Freeze dried solid dispersion of exemestane: A way to negate an aqueous solubility and oral bioavailability problems

Supersaturable diacyl phospholipid dispersion for improving oral bioavailability of brick dust molecule: A case study of Aprepitant

This study aims to investigate the potential use of polymer inclusion in the phospholipid-based solid dispersion approach for augmenting the biopharmaceutical performance of Aprepitant (APT). Initially, different polymers were screened using the microarray plate method to assess their ability to inhibit drug precipitation in the supersaturated solution and HPMCAS outperformed the others. Later, the binary (BD) and ternary (TD) phospholipid dispersions were prepared using the co-solvent evaporation method. Solid-state characterization was performed using SEM and PXRD to examine the physical properties, while molecular interactions were probed through FTIR and NMR analysis. In vitro dissolution studies were performed in both fasted and fed state biorelevant media. The results demonstrated a substantial increase in drug release from BD and TD, approximately 4.8 and 9.9 times higher compared to crystalline APT in FaSSIF. Notably, TD also showed a lowered dissolution difference between fed and fasted states in comparison to crystalline APT, indicating a reduction in the positive food effect of APT. Moreover, we assessed the impact of polymer inclusion on permeation under in vitro biomimetic conditions. In comparison with the crystalline APT suspension, both BD and TD demonstrated approximately 3.3 times and 14 times higher steady-state flux (Jss values), respectively. This can be ascribed to the supersaturation and presence of drug-rich submicron particles (nanodroplets) along with the multiple aggregates of drug with phospholipids and polymer in the donor compartment, consequently resulting in a more substantial driving force for passive diffusion. Lastly, in vivo pharmacokinetic evaluation demonstrated the enhanced absorption of both TD and BD over the free drug suspension in the fasted state. This enhancement was evident through a 2.1-fold and 1.3-fold increase in Cmax and a 2.3-fold and 1.4-fold increase in AUC0-t, respectively. Overall, these findings emphasize the potential of polymer-based phospholipid dispersion in enhancing the overall biopharmaceutical performance of APT.

Incorporation of exemestane into ternary nanosponge system for enhanced anti-tumor potential in breast cancer

The present investigation reports the potential of exemestane loaded cyclodextrin based nanosponges for the treatment of breast cancer. Fourier transform infrared, and nuclear magnetic resonance (NMR) spectroscopic analysis confirmed the encapsulation of ring B, C, and D of exemestane in the nanosponge cavity. In vitro studies demonstrated a 6.58-folds increase in the aqueous solubility and a 1.76-folds increase in the dissolution of exemestane in the optimized nanosponge formulation EF2. It also exhibited enhanced cytotoxicity in MCF-7 cell line. Pharmacokinetic studies revealed a 1.37-fold increase in Cmax and a 2.10-fold increase in oral bioavailability of EF2, as compared to its marketed product Aromasin®. Concomitantly, this nano-formulation reduced the tumor burden to 45.71% in a DMBA-induced breast cancer rat model. This EF2-treatment also improved the hematological parameters of the animals. Histopathology of breast tissue also presented reduction in characteristic cytoarchitectural features of breast tumor. In vivo toxicity studies demonstrated reduced hepatotoxicity of the nanosponge formulation when compared with Aromasin®. These results were further supported by histological studies of excised liver tissues, where the size of hepatocytes in EF2-treated animals was like the normal hepatocyte size. In conclusion, the encapsulation of exemestane in β-cyclodextrin nanosponge along-with HPMC E5 improved its aqueous solubility, bioavailability, and ultimately therapeutic efficacy for the treatment of breast cancer.

Effect of variables on exemestane-loaded albumin nanoparticles: statistical optimization and anti-cancer activity in MCF-7 cell lines

This research aimed to evaluate the effect of variables on exemestane-loaded bovine serum albumin nanoparticles (EXE-BSA NPs) to improve anti-breast cancer activity. EXE-BSA NPs were optimized using 32 factorial design, wherein the concentration of BSA (X1) and sonication time (X2) were independent variables and particle size (Y1) and %w/w entrapment efficiency (Y2) were dependent variables. The statistical optimization revealed a significant effect of BSA concentration on both variables, whereas sonication time affected only particle size. The optimized EXE-BSA NPs were spherical with 124.1 ± 2.62 nm particle size, 83.95 ± 1.06% w/w drug entrapment, and exhibited a biphasic release of 100% (w/w) drug over 72 h. The optimized formulation induced cytotoxicity in MCF-7 cell lines with an IC50 value of 21.46 µg/mL by MTT assay, almost half the free drug (54.87 µg/mL). Thus, statistically optimized EXE-BSA NPs were effective in MCF-7 cell lines and can be explored to treat estrogen receptor-positive breast cancer.

