Effect of inorganic mesoporous carriers on 1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol-loaded solid self-emulsifying drug delivery system: Physicochemical characterization and bioavailability in rats

Modification of microenvironmental pH of nanoparticles for enhanced solubility and oral bioavailability of poorly water-soluble celecoxib

This study aimed to develop a novel pH-modified nanoparticle with improved solubility and oral bioavailability of poorly water-soluble celecoxib by modifying the microenvironmental pH. After assessing the impact of hydrophilic polymers, surfactants and alkaline pH modifiers on the drug solubility, copovidone, sodium lauryl sulfate (SLS) and meglumine were chosen. The optimal formulation of solvent-evaporated, surface-attached and pH-modified nanoparticles composed of celecoxib/copovidone/SLS/meglumine at weight ratios of 1:1:0.2:0, 1:0.375:1.125:0 and 1:1:1:0.2:0.02, respectively, were manufactured using spray drying technique. Their physicochemical characteristics, solubility, dissolution and pharmacokinetics in rats were evaluated compared to the celecoxib powder. The solvent-evaporated and pH-modified nanoparticles converted a crystalline to an amorphous drug, resulting in a spherical shape with a reduced particle size compared to celecoxib powder. However, the surface-attached nanoparticles with insignificant particle size exhibited the unchangeable crystalline drug. All of them gave significantly higher solubility, dissolution, and oral bioavailability than celecoxib powder. Among them, the pH-modified nanoparticles demonstrated the most significant improvement in solubility (approximately 1600-fold) and oral bioavailability (approximately 4-fold) compared to the drug powder owing to the alkaline microenvironment formation effect of meglumine and the conversion to the amorphous drug. Thus, the pH-modified nanoparticle system would be a promising strategy for improving the solubility and oral bioavailability of poorly water-soluble and weakly acidic celecoxib.

Rational Design and Development of a Soluble Mesoporous Carrier for the Solidification of a Preconcentrated Self-Nanoemulsion Formulation

The solidification of self-preconcentrated nanoemulsion without changes in nanodroplet formation gains particular consideration due to the interaction between solidified carriers. This work aimed to develop mannitol mesoporous as a soluble carrier for supersaturated self-nanoemulsion (SSNE) using a design of experiment (DoE) approach. The mesoporous carrier was prepared by a spray-drying technique. The type of templating agent (TA) used to form a porous system, the amount of TA, and solid loading in the spray-drying process were studied. Several characterizations were performed for mannitol mesoporous formation, namely, powder X-ray diffraction, thermal analysis, scanning electron microscopy, and surface area analyzer. Solidification of SSNE incorporated into the mesoporous mannitol was carried out, followed by compaction behavior, flowability, and nanodroplet formation. The results revealed several process parameters for preparing the mesoporous mannitol, notably TA, which gained more significant consideration. Solid loading in the mesoporous preparation system reduced the surface area and pore size and did not affect solid SSNE flowability. The amount of TA increased the pore size and volume dramatically as well as the compactibility and flowability. Ammonium carbonate was the preferable TA for preparing the mesoporous carrier, particularly for the nanodroplet formulation process. In addition, synergistic and antagonistic interactions between factors were also observed. The optimized mesoporous carrier was applied for solidification, and there was no difference between SSNE and solid SSNE in the performance of nanodroplet formation.

Preparation of Solid Self-Nanoemulsifying Drug Delivery Systems (S-SNEDDS) by Co-Extrusion of Liquid SNEDDS and Polymeric Carriers-A New and Promising Formulation Approach to Improve the Solubility of Poorly Water-Soluble Drugs

The present study focused on a new formulation approach to improving the solubility of drugs with poor aqueous solubility. A hot melt extrusion (HME) process was applied to prepare drug-loaded solid self-nanoemulsifying drug delivery systems (S-SNEDDS) by co-extrusion of liquid SNEDDS (L-SNEDDS) and different polymeric carriers. Experiments were performed with L-SNEDDS formulations containing celecoxib, efavirenz or fenofibrate as model drugs. A major objective was to identify a polymeric carrier and process parameters that would enable the preparation of stable S-SNEDDS without impairing the release behavior and storage stability of the L-SNEDDS used and, if possible, even improving them further. In addition to commercially available (co)polymers already used in the field of HME, a particular focus was on the evaluation of different variants of a recently developed aminomethacrylate-based copolymer (ModE) that differed in M_w. Immediately after preparation, the L-SNEDDS and S-SNEDDS formulations were tested for amorphicity by differential scanning calorimetry. Furthermore, solubility and dissolution tests were performed. In addition, the storage stability was investigated at 30 °C/65% RH over a period of three and six months, respectively. In all cases, amorphous formulations were obtained and, especially for the model drug celecoxib, S-SNEDDS were developed that maintained the rapid and complete drug release of the underlying L-SNEDDS even over an extended storage period. Overall, the data obtained in this study suggest that the presented S-SNEDDS approach is very promising, provided that drug-loaded L-SNEDDS are co-processed with a suitable polymeric carrier. In the case of celecoxib, the E-173 variant of the novel ModE copolymer proved to be a novel polymeric carrier with great potential for application in S-SNEDDS. The presented approach will, therefore, be pursued in future studies to establish S-SNEDDS as an alternative formulation to other amorphous systems.

