Development and evaluation of solid dispersion based rapid disintegrating tablets of poorly water-soluble anti-diabetic drug

Self-microemulsifying drug delivery system-based gastroretentive in situ raft of pazopanib with enhanced solubility and bioavailability

Pazopanib hydrochloride (PZH) is a Biopharmaceutics Classification System class II drug that faces challenges at the formulation forefront including low aqueous solubility (0.043 mg/mL) and poor oral bioavailability (14-39%). The present investigation aimed to develop a self-microemulsifying drug delivery system (SMEDDS) of PZH using a blend of Capryol® 90, Labrasol®, and propylene glycol to improve its solubility. Furthermore, a sustained-release SMEDDS-based gastroretentive floating system was developed and optimized using the Central Composite Design approach of DoE. The optimized SMEDDS-based in situ gelling raft, R-SM-PZH, exhibited minimal floating lag time (3.09 ± 0.8 s), optimal viscosity (1229.4 ± 20.9 cP) and density (0.327 ± 0.15 g/mL) as compared to other formulations under study. Additionally, R-SM-PZH was evaluated for its in vitro dissolution in FaSSGF and FeSSGF, pharmacokinetic profile, and MTT assay (against NCI-H460 lung cancer cells) compared to pure PZH. A 12 h sustained release, three-fold augmentation in dissolution rate and bioavailability, and 15-fold enhancement in cytotoxicity were observed in comparison to pure PZH. Thus, the SMEDDS-based in situ gelling raft presents a promising approach to advancing the developability potential of PZH.

Formulation and Evaluation of pH-Modulated Amorphous Solid Dispersion-Based Orodispersible Tablets of Cefdinir

Cefdinir (CEF) is a semi-synthetic third-generation broad-spectrum oral cephalosporin that exhibits poor solubility at lower pH values. Considering this, pH-modulated CEF solid dispersions (ASDs) were produced by solvent evaporation method employing various hydrophilic carriers and alkalizers. Among different carriers, ASDs produced using PEG 6000 with meglumine as alkalizer were found to significantly increase (p < 0.005) the drug solubility (4.50 ± 0.32 mg/mL) in pH 1.2. Fourier transform infrared spectrophotometry confirmed chemical integrity of CEF while differential scanning calorimetry (DSC) and X-ray diffractometry (XRD) indicated CEF was reduced to an amorphous state in ASD8. Antimicrobial assay performed by well diffusion method against Staphylococcus aureus (MTCC96) and Escherichia coli (MTCC118) demonstrated significantly superior (p < 0.001) efficacy of CEFSD compared to CEF. The porous orodispersible tablets (ODTs) of ASD8 (batch F5) were developed by incorporating ammonium bicarbonate as a subliming agent by direct compression, followed by vacuum drying displayed quick disintegration (27.11 ± 1.96 s) that met compendial norms and near-complete dissolution (93.85 ± 1.27%) in 30 min. The ODTs of ASD8 appear to be a promising platform to mitigate the pH-dependent solubility and dissolution issues associated with CEF in challenging physiological pH conditions prevalent in stomach. Thus, ODTs of ASD8 are likely to effectively manage various infections and avoid development of drug-resistant strains, thereby improving the curing rates.

Molecular insights into the aggregation and solubilizing behavior of biocompatible amphiphiles Gelucire® 48/16 and Tetronics® 1304 in aqueous media

A comparative analysis of the micellar and solubilizing properties of two polyethylene glycol (PEG)-based amphiphilic biocompatible excipients: Gelucire® 48/16 (Ge 48/16) and Tetronics® 1304 (T1304), in the presence and absence of salt, was conducted. As there is a dearth of research in this area, the study aims to shed light on the behavior of these two nonionic surfactants and their potential as nanocarriers for solubilizing pharmaceuticals. Various techniques such as cloud point (CP), dynamic light scattering (DLS), small-angle neutron scattering (SANS), Fourier transform infrared spectroscopy (FT-IR), UV spectrophotometry, and high-performance liquid chromatography (HPLC) were employed. The solubility of quercetin (QCT), a flavonoid with anti-inflammatory, antioxidant, and anti-cancer properties, was evaluated and the interaction between QCT and the micellar system was examined. The analysis revealed the occurrence of strong interactions between QCT and surfactant molecules, resulting in enhanced solubility. It was observed that the micellar size and solubilizing ability were significantly improved in the presence of salt, while the CP decreased. Ge 48/16 exhibited superior performance, with a remarkable increase in the solubility of QCT in the presence of salt, suggesting its potential as an effective nanocarrier for a range of pharmaceutics, and yielding better therapeutic outcomes.