Promising strategies for improving oral bioavailability of poor water-soluble drugs

INTRODUCTION

Oral administration of poorly water-soluble drugs (PWSDs) is generally related to low bioavailability, leading to high drug doses, multiple side effects, and low patient compliance. Thus, different strategies have been developed to increase drug solubility and dissolution in the gastrointestinal tract, opening new venues for these drugs.

AREAS COVERED

This review outlines the current challenges in PWSD formulation development and the strategies to overcome the oral barriers and increase their solubility and bioavailability. Conventional strategies include altering crystalline and molecular structures and modifying oral solid dosage forms. In contrast, novel strategies comprise micro- and nanostructured systems. Recent representative studies involving how these strategies have improved the oral bioavailability of PWSDs were also reviewed and reported.

EXPERT OPINION

New approaches to enhance PWSD bioavailability have sought to improve water solubility and dissolution rates, drug protection by overcoming biological barriers, and increased absorption. Still, only a handful of studies have focused on quantifying the increase in bioavailability. Improving the oral bioavailability of PWSDs remains an exciting unexplored field of research and has become an important issue for successfully developing pharmaceutical products.

Fabrication of betamethasone micro- and nanoparticles using supercritical antisolvent technology: In vitro drug release study and Caco-2 cell cytotoxicity evaluation

Poor solubility limits the pharmacological activities of betamethasone (BM), including its anti-inflammatory and anti-allergic effects. To improve the aqueous solubility and dissolution rate of BM, supercritical antisolvent (SAS) technology was used to prepare BM microparticles and BM-polyvinylpyrrolidone (PVP) solid dispersion nanoparticles. The effects of temperature, pressure, solution feeding rate, and drug concentration on particle formation were investigated using both single-factor and orthogonal experimental methods, and the optimal preparation process was screened. The physicochemical properties of the BM particles were characterized by scanning electron microscopy, differential scanning calorimetry, Fourier transform infrared spectroscopy, and X-ray diffraction. After the SAS process, the particle size was reduced significantly and the crystalline shape was altered, which considerably increased the solubility and dissolution rate of BM. Furthermore, the toxicity of BM to live cells was reduced because of the BM-PVP solid dispersions.

Reduced the Food Effect and Enhanced the Oral Bioavailability of Ivacaftor by Self-Nanoemulsifying Drug Delivery System (SNEDDS) Using a New Oil Phase

Purpose

The purpose of this work was to develop an ivacaftor self-nanoemulsion drug delivery system (IVA-SNEDDS) using the newly developed double headed miscellaneous lipid (DHML) as oil phase to reduce the food effect and inter-individual absorption variability of IVA.

Methods

The lipids with the greatest solubility to IVA were selected as the oil phase of IVA-SNEDDS by saturation solubility method. Then, among different surfactants and co-surfactants, those with good emulsifying ability for the selected oil phase were selected, and the proportion of surfactant and co-surfactant was further selected by pseudo-ternary phase diagram. The prepared IVA-SNEDDS were screened and evaluated in vitro and in beagle dogs.

Results

The optimized IVA-SNEDDS formulation consisting of DHML, Tween 80, and Transcutol HP with the weight ratio of 2:2:1 was physically stable and it was easy to disperse in water, pH 1.2 hydrochloric acid and pH 6.8 phosphate buffer solution, and generated a fine homogeneous nanoemulsion, with mean globule size less than 75 nm regardless of dilution ratio. In vitro drug release studies showed that the drug in IVA-SNEDDS could be completely released in a short time, while the drug release in IVA-suspension was less than 1% at 60 min. In vivo, using IVA-suspension (Fed) as a reference, the relative oral bioavailability of IVA-suspension (Fasted), IVA-SNEDDS (Fasted), and IVA-SNEDDS (Fed) were 23.35%, 153.63%, and 149.89%, respectively. This showed that IVA-SNEDDS could eliminate the positive food effect, improve the oral bioavailability, and reduce the IVA absorption difference between individuals.

