly water-soluble drugs was found to be a strategy to solve the problem of poor solubility of active pharmaceutical ingredients. Binary and ternary solid dispersions containing Biopharmaceutics Classification System (BCS) class II drug bicalutamide and either Poloxamer®188 or Poloxamer®407 as the surface active agents were obtained by either spray drying or solvent evaporation under reduced pressure. Both processes led to morphological changes and a reduction of particle size, as confirmed by scanning electron microscopy and laser diffraction measurements. The increase in powder wettability was confirmed by means of contact angle measurements. The effect of an alteration of the crystal structure was followed by powder X-ray diffractometry while thermal properties were determined using differential scanning calorimetry. Interestingly, bicalutamide exhibited a polymorph transition after spray drying with the poloxamer and polyvinylpyrrolidone (PVP), while the poloxamer underwent partial amorphization. Moreover, due to the surface activity of the carrier, the solid dispersions formed nanoaggregates in water, as confirmed using dynamic light scattering measurements. The aggregates measuring 200⁻300 nm in diameter were able to solubilize bicalutamide inside the hydrophobic inner parts. The self-assembly of binary systems was found to improve the amount of dissolved bicalutamide by 4- to 8-fold in comparison to untreated drug. The improvement in drug dissolution was correlated with the solubilization of poorly soluble molecules by macromolecules, as assessed using emission spectroscopy.

Oral vitamin-A-coupled valsartan nanomedicine: High hepatic stellate cell receptors accessibility and prolonged enterohepatic residence

So far, liver fibrosis still has no clinically-approved treatment. The loss of stored vitamin-A (V_A) in hepatic stellate cells (HSCs), the main regulators to hepatic fibrosis, can be applied as a mechanism for their targeting. Valsartan is a good candidate for this approach; it is a marketed oral-therapy with inverse- and partial-agonistic activity to the over-expressed angiotensin-II type1 receptor (AT1R) and depleted nuclear peroxisome proliferator-activated receptor-gamma (PPAR-γ), respectively, in activated HSCs. However, efficacy on AT1R and PPAR-γ necessitates high drug permeability which is lacking in valsartan. In the current study, liposomes were used as nanocarriers for valsartan to improve its permeability and hence efficacy. They were coupled to V_A and characterized for HSCs-targeting. Tracing of orally-administered fluorescently-labeled V_A-coupled liposomes in normal rats and their fluorescence intensity quantification in different organs convincingly demonstrated their intestinal entrapment. On the other hands, their administration to rats with induced fibrosis revealed preferential hepatic, and less intestinal, accumulation which lasted up to six days. This indicated their uptake by intestinal stellate cells that acted as a depot for their release over time. Confocal microscopical examination of immunofluorescently-stained HSCs in liver sections, with considerable formula accumulation, confirmed HSCs-targeting and nuclear uptake. Consequently, V_A-coupled valsartan-loaded liposomes (VLC)-therapy resulted in profound re-expression of hepatic Mas-receptor and PPAR-γ, potent reduction of fibrogenic mediators' level and nearly normal liver function tests. Therefore, VLC epitomizes a promising antifibrotic therapy with exceptional extended action and additional PPAR-γ agonistic activity.

Enhanced oral bioavailability of valsartan using a polymer-based supersaturable self-microemulsifying drug delivery system

A novel, supersaturable self-microemulsifying drug delivery system (S-SMEDDS) was successfully formulated to enhance the dissolution and oral absorption of valsartan (VST), a poorly water-soluble drug, while reducing the total quantity for administration. Poloxamer 407 is a selectable, supersaturating agent for VST-containing SMEDDS composed of 10% Capmul® MCM, 45% Tween® 20, and 45% Transcutol® P. The amounts of SMEDDS and Poloxamer 407 were chosen as formulation variables for a 3-level factorial design. Further optimization was established by weighting different levels of importance on response variables for dissolution and total quantity, resulting in an optimal S-SMEDDS in large quantity (S-SMEDDS_LQ; 352 mg in total) and S-SMEDDS in reduced quantity (S-SMEDDS_RQ; 144.6 mg in total). Good agreement was observed between predicted and experimental values for response variables. Consequently, compared with VST powder or suspension and SMEDDS, both S-SMEDDS_LQ and S-SMEDDS_RQ showed excellent in vitro dissolution and in vivo oral bioavailability in rats. The magnitude of dissolution and absorption-enhancing capacities using quantity-based comparisons was in the order S-SMEDDS_RQ > S-SMEDDS_LQ > SMEDDS > VST powder or suspension. Thus, we concluded that, in terms of developing an effective SMEDDS preparation with minimal total quantity, S-SMEDDS_RQ is a promising candidate.