Transdermal Delivery of Glimepiride: A Novel Approach Using Nanomicelle-Embedded Microneedles

Glimepiride (GM) is a hydrophobic drug that dissolves slowly and yields inconsistent clinical responses after oral administration. Transdermal drug delivery (TDD) is an appropriate alternative to oral administration. Microneedles (MNs) offer a promising delivery system that penetrates the skin, while polymeric micelles can enhance the solubility; hence, the combination of both results in high drug bioavailability. This study aims to improve glimepiride's solubility, dissolution rate, and bioavailability by incorporating nanomicelles into MNs for TDD. The nanomicelles formulated with 10% Soluplus® (SP) and 40% GM had a mean particle size of 82.6 ± 0.54, PDI of 0.1 ± 0.01, -16.2 ± 0.18 zeta potential, and achieved a 250-fold increase in solubility. The fabricated pyramid shaped GM-dissolving MNs were thermally stable and had no formulation incompatibility, as confirmed by thermal and FTIR analysis. The in vitro dissolution profile revealed that the GM release from nanomicelles and nanomicelle-loaded DMN was concentration-independent following non-Fickian transport mechanism. Improved pharmacokinetic parameters were obtained with dose of 240 µg as compared to 1 mg of GM oral tablet, in healthy human volunteers. The observed Cmax, Tmax and MRT were 1.56 μg/mL ± 0.06, 4 h, and 40.04 h ± 3.37, respectively. The safety profile assessment indicated that microneedles are safe with no adverse effects on skin or health. This study provides an alternative delivery system for the administration of glimepiride, resulting in improved bioavailability, enhanced patient compliance, and reduced dosing frequency.

In vitro profiling of fenofibrate solid dispersion mediated tablet formulation to treat high blood cholesterol

OBJECTIVE

Fenofibrate (FNF), an anti-hyperlipidemic agent, suffers from poor water solubility (0.000707mg/ml) and belongs to class II drug as per BCS, shows a slow dissolution rate. The current investigation aimed to fabricate a fast-dissolving tablet of FNF (not available in the commercial market) using solid dispersion technique employing Vitamin E-D-α-Tocopheryl polyethylene glycol 1000 succinate (vitamin E TPGS) as molecular biomaterial to enhance dissolution rate and reduce the time required to reach the systemic circulation.

MATERIALS AND METHODS

Firstly, carrier material was selected based on the release study via preparing solid dispersion using the melting method, and prepared solid dispersion was characterized. Secondly, fast-dissolving tablets from solid dispersion were fabricated using the direct compression tool and characterized for X-ray diffraction (XRD) pattern, friability, hardness, content uniformity, weight variation and in vitro disintegration test.

RESULTS

The X-ray diffraction study confirmed the successful formation of solid dispersion using vitamin E TPGS by analyzing the change in physical state. The fabricated solid dispersion exhibited higher drug content than a physical mixture of FNF. An excipient interference study was also performed in methanol and 0.75% w/v sodium lauryl sulphate. It revealed no significant alterations in the absorption peak of FNF as analyzed using UV spectroscopy at 287nm. In addition, water absorption ratio phase solubility and wetting time were also assessed. In -vitro release of FNF from developed tablets was found significantly higher (93.23%±3.11; p<0.001) as compared to prepared compressed tablet of pure FNF (12.21±2.34%). The dissolution rate was also determined, and data were then kept to various kinetic models such as zero-order chemical kinetic, first-order chemical kinetic, Hixon-Crowell and Higuchi chemical kinetic.

CONCLUSION

A complete and sequential in vitro and physicochemical characterization of developed formulation was carried out to set-up improved and effective treatment for high blood cholesterol.

Amalgamation of solid dispersion and melt adsorption techniques for augmentation of oral bioavailability of novel anticoagulant rivaroxaban

The objective of the present study was to evaluate the potential of solid dispersion adsorbate (SDA) to improve the solubility and bioavailability of rivaroxaban (RXN). SDA of RXN was developed by fusion method using PEG 4000 as carrier and Neusilin as adsorbent. A 3² full factorial design was utilized to formulate various SDAs. The selected independent variables were the amount of carrier (X₁) and amount of adsorbent (X₂). The responses measured were the time required for 85% drug release (Y₁) and saturated solubility (Y₂). MTT assay was employed for cytotoxicity studies on Caco-2 cells. In vivo pharmacokinetics and pharmacodynamic evaluations were carried out to assess the prepared SDA. Pre-compression evaluation of SDA suggests the prepared batches (B1-B9) possess adequate flow properties and could be used for compression of tablets. Differential scanning calorimetry and X-ray diffraction data signified the conversion of the crystalline form of drug to amorphous form, a key parameter accountable for improvement in drug dissolution. Optimization data suggests that the amount of carrier and amount of adsorbent significantly (P < 0.05) influence both dependent variables. Post-compression data signifies that the compressibility behavior of prepared tablets was within the official standard limits. A significant increase (P < 0.0001) in the in vitro dissolution characteristics of RXN was noticed in optimized SDA (> 85% in 10 min) as compared to the pure drug, marketed product, and directly compressible tablet. Cytotoxicity studies confirmed the nontoxicity of prepared RXN SDA tablets. RXN SDA tablets exhibited 2.79- and 1.85-fold higher AUC in comparison to RXN suspension and Xarelto tablets respectively indicating improved oral bioavailability. Higher bleeding time and percentage of platelet aggregation noticed with RXN SDA tablets in comparison to RXN suspension further substantiate the efficacy of the prepared formulation. In summary, the results showed the potential of RXN SDA tablets to enhance the bioavailability of RXN and hence can be an alternate approach of solid dosage form for its development for commercial application.