Conclusion

As the oil phase of SNEDDS, DHML can significantly improve the drug solubility and drug loading of IVA-SNEDDS. Moreover, DHML was easily emulsified and can effectively form a nanoemulsion in vivo and in vitro. The prepared IVA-SNEDDS can reduce the inter-individual absorption variability of IVA, eliminate its food effect and improve its oral bioavailability.

Application of supercritical fluid technology for solid dispersion to enhance solubility and bioavailability of poorly water-soluble drugs

Many new chemical entities (NCEs) have been discovered with the development of the pharmaceutical industry. However, the main disadvantage of these drugs is their low aqueous solubility, which results in poor bioavailability, posing a challenge for pharmaceutical scientists in the field of drug development. Solid dispersion (SD) technology is one of the most successful techniques used to resolve these problems. SD has been widely used to improve the solubility and bioavailability of poorly water-soluble drugs using several methods such as melting, supercritical fluid (SCF), solvent evaporation, spray drying, hot-melt extrusion, and freeze-drying. Among them, SCF with carbon dioxide (CO₂) has recently attracted great attention owing to its enhanced dissolution and bioavailability with non-toxic, economical, non-polluting, and high-efficiency properties. Compared with the conventional methods using organic solvents in the preparation of the formulation (solvent evaporation method), SCF used CO₂ to replace the organic solvent with high pressure to avoid the limitation of solvent residues. The solubility of a substance in CO₂ plays an important role in the success of the formulation. In the present review, the various processes involved in SCF technology, application of SCF to prepare SD, and future perspectives of SCF are described.

Combination of Phospholipid Complex and Matrix Dispersion

Phospholipid complexation, despite being a successful, versatile, and burgeoning strategy, stickiness of phospholipids leads to suboptimal dissolution rate of drugs. This work was undertaken to fabricate simvastatin-phospholipid complex (SIM-PLC)-loaded matrix dispersion (SIM-PLC-MD) using Soluplus® as carrier material, to augment dispersibility and dissolution of SIM-PLC without altering complexation between simvastatin (SIM) and phospholipid. SIM-PLC and SIM-PLC-MD were prepared using solvent evaporation and discontinuous solvent evaporation techniques, respectively. The successful complexation was substantiated by FTIR method. Besides, PXRD and SEM studies disclosed the absence of crystallinity of SIM in both SIM-PLC and SIM-PLC-MD. The TEM analysis monitored the self-assembly of SIM-PLC and SIM-PLC-MD into colloidal structures, which could be correlated with redispersion in GIT fluids upon oral administration. The considerable increase in hydrophilicity of SIM-PLC-MD and SIM-PLC as evident from partition coefficient experiment can further be correlated with their remarkably improved solubility profiles in the following pattern: SIM-PLC-MD˃SIM-PLC˃SIM. Correspondingly, improved dispersibility of SIM-PLC-MD in comparison to SIM-PLC can be accountable for accelerated dissolution rate by 2.53-fold and 1.5-fold in pH 1.2 and 6.8 conditions, respectively. The oral pharmacokinetic evaluation in Sprague Dawley (SD) rats revealed 3.19-fold enhancement in oral bioavailability of SIM through SIM-PLC-MD when compared with plain SIM, whereas 1.83-fold increment was observed in the case of SIM-PLC. Finally, the efficacy experimentation in SD rats revealed that SIM-PLC-MD significantly reduced triglycerides and cholesterol levels in comparison to SIM and SIM-PLC. These outcomes suggest that a matrix dispersion strategy improves oral bioavailability and hypolipidemic activity of SIM.

