Development of a Multifunctional Oral Dosage Form via Integration of Solid Dispersion Technology with a Black Seed Oil-Based Self-Nanoemulsifying Drug Delivery System

Layer-by-Layer Engineering of Black Seed Oil Based SNEDDSs (BSO-SNEDDSs): Optimizing Chemical Stability and Bioavailability in Ramipril Formulations

Purpose

The inherent chemical instability of ramipril (RMP) can lead to reduced therapeutic efficacy and safety, emphasizing the need for innovative formulation strategies for increased stability and bioavailability. This study aims to develop RMP-loaded liquid and solid self-nanoemulsifying formulations (SNEDDSs) that incorporate cardioprotective black seed oil (BSO) as a natural source of bioactive thymoquinone (THQ) for comprehensive chemical stability and pharmacokinetic evaluation.

Methods

A systematic approach was employed to transform liquid SNEDDSs into both single-layer (Single-SNEPs) and multilayer (Multi-SNEPs) self-nanoemulsifying pellets through fluid bed coating technology. Extensive characterization encompassing morphological analysis, dissolution studies, chemical stability assessments, and pharmacokinetic profiling, was conducted.

Results

In vitro dissolution studies demonstrated that the multilayered 5L-SNEPs formulation exhibited the highest dissolution efficiency compared with that of pure RMP (p > 0.05) and pure THQ (P < 0.05). Notably, the 5-layer pellets (5L-SNEPs) exhibited superior chemical stability of RMP (p < 0.05) compared with the liquid SNEDDS and other pellet variants. In-vivo pharmacokinetic analysis in rats revealed that liquid SNEDDS showed a numerically greater maximum plasma concentration (Cmax = 106 ± 34 ng/mL) and area under the curve (AUC = 454 ± 265 ng·h/mL) compared to pure RMP (Cmax = 90 ± 17 ng/mL; AUC = 308 ± 213 ng·h/mL), indicating a 1.5-fold higher AUC from the liquid SNEDDS. However, the difference was not statistically significant. Interestingly, 5L-SNEPs resulted in the lowest RMP exposure among the tested formulations, with a Cmax of 60 ± 18 ng/mL and an AUC of 155 ± 59 ng·h/mL, although the differences were not statistically significant compared to the other groups. The time to maximum concentration (Tmax) was 0.8 hours for liquid SNEDDS, 0.6 hours for the 5L-SNEPs, and 0.5 hours for pure RMP.

Conclusion

While liquid SNEDDSs exhibit promisingly greater oral bioavailability than crystalline drugs do, the performance of multilayer solid SNEDDSs necessitates further refinement. Nonetheless, this comprehensive investigation establishes a robust foundation for continued research on multifunctional bioactive oil-based SNEDDSs to enhance the bioavailability of drugs with limited water solubility.

Physical isolation strategy in multi-layer self-nanoemulsifying pellets: Improving dissolution and drug loading efficiency of ramipril

BACKGROUND AND PURPOSE

Liquid self-nanoemulsifying drug delivery systems (SNEDDS) face challenges related to stability, handling, and storage. In particular, lipophilic and unstable drugs, such as ramipril (RMP) and thymoquinone (THQ), face challenges in oral administration due to poor aqueous solubility and chemical instability. This study aimed to develop and optimize multi-layer self-nanoemulsifying pellets (ML-SNEP) to enhance the stability and dissolution of ramipril (RMP) and thymoquinone (THQ).

METHODS

Liquid SNEDDS containing RMP and black seed oil (as a natural source of THQ) were prepared and characterized. The fluid-bed coating process was optimized by evaluating critical parameters such as inlet temperature, product temperature, air flow rate, atomizing air pressure, spray rate, and column height. Single-layer (SL-SNEP) and multi-layer (ML-SNEP) self-nanoemulsifying pellets were developed by applying various functional layers onto nonpareil sugar spheres. The pellets were characterized using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and in vitro dissolution studies.

RESULTS

Optimized fluid-bed coating parameters resulted in high coating recovery (>80%) and excellent mono-pellet percentages (≥97%). SEM analysis revealed well-defined, completely solidified layers in ML-SNEP. DSC and XRD studies suggested RMP amorphization. In vitro dissolution studies showed >86% RMP and THQ release within 60 minutes for both SL-SNEP and ML-SNEP. The physical isolation strategy significantly improved drug loading efficiency, with ML-SNEP showing 109% RMP loading efficiency compared to 55% in SL-SNEP. The addition of moisture sealing and anti-adherent layers had no negative impact on drug release, with SNEP-5L (including the anti-adherent layer) showing higher dissolution efficiency for both RMP and THQ.

CONCLUSION

This study successfully developed and optimized ML-SNEP as a novel approach for enhancing the stability and release of RMP and THQ. The physical isolation strategy was a key approach in enhancing drug loading efficiency while preserving the advantageous dissolution properties of liquid SNEDDS. This approach offers valuable insights for developing advanced oral drug delivery systems for poorly water-soluble and labile drugs.