Development of Alectinib-Suspended SNEDDS for Enhanced Solubility and Dissolution

Alectinib hydrochloride (ALH), a tyrosine kinase inhibitor, is a practically water-insoluble drug classified as BCS class IV. The present study aimed to develop novel suspended self-nanoemulsifying drug delivery system (Su-SNEDDS) to enhance the solubility and dissolution rate. The Su-SNEDDS was prepared by saturation and suspension of ALH in SNEDDS with ultrasonication energy. According to evaluation by the dispersion test and the results of particle size analysis, the selected SNEDDS composed of Kolliphor HS 15 and Capmul MCM C8 as surfactant and oil, respectively, showed a complete dissolution within 30 min. However, the SNEDDS loaded and solubilized only small amount of ALH (<0.6%, w/w). On the other hand, 10% ALH-loaded Su-SNEDDS containing small and micronized ALH particles of <5 μm had about 20-fold higher ALH-loading% than the SNEDDS and reached a 100% dissolution rate within 30 min in 1% sodium lauryl sulfate (SLS) pH 1.2 buffer. In the dispersion test and microscopic observation, micronized ALH particles in the Su-SNEDDS were readily dispersed in the dissolution medium with spontaneous nanoemulsion formation and instantly solubilized with the aid of SLS. Taken together, our results suggest that the Su-SNEDDS would be a potent oral dosage form to enhance the solubilization and dissolution rate of ALH in a new technological way.

Development and Characterization of Celecoxib Solid Self-nanoemulsifying Drug Delivery Systems (S-SNEDDS) Prepared Using Novel Cellulose-Based Microparticles as Adsorptive Carriers

Self-nanoemulsifying drug delivery systems (SNEDDS) represent an interesting platform for improving the oral bioavailability of poorly soluble lipophilic drugs. While Liquid-SNEDDS (L-SNEDDS) effectively solubilize the drug in vivo, they have several drawbacks, including poor storage stability. Solid-SNEDDS (S-SNEDDS) combine the advantages of L-SNEDDS with those of solid dosage forms, particularly stability. The aim of the present study was to convert celecoxib L-SNEDDS into S-SNEDDS without altering their release behavior. Various commercially available adsorptive carrier materials were investigated, as well as novel cellulose-based microparticles prepared by spray drying from an aqueous dispersion containing Diacel^® 10 and methyl cellulose or gum arabic as a binder prior to their use. Particle size and morphology of the carrier materials were screened by scanning electron microscopy and their effects on the loading capacity for L-SNEDDS were investigated, and comparative in vitro dissolution studies of celecoxib L-SNEDDS and the different S-SNEDDS were performed immediately after preparation and after 3 months of storage. Among the adsorptive carrier materials, the novel cellulose-based microparticles were found to be the most suitable for the preparation of celecoxib S-SNEDDS from L-SNEDDS, enabling the preparation of a solid, stable formulation while preserving the in vitro release performance of the L-SNEDDS formulation.

Effects of different physicochemical characteristics and supersaturation principle of solidified SNEDDS and surface-modified microspheres on the bioavailability of carvedilol

In this study, a solidified self-nanoemulsifying drug delivery system (solidified SNEDDS) and surface-modified microspheres were developed for enhancing the oral bioavailability of carvedilol. Based on the aqueous solubility test, liquid SNEDDS was composed of Peceol™ (oil), Tween® 80 (surfactant), and Labrasol® (co-surfactant) at a weight ratio of 25/50/25, generating the smallest nanoemulsion droplet size. Then, carvedilol was added to liquid SNEDDS and spray-dried with Aerosil® to fabricate the solidified SNEDDS. Surface-modified microspheres were manufactured using copovidone (polymer) and Tween® 80 (surfactant) according to aqueous solubility test results. The proper ratio of copovidone and Tween® 80 was determined based on the solubility and dissolution test. Both prepared formulations and carvedilol powder were compared using four different criteria: physicochemical characteristics, solubility, dissolution, and oral bioavailability. For solidified SNEDDS, carvedilol was encapsulated in liquid SNEDDS and absorbed to the Aerosil® surface, leading to the conversion from a crystalline to an amorphous state. However, the drug maintained its crystal form in the surface-modified microspheres. Round and even-sized particles were attached to the rough surfaces of drug, suggesting that hydrophilic carriers adhered to the hydrophobic drug. All formulations significantly improved drug solubility, dissolution, plasma concentrations, C_max, and AUC compared to carvedilol powder. The parameters were ranked in the following order: solidified SNEDDS > surface-modified microspheres > carvedilol powder. As a result, different solubility-increasing mechanisms provided differences in performance. For carvedilol, the formation of a nano-emulsion in solidified SNEDDS resulted in an efficient supersaturated state, leading to improved solubility (~6.1 fold), dissolution (~1.8 fold), and oral bioavailability (~1.4 fold) that was superior to the hydrophilic microenvironment in surface-modified microspheres.