Thermoresponsive liquid crystalline formulation of Exemestane: Design and structural characterization

Exemestane (EXE), a drug used for the treatment of breast cancer, has limited aqueous solubility of 0.08 mg/mL and log P∼ 4.22. The only available marketed formulation in form of tablets possess limitations of poor oral absorption (∼ 42 %), low solubility, extensive hepatic metabolism and numerous adverse effects due to its peripheral absorption. In order to address these issues, an alternative route of topical application is attempted through a lamellar liquid crystal based formulation. Pluronic® was used as stabilizer due to its higher surface activity and gelling properties. The solubility enhancement of EXE was achieved using liquid crystal formulation. We have investigated the effect of concentration of oil, S_mix (surfactant - cosurfactant mixture) and EXE on lattice parameter, rheology and drug release for various combinations of the formulation. The small angle x-ray scattering (SAXS) measurement demonstrated an evidence of a lamellar structure with lattice parameter ∼15 nm, which increases with corresponding increase in oil and EXE due to increase in hydrophobic interactions leading to an expansion of lamella. The inter lamellar distance decreases at higher surfactant concentration, due to the distribution of the same amount of oil and drug within larger concentration of surfactant molecules. The rheology measurement exhibited gel like properties at low shear rate indicating soft gel formation, which converts to Newtonian type flowing liquid at higher shear rate. At constant S_mix with increasing oil content, the viscosity decreases, which is attributed to the dilution of the lamellar structures with oil. The temperature sweep rheology reveals a change in the viscosity near physiological temperature, which may be attributed to the structural transition of lamellae. The formulation remains gel like at room temperature, which aids in proper application to skin and converts it to free flowing liquid above 37 °C. The invitro drug release of optimized formulation for 24 h was ∼ 38 % at 37 °C, which increased to 50 % at 42 °C. Accordingly, this formulation containing thermoresponsive lamellar liquid crystal gels of EXE represents a viable option for hyperthermia induced enhanced drug release. The characteristic and advantageous features offered by this formulation includes improved bioavailability of EXE due to enhanced solubility, permeability and absorption.

Potential of solid dispersions to enhance solubility, bioavailability, and therapeutic efficacy of poorly water-soluble drugs: newer formulation techniques, current marketed scenario and patents

In the last few decades, solid dispersion (SD) technology had been studied as an approach to produce an amorphous carrier to enhance the solubility, dissolution rate, and bioavailability of poorly water-soluble drugs. The use of suitable carrier and methodology in the preparation of SDs play a significant role in the biological behavior of the SDs. SDs have been prepared using a variety of pharmaceutically acceptable polymers utilizing various novel technologies. In the recent years, much attention has been paid toward the use of novel carriers and methodologies in exploring novel types of SDs to enhance therapeutic efficacy and bioavailability. The use of novel carriers and methodologies would be very beneficial for formulation scientists to develop some SDs-based formulations for their commercial use and clinical applications. In the present review, current literature of novel methodologies for SD preparation to enhance the dissolution rate, solubility, therapeutic efficacy, and bioavailability of poorly water-soluble drugs has been summarized and analyzed. Further, the current status of SDs, patent status, and future prospects have also been discussed.

Do Phospholipids Boost or Attenuate Drug Absorption? In Vitro and In Vivo Evaluation of Mono- and Diacyl Phospholipid-Based Solid Dispersions of Celecoxib

Phospholipids are amphiphilic lipids with versatile properties making them promising excipients for enabling formulations for oral drug delivery. Unfortunately, systematic studies on how phospholipid type and content affect oral absorption are rare. Often, only one phospholipid type is used for the formulation development and only one formulation, optimized according to in vitro parameters, is included in oral bioavailability studies. Using this approach, it is unclear if a certain in vitro parameter is predictive for the in vivo performance. In this study, a labor-saving in vitro permeation screening method was combined with a pharmacokinetic study in rats to for the first time systematically compare two types of phospholipid-based solid dispersions. The dispersions contained the drug celecoxib and monoacyl or diacyl phosphatidylcholine at different drug-to-phospholipid ratios. The in vitro screening revealed: 1) none of the formulations with high phospholipid content increased permeation, 2) phospholipid content was negatively correlated with permeation, and 3) mono and diacyl-phosphatidylcholine formulations performed equally. The pharmacokinetic study revealed: 1) At low phospholipid content absorption was enhanced, 2) phospholipid content was negatively correlated with absorption, and 3) monoacyl and diacyl phosphatidylcholine formulations performed equally. Apart from the reference (suspension), the in vitro permeation screening thus predicted the formulations in vivo performance.