Amorphous solid dispersions: Rational selection of a manufacturing process

Amorphous products and particularly amorphous solid dispersions are currently one of the most exciting areas in the pharmaceutical field. This approach presents huge potential and advantageous features concerning the overall improvement of drug bioavailability. Currently, different manufacturing processes are being developed to produce amorphous solid dispersions with suitable robustness and reproducibility, ranging from solvent evaporation to melting processes. In the present paper, laboratorial and industrial scale processes were reviewed, and guidelines for a rationale selection of manufacturing processes were proposed. This would ensure an adequate development (laboratorial scale) and production according to the good manufacturing practices (GMP) (industrial scale) of amorphous solid dispersions, with further implications on the process validations and drug development pipeline.

Development of megestrol acetate solid dispersion nanoparticles for enhanced oral delivery by using a supercritical antisolvent process

In the present study, solid dispersion nanoparticles with a hydrophilic polymer and surfactant were developed using the supercritical antisolvent (SAS) process to improve the dissolution and oral absorption of megestrol acetate. The physicochemical properties of the megestrol acetate solid dispersion nanoparticles were characterized using scanning electron microscopy, differential scanning calorimetry, powder X-ray diffraction, and a particle-size analyzer. The dissolution and oral bioavailability of the nanoparticles were also evaluated in rats. The mean particle size of all solid dispersion nanoparticles that were prepared was <500 nm. Powder X-ray diffraction and differential scanning calorimetry measurements showed that megestrol acetate was present in an amorphous or molecular dispersion state within the solid dispersion nanoparticles. Hydroxypropylmethyl cellulose (HPMC) solid dispersion nanoparticles significantly increased the maximum dissolution when compared with polyvinylpyrrolidone K30 solid dispersion nanoparticles. The extent and rate of dissolution of megestrol acetate increased after the addition of a surfactant into the HPMC solid dispersion nanoparticles. The most effective surfactant was Ryoto sugar ester L1695, followed by D-α-tocopheryl polyethylene glycol 1000 succinate. In this study, the solid dispersion nanoparticles with a drug:HPMC:Ryoto sugar ester L1695 ratio of 1:2:1 showed >95% rapid dissolution within 30 minutes, in addition to good oral bioavailability, with approximately 4.0- and 5.5-fold higher area under the curve (0–24 hours) and maximum concentration, respectively, than raw megestrol acetate powder. These results suggest that the preparation of megestrol acetate solid dispersion nanoparticles using the supercritical antisolvent process is a promising approach to improve the dissolution and absorption properties of megestrol acetate.

Improving dissolution and oral bioavailability of pranlukast hemihydrate by particle surface modification with surfactants and homogenization

The present study was carried out to develop an oral formulation of pranlukast hemihydrate with improved dissolution and oral bioavailability using a surface-modified microparticle. Based on solubility measurements, surface-modified pranlukast hemihydrate microparticles were manufactured using the spray-drying method with hydroxypropylmethyl cellulose, sucrose laurate, and water and without the use of an organic solvent. The hydrophilicity of the surface-modified pranlukast hemihydrate microparticle increased, leading to enhanced dissolution and oral bioavailability of pranlukast hemihydrate without a change in crystallinity. The surface-modified microparticles with an hydroxypropylmethyl cellulose/sucrose laurate ratio of 1:2 showed rapid dissolution of up to 85% within 30 minutes in dissolution medium (pH 6.8) and oral bioavailability higher than that of the commercial product, with approximately 2.5-fold and 3.9-fold increases in area under the curve (AUC_{0→12 h}) and peak plasma concentration, respectively. Therefore, the surface-modified microparticle is an effective oral drug delivery system for the poorly water-soluble therapeutic pranlukast hemihydrate.

Soluplus®/TPGS-based solid dispersions prepared by hot-melt extrusion equipped with twin-screw systems for enhancing oral bioavailability of valsartan

BACKGROUND

Soluplus(®) (SP) and D-alpha-tocopherol polyethylene glycol 1000 succinate (TPGS)-based solid dispersion (SD) formulations were developed by hot-melt extrusion (HME) to improve oral bioavailability of valsartan (VST).

METHODS

HME process with twin-screw configuration for generating a high shear stress was used to prepare VST SD formulations. The thermodynamic state of the drug and its dispersion in the polymers were evaluated by solid-state studies, including Fourier-transform infrared, X-ray diffraction, and differential scanning calorimetry. Drug release from the SD formulations was assessed at pH values of 1.2, 4.0, and 6.8. Pharmacokinetic study was performed in rats to estimate the oral absorption of VST.