Development and Characterization of Oral Raft Forming In Situ Gelling System of Neratinib Anticancer Drug Using 32 Factorial Design

Neratinib (NTB) is an irreversible inhibitor of pan-human epidermal growth factor receptor (HER-2) tyrosine kinase and is used in the treatment of breast cancer. It is a poorly aqueous soluble drug and exhibits extremely low oral bioavailability at higher pH, leading to a diminishing of the therapeutic effects in the GIT. The main objective of the research was to formulate an oral raft-forming in situ gelling system of NTB to improve gastric retention and drug release in a controlled manner and remain floating in the stomach for a prolonged time. In this study, NTB solubility was enhanced by polyethylene glycol (PEG)-based solid dispersions (SDs), and an in situ gelling system was developed and optimized by a two-factor at three-level (3²) factorial design. It was analyzed to study the impact of two independent variables viz sodium alginate [A] and HPMC K4M [B] on the responses, such as floating lag time, percentage (%) water uptake at 2 h, and % drug release at 6 h and 12 h. Among various SDs prepared using PEG 6000, formulation 1:3 showed the highest drug solubility. FT-IR spectra revealed no interactions between the drug and the polymer. The percentage of drug content in NTB SDs ranged from 96.22 ± 1.67% to 97.70 ± 1.89%. The developed in situ gel formulations exhibited a pH value of approximately 7. An in vitro gelation study of the in situ gel formulation showed immediate gelation and was retained for a longer period. From the obtained results of 3² factorial designs, it was observed that all the selected factors had a significant effect on the chosen response, supporting the precision of design employed for optimization. Thus, the developed oral raft-forming in situ gelling system of NTB can be a promising and alternate approach to enhance retention in the stomach and to attain sustained release of drug by floating, thereby augmenting the therapeutic efficacy of NTB.

Development and characterization of solid dispersion-based orodispersible tablets of cilnidipine

Background

Cilnidipine, a calcium channel blocker, is the first-line drug for hypertension and belongs to Biopharmaceutics Classification System II. To mitigate its extensive first-pass metabolism and improve patient compliance, the present study was performed to develop and characterize solid dispersion-based orodispersible tablets.

Results

The phase solubility study with polyvinyl pyrrolidone 15% has shown a 140-fold increase in solubility. X-ray diffraction and differential scanning calorimetry studies emphasized the conversion of solid dispersion from crystalline to amorphous state. Solid dispersion 3 resulted in 142-fold improvement in solubility, 96% of drug content, and percentage drug release was 71.9% at 60 min. F11 containing crospovidone (10 mg) and sodium starch glycolate (16 mg) in combination at higher concentration as super-disintegrants showed the least disintegration time of 26.6 s. In vitro dissolution results are subjected to statistical analysis and found that the formulation (F11) has shown an increased dissolution rate (88.62% at 10 min), compared to the marketed formulation (83% at 60 min).

Conclusions

Solid dispersion prepared by a solvent evaporation method using PVP as a carrier can be utilized for enhancing the solubility of cilnidipine. The incorporation of super-disintegrants in combination improves the dissolution rate of orodispersible tablets. Further, the study can be substantiated by performing stability and in vivo studies in the future.

Graphical Abstract

Understanding the Effect of Energy Density and Formulation Factors on the Printability and Characteristics of SLS Irbesartan Tablets-Application of the Decision Tree Model

Selective laser sintering (SLS) is a rapid prototyping technique for the production of three-dimensional objects through selectively sintering powder-based layer materials. The aim of the study was to investigate the effect of energy density (ED) and formulation factors on the printability and characteristics of SLS irbesartan tablets. The correlation between formulation factors, ED, and printability was obtained using a decision tree model with an accuracy of 80%. FT-IR results revealed that there was no interaction between irbesartan and the applied excipients. DSC results indicated that irbesartan was present in an amorphous form in printed tablets. ED had a significant influence on tablets’ physical, mechanical, and morphological characteristics. Adding lactose monohydrate enabled faster drug release while reducing the possibility for printing with different laser speeds. However, formulations with crospovidone were printable with a wider range of laser speeds. The adjustment of formulation and process parameters enabled the production of SLS tablets with hydroxypropyl methylcellulose with complete release in less than 30 min. The results suggest that a decision tree could be a useful tool for predicting the printability of pharmaceutical formulations. Tailoring the characteristics of SLS irbesartan tablets by ED is possible; however, it needs to be governed by the composition of the whole formulation.