Successful oral delivery of fexofenadine hydrochloride by improving permeability via phospholipid complexation

The present work aimed to enhance liposolubility along with intestinal permeability of BCS class III drug fexofenadine (FEX) via phospholipid complexation strategy in order to improve its oral bioavailability. This work demonstrated the minimized P-gp efflux and augmented absorption of FEX when fabricated as phospholipid complex. The fexofenadine-phospholipid complex (FEX-PLC) was prepared using widely used solvent evaporation method. Among three phospholipids, Phospholipon® 90 H was screened out for further studies due to high drug content and physical form. The FTIR spectra demonstrated the disappearance of characteristic peaks of FEX which could be attributed to shielding by phospholipid due to molecular interactions between FEX and phospholipid. The differential scanning calorimetry (DSC) and powder X-ray diffractometry (PXRD) revealed the amorphous state of FEX in the complex. The partition coefficient study indicated the increased in lipophilicity which can further be correlated with 1.85 ± 0.850 fold enhancement in intestinal permeability of FEX-PLC in comparison to FEX in Caco-2 permeability assay. Furthermore, efflux ratio of FEX was decreased significantly from 4.04 (FEX) to 1.34 (FEX-PLC) which indicated inhibition of P-gp efflux of FEX. The in vivo evaluation in Wistar rats presented 3.38 fold increment in oral bioavailability of FEX-PLC as compared to FEX. In summary, the phospholipid complexation demonstrated as a simple and promising approach to tackle oral bioavailability hurdles of BCS class III drugs and convert them to BCS class I drugs.

Polymer/lipid interplay in altering in vitro supersaturation and plasma concentration of a model poorly soluble drug

Supersaturation drug delivery system (SDDS) based on amorphous solid dispersion (ASD) is a widely used strategy to improve oral absorption of poorly water-soluble drugs by achieving a supersaturated state where drug concentration is significantly higher than drug solubility. However, dissolved drugs tend to recrystallize in gastrointestinal (GI) tract if without effective stabilizing excipients. In this paper, well-recognized polymer (polyvinylpyrrolidone, PVP) and lipid (phosphatidylcholine, PC) excipients are combined as ASD carrier, aiming at investigating the effects on evolution of in vitro supersaturation and in vivo plasma concentration of a model poorly soluble drug indomethacin (IND). Fundamental aspects including polymer/lipid composition ratio, drug loading (DL) degree and administration dose were investigated. The in vitro dissolution profiles of ASDs were assessed by supersaturation degree, duration, maximum achievable drug concentration and dose-normalized efficiency, and correlated with in vivo pharmacokinetic data. Results showed that both in vitro and in vivo concentration-time profiles of IND were significantly varying with abovementioned factors. Solution viscosity, solid-state properties and morphology of ASDs were related to the results. This study revealed fundamental mechanisms of PVP/PC mixture effect on IND supersaturation and oral bioavailability, demonstrating that polymer/lipid mixture could be used as a promising carrier to alter supersaturation profile and oral bioavailability of SDDS products.

Harnessing the therapeutic potential of anticancer drugs through amorphous solid dispersions

The treatment of cancer is still a major challenge. But tremendous progress in anticancer drug discovery and development has occurred in the last few decades. However, this progress has resulted in few effective oncology products due to challenges associated with anticancer drug delivery. Oral administration is the most preferred route for anticancer drug delivery, but the majority of anticancer drugs currently in product pipelines and the majority of those that have been commercially approved have inherently poor water solubility, and this cannot be mitigated without compromising their potency and stability. The poor water solubility of anticancer drugs, in conjunction with other factors, leads to suboptimal pharmacokinetic performance. Thus, these drugs have limited efficacy and safety when administered orally. The amorphous solid dispersion (ASD) is a promising formulation technology that primarily enhances the aqueous solubility of poorly water-soluble drugs. In this review, we discuss the challenges associated with the oral administration of anticancer drugs and the use of ASD technology in alleviating these challenges. We emphasize the ability of ASDs to improve not only the pharmacokinetics of poorly water-soluble anticancer drugs, but also their efficacy and safety. The goal of this paper is to rationalize the application of ASD technology in the formulation of anticancer drugs, thereby creating superior oncology products that lead to improved therapeutic outcomes.