RESULTS

HME with a high shear rate produced by the twin-screw system was successfully applied to prepare VST-loaded SD formulations. Drug amorphization and its molecular dispersion in the polymer matrix were verified by several solid-state studies. Drug release from SD formulations was improved, compared to the pure drug, particularly at pH 6.8. Oral absorption of drug in rats was also enhanced in SP and TPGS-based SD groups compared to that in the pure drug group.

CONCLUSION

SP and TPGS-based SDs, prepared by the HME process, could be used to improve aqueous solubility, dissolution, and oral absorption of poorly water-soluble drugs.

Preparation and in vivo evaluation of a dutasteride-loaded solid-supersaturatable self-microemulsifying drug delivery system

The purpose of this study was to prepare a dutasteride-loaded solid-supersaturatable self-microemulsifying drug delivery system (SMEDDS) using hydrophilic additives with high oral bioavailability, and to determine if there was a correlation between the in vitro dissolution data and the in vivo pharmacokinetic parameters of this delivery system in rats. A dutasteride-loaded solid-supersaturatable SMEDDS was generated by adsorption of liquid SMEDDS onto Aerosil 200 colloidal silica using a spray drying process. The dissolution and oral absorption of dutasteride from solid SMEDDS significantly increased after the addition of hydroxypropylmethyl cellulose (HPMC) or Soluplus. Solid SMEDDS/Aerosil 200/Soluplus microparticles had higher oral bioavailability with 6.8- and 5.0-fold higher peak plasma concentration (C_max) and area under the concentration-time curve (AUC) values, respectively, than that of the equivalent physical mixture. A linear correlation between in vitro dissolution efficiency and in vivo pharmacokinetic parameters was demonstrated for both AUC and C_max values. Therefore, the preparation of a solid-supersaturatable SMEDDS with HPMC or Soluplus could be a promising formulation strategy to develop novel solid dosage forms of dutasteride.

The ameliorated longevity and pharmacokinetics of valsartan released from a gel system of ultradeformable vesicles

OBJECTIVE

The present study traces the development and characterization of the gel formulation of valsartan-loaded ultradeformable vesicles for management of hypertension.

MATERIALS AND METHODS

The prepared gel formulation of ultradeformable vesicles was evaluated for in vitro skin permeation, release kinetics, skin irritation, pharmacokinetics, and stability.

RESULTS AND DISCUSSION

The in vitro skin permeation study showed that the gel formulation of ultradeformable vesicles presented a flux value of 368.74 μg/cm(2)/h, in comparison to that of the traditional liposomal gel formulation, with an enhancement ratio of 26.91, through rat skin. The data for release kinetics showed that the release profile followed zero-order kinetics, and that the drug release mechanism was non-Fickian. The results of the skin irritation study demonstrated that the prepared formulation was safe, less irritant, and well-tolerated for transdermal delivery. The results of the pharmacokinetic study demonstrated that the AUC value of valsartan after transdermal administration was apparently increased. The formulation stored under a refrigerated condition showed greater stability, and results were found to be within the specification under storage conditions.

CONCLUSION

It is evident from this study that the gel formulation of ultradeformable vesicles of valsartan is a promising delivery system for lipophilic drugs, and has reasonably good stability characteristics.

Formulation, characterization, and in vivo evaluation of celecoxib-PVP solid dispersion nanoparticles using supercritical antisolvent process

The aim of this study was to develop celecoxib-polyvinylpyrrolidone (PVP) solid dispersion nanoparticles with and without surfactant using the supercritical antisolvent (SAS) process. The effect of different surfactants such as gelucire 44/14, poloxamer 188, poloxamer 407, Ryoto sugar ester L1695, and d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) on nanoparticle formation and dissolution as well as oral absorption of celecoxib-PVP K30 solid dispersion nanoparticles was investigated. Spherical celecoxib solid dispersion nanoparticles less than 300 nm in size were successfully developed using the SAS process. Analysis by differential scanning calorimetry and powder X-ray diffraction showed that celecoxib existed in the amorphous form within the solid dispersion nanoparticles fabricated using the SAS process. The celecoxib-PVP-TPGS solid dispersion nanoparticles significantly enhanced in vitro dissolution and oral absorption of celecoxib relative to that of the unprocessed form. The area under the concentration-time curve (AUC0→24 h) and peak plasma concentration (Cmax) increased 4.6 and 5.7 times, respectively, with the celecoxib-PVP-TPGS formulation. In addition, in vitro dissolution efficiency was well correlated with in vivo pharmacokinetic parameters. The present study demonstrated that formulation of celecoxib-PVP-TPGS solid dispersion nanoparticles using the SAS process is a highly effective strategy for enhancing the bioavailability of poorly water-soluble celecoxib.