Comparative study between high-pressure homogenisation and Shirasu porous glass membrane technique in sildenafil base-loaded solid SNEDDS: Effects on physicochemical properties and in vivo characteristics

The purpose of this study was to compare two types of emulsification techniques in a solid self-nanoemulsifying drug delivery system (SNEDDS); high-pressure homogenisation (HPH) and Shirasu porous glass membrane (SPG). Those two emulsification processes enhanced the solubility, dissolution and oral bioavailability of poorly water-soluble sildenafil base (SB) by producing fine and well-dispersed nanoemulsion droplet. The liquid SNEDDS consisting of Labrasol/Transcutol HP/coconut oil at the weight of 72/18/10, gave the smallest emulsion droplet size among the prepared liquid SNEDDS formulations. Then, the SB-loaded liquid SNEDDS was dissolved in the deionised water and applied to HPH or SPG techniques. Aerosil 200 was suspended as a mesoporous carrier and spray-dried, producing an SB-loaded solid SNEDDS. The emulsion droplet size, solubility and dissolution of each emulsification process were compared to the solid SNEDDS fabricated without any treatment of additional emulsification. Moreover, the physicochemical properties of all formulations were compared. The crystalline state of the drug in all products was converted to the amorphous state. The solid SNEDDS, subjected to HPH technique, provided fine and well-dispersed nanoemulsion. Additionally, it increasingly improved the drug solubility and dissolution as compared to the others, including SB powder, non-treated (NT) and SPG. Furthermore, it gave improved C_max and increased AUC compared to SB powder and SPG, indicating HPH enhanced the oral bioavailability of SB the most. Thus, this solid SNEDDS with HPH would be strongly suggested as an oral SB-loaded pharmaceutical product.

Comparison of 1-Palmitoyl-2-Linoleoyl-3-Acetyl-Rac-Glycerol-Loaded Self-Emulsifying Granule and Solid Self-Nanoemulsifying Drug Delivery System: Powder Property, Dissolution and Oral Bioavailability

The main objective of this study was to compare the powder property, dissolution and bioavailability of 1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol (PLAG)-loaded self-emulsifying granule system (SEGS) and solid self-nanoemulsifying drug delivery system (SNEDDS). Various SEGS formulations were prepared, and the effect of surfactant and binder on the drug solubility in them, leading to selecting sodium lauryl sulphate (SLS) and hydroxyl propyl methyl cellulose (HPMC). The SEGS and SNEDDS were prepared with PLAG/SLS/HPMC/calcium silicate/microcrystalline cellulose at the weight ratio of 1:0.25:0.1:0.5:3 employing the fluid bed granulation and spray-drying technique, respectively. Their powder properties were compared in terms of flow ability, emulsion droplet size, scanning electron microscopy, and powder X-ray diffraction. Furthermore, the solubility, dissolution, and oral bioavailability in rats of the SEGS were assessed in comparison with the SNEDDS. The SEGS and SNEDDS enhanced the solubility of the drug approximately 36- and 32-fold as compared with the drug alone; but they had no differences. The crystalline drug may exist in both the calcium silicate and microcrystalline cellulose (MCC) in the SEGS, but only in the calcium silicate in the SNEDDS. The SEGS had considerably improved the flow ability (Hausner ratio, 1.23 vs. 1.07; Carr index, 19.8 vs. 43.5%) and drug dissolution as compared with the SNEDDS. The SEGS and SNEDDS with double peak profiles, unlike the single peak of drug alone, showed a significantly higher plasma concentration and area under the curve (AUC), as compared with drug alone. Although they were not significantly different, the SEGS gave higher AUC than did the SNEDDS, suggesting its enhanced oral bioavailability of PLAG. Thus, the SEGS could be used as a powerful oral dosage form to improve the flow ability and oral bioavailability of PLAG, an oily drug.