Nanoconjugation and Encapsulation Strategies for Improving Drug Delivery and Therapeutic Efficacy of Poorly Water-Soluble Drugs

Nanoconjugations have been demonstrated to be a dominant strategy for drug delivery and biomedical applications. In this review, we intend to describe several strategies for drug formulation, especially to improve the bioavailability of poorly water-soluble molecules for future application in the therapy of numerous diseases. The context of current studies will give readers an overview of the conjugation strategies for fabricating nanoparticles, which have expanded from conjugated materials to the surface conjugation of nanovehicles. Moreover, nanoconjugates for theranostics are also discussed and highlighted. Overall, these state-of-the-art conjugation methods and these techniques and applications for nanoparticulate systems of poorly water-soluble drugs will inspire scientists to explore and discover more productive techniques and methodologies for drug development.

Overview of the Manufacturing Methods of Solid Dispersion Technology for Improving the Solubility of Poorly Water-Soluble Drugs and Application to Anticancer Drugs

Approximately 40% of new chemical entities (NCEs), including anticancer drugs, have been reported as poorly water-soluble compounds. Anticancer drugs are classified into biologic drugs (monoclonal antibodies) and small molecule drugs (nonbiologic anticancer drugs) based on effectiveness and safety profile. Biologic drugs are administered by intravenous (IV) injection due to their large molecular weight, while small molecule drugs are preferentially administered by gastrointestinal route. Even though IV injection is the fastest route of administration and ensures complete bioavailability, this route of administration causes patient inconvenience to visit a hospital for anticancer treatments. In addition, IV administration can cause several side effects such as severe hypersensitivity, myelosuppression, neutropenia, and neurotoxicity. Oral administration is the preferred route for drug delivery due to several advantages such as low cost, pain avoidance, and safety. The main problem of NCEs is a limited aqueous solubility, resulting in poor absorption and low bioavailability. Therefore, improving oral bioavailability of poorly water-soluble drugs is a great challenge in the development of pharmaceutical dosage forms. Several methods such as solid dispersion, complexation, lipid-based systems, micronization, nanonization, and co-crystals were developed to improve the solubility of hydrophobic drugs. Recently, solid dispersion is one of the most widely used and successful techniques in formulation development. This review mainly discusses classification, methods for preparation of solid dispersions, and use of solid dispersion for improving solubility of poorly soluble anticancer drugs.

Feasibility of Using Gluconolactone, Trehalose and Hydroxy-Propyl Gamma Cyclodextrin to Enhance Bendroflumethiazide Dissolution Using Lyophilisation and Physical Mixing Techniques

Purpose: Hydrophobic drugs are facing a major challenge in dissolution rate enhancement and solubility in aqueous solutions; therefore, a variety of methods have been used to improve dissolution rate and/or solubility of bendroflumethiazide as a model hydrophobic drug. Methods: In this study, two main methods (physical mixing and lyophilisation) were used with gluconolactone, hydroxyl propyl γ-ccyclodextrin, and trehalose to explore this challenge. Bendroflumethiazide, practically insoluble in water, was mixed with one of the three excipients gluconolactone, hydroxyl propyl γ-cyclodextrin, and trehalose in three different ratios 1:1, 1:2, 1:5. To the best of our knowledge, the dissolution of the drug has not been previously enhanced by using either these methods or any of the used excipients. Samples containing drug and each of the excipients were characterized via dissolution testing, Fourier Transform infra-red spectroscopy, differential scanning calorimetry, and scanning electron microscopy. Results: The used methods showed a significant enhancement in dug dissolution rate; physical mixing significantly, p < 0.05, increased the percentage of the drug released with time; for example, bendroflumethiazide dissolution in distilled water was improved from less than 20% to 99.79% within 90 min for physically mixed drug-cyclodextrin 1:5. The lyophilisation process was enhanced and the drug dissolution rate and the highest drug dissolution was achieved for (drug-gluconolactone 1:1) with 98.98% drug release within 90 min. Conclusions: the physical mixing and freeze drying processes significantly increased the percentage of drug release with time.