Optimization of Glibenclamide Loaded Thermoresponsive SNEDDS Using Design of Experiment Approach: Paving the Way to Enhance Pharmaceutical Applicability

Thermoresponsive self-nanoemulsifying drug delivery systems (T-SNEDDS) offer a promising solution to the limitations of conventional SNEDDS formulations. Liquid SNEDDS are expected to enhance drug solubility; however, they are susceptible to leakage during storage. Even though solid SNEDDS offers a solution to this storage instability, they introduce new challenges, namely increased total dosage and potential for drug trapping within the formulation. The invented T-SNEDDS was used to overcome these limitations and improve the dissolution of glibenclamide (GBC). Solubility and transmittance studies were performed to select a suitable oil and surfactant. Design of Experiments (DoE) software was used to study the impact of propylene glycol and Poloxamer 188 concentrations on measured responses (liquefying temperature, liquefying time, and GBC solubility). The optimized formulation was subjected to an in vitro dissolution study. The optimized T-SNEDDS consisted of Kolliphor EL and Imwitor 308 as surfactants and oil. The optimized propylene glycol and Poloxamer 188 concentrations were 13.7 and 7.9% w/w, respectively. It exhibited a liquefying temperature of 35.0 °C, a liquefying time of 119 s, and a GBC solubility of 5.51 mg/g. In vitro dissolution study showed that optimized T-SNEDDS exhibited 98.8% dissolution efficiency compared with 2.5% for raw drugs. This study presents a promising approach to enhance pharmaceutical applicability by resolving the limitations of traditional SNEDDS.

Lipid-Based Nanoformulations for Drug Delivery: An Ongoing Perspective

Oils and lipids help make water-insoluble drugs soluble by dispersing them in an aqueous medium with the help of a surfactant and enabling their absorption across the gut barrier. The emergence of microemulsions (thermodynamically stable), nanoemulsions (kinetically stable), and self-emulsifying drug delivery systems added unique characteristics that make them suitable for prolonged storage and controlled release. In the 1990s, solid-phase lipids were introduced to reduce drug leakage from nanoparticles and prolong drug release. Manipulating the structure of emulsions and solid lipid nanoparticles has enabled multifunctional nanoparticles and the loading of therapeutic macromolecules such as proteins, nucleic acid, vaccines, etc. Phospholipids and surfactants with a well-defined polar head and carbon chain have been used to prepare bilayer vesicles known as liposomes and niosomes, respectively. The increasing knowledge of targeting ligands and external factors to gain control over pharmacokinetics and the ever-increasing number of synthetic lipids are expected to make lipid nanoparticles and vesicular systems a preferred choice for the encapsulation and targeted delivery of therapeutic agents. This review discusses different lipids and oil-based nanoparticulate systems for the delivery of water-insoluble drugs. The salient features of each system are highlighted, and special emphasis is given to studies that compare them.

Self-Nanoemulsifying Drug Delivery System Combined with a Polymeric Amorphous System of Glibenclamide for Enhanced Drug Dissolution and Stability

Self-nanoemulsifying drug delivery systems (SNEDDS) have been widely applied to improve the dissolution and bioavailability of hydrophobic medications like glibenclamide (GB). However, the acid liability of GB limits its loading in SNEDDS formulation owing to the expected drug degradation. The present study investigated the ability of a polymeric amorphous system (PAS) to amorphize raw GB and facilitate its integration within dispersed SNEDDS. Liquid-SNEDDS (L-SNEDDS), solid-SNEDDS (S-SNEDDS), and combined systems (SNEDDS + PAS) were prepared for this purpose. The physicochemical properties of the prepared formulations were examined using a zeta-sizer, SEM, DSC, PXRD, and dissolution apparatus. In addition, GB integrity within formulations following incubation in a stability chamber was also investigated. The prepared formulations were able to be dispersed within the nanosize range. SEM, DSC, and PXRD showed that freeze-drying (FD) was superior to the microwave (MW) method in GB amorphization. Even though L-SNEDDS and S-SNEDDS were able to increase the dissolution efficiency (DE) of GB, drug degradation was observed. However, PAS prepared using FD was able to increase the DE of GB from 2.5% to 84.2% and protect the drug from chemical degradation. The present study revealed that a combined system (SNEDDS + PAS) is a promising approach to enhance the stability of acid-labile drugs and facilitate the integration of amorphous drugs within a dispersed SNEDDS formulation.

Enhanced dissolution rates of glibenclamide through solid dispersions on microcrystalline cellulose and mannitol, combined with phosphatidylcholine

OBJECTIVE

This study aimed to investigate the impact of physical solid dispersions of spray-dried glibenclamide (SG) on the surface of microcrystalline cellulose (MC) and mannitol (M) surfaces, as well as their combination with phosphatidylcholine (P), on enhancing the dissolution rate of glibenclamide (G).

METHODS

Solid dispersions were prepared using varying proportions of 1:1, 1:4, and 1:10 for SG on the surface of MC (SGA) and M (SGM), and then combined with P, in a proportion of 1:4:0.02 using spray drying. The particle size, specific surface area, scanning electron microscopy (SEM), X-ray diffraction (XRD), and dissolution rate of SGA and SGM were characterized.

RESULTS

SEM analysis revealed successful adhesion of SG onto the surface of the carrier surfaces. XRD showed reduced crystalline characteristic peaks for SGA, while SGM exhibited a sharp peaks pattern. Both SGA and SGM demonstrated higher dissolution rates compared to SG and G alone. Furthermore, the dissolution rates of the solid dispersions of SG, MC and P (SGAP), and SG, M, and P (SGMP) were sequentially higher than that of SGA and SGM.

CONCLUSIONS

The study suggests that physical solid dispersions of SG on MC and M, along with their combination with P, can effectively enhance the dissolution rate of G. These findings may be valuable in developing of oral solid drug dosage forms utilizing SGA, SGM, SGAP, and SGMP.