Walnut peptide loaded proliposomes with hydroxyapatite as a carrier: Fabrication, environmental stability, and in vitro digestion attribute

To explore the feasibility of hydroxyapatite (HAP) as the carrier for proliposomes and improve the stability of walnut peptides (WPs), WPs-loaded proliposomes (WPs-PROLIPs) with hydroxyapatite (HAP) as the carrier were fabricated, and the physicochemical properties, environmental stability as well as in vitro simulated digestion release performance of the proliposomes were investigated. The proliposomes with HAP possessed smaller particle sizes and higher encapsulation efficiencies than those without HAP. FTIR analysis revealed that hydrogen bonds formed between HAP and phospholipids in the proliposomes. The inclusion of HAP in WPs-PROLIPs led to the improvement of the thermal degradation stability and environmental stabilities of the system. HAP also induced the conversion of free water into bound water in the proliposomes, as evaluated by LF NMR. In addition, proliposomal encapsulation did not affect the antioxidant activity of WPs-PROLIPs and the lateral order of the liposome membrane. Finally, in vitro digestion showed that the addition of HAP endowed the proliposomes with a retarded free fatty acid release effect, which was dependent on the weight ratio of phospholipids to HAP. These results offer opportunities for the use of HAP as a feasible carrier and lyoprotectant for proliposomes encapsulating biopeptides.

Fabrication and characterization of walnut peptides-loaded proliposomes with three lyoprotectants: Environmental stabilities and antioxidant/antibacterial activities

To protect walnut peptides from harsh external environments during their storage and digestion, proliposomes loaded with walnut peptides were fabricated using sucrose, trehalose, and mannitol as carriers and lyoprotectants. The physicochemical properties, environmental stability, antioxidant/antibacterial activities, and digestion in vitro of the proliposomes were evaluated. The freshly prepared liposomes were uniform in size, but the hydrated proliposomes showed a more uneven size distribution. The lyoprotectants helped maintain favorable liposome shape during lyophilization. Alongside the lyoprotectants, the walnut peptides further stabilized the lipid bilayer. Proliposomes encapsulation didn't impact the peptides' antioxidant activity. Furthermore, walnut peptides-loaded proliposomes exhibited antibacterial activity against Escherichia coli and Staphylococcus aureus. The proliposomes were stable during gastric-phase digestion. The lyoprotectants changed the free fatty acid release behaviors of the proliposomes. These characteristics suggest potential applications for proliposomes as effective delivery systems for biopeptides in food stuffs, thereby protecting bioactivities during storage and passage through the gastrointestinal tract.

Preparation, in vitro and in vivo evaluation of isoliquiritigenin-loaded TPGS modified proliposomes

Isoliquiritigenin (ISL) has a great variety of pharmacological effects especially liver cancer therapy, but its poor solubility, bioavailability and liver targeting have limited its clinical use. In order to solve the aforementioned shortcomings, the TPGS-modified proliposomes loaded with ISL (ISL-TPGS-PLP) was prepared in this study. ISL-TPGS-PLP was fabricated via thin-film dispersion method and was characterized by the appearance, particle size, zeta potential and morphology. HPLC was used to evaluate entrapment efficiency (EE), in vitro release and stability of ISL-TPGS-PLP single or combined while appropriate physicochemical parameters were measured with DLS. Meanwhile, the pharmacokinetics and tissue distribution were also studied after oral administration. The results demonstrated that ISL-TPGS-PLP had a mean size of 23.8 ± 0.9 nm, high EE of 97.33 ± 0.40%. More importantly, nearly 90% ISL was released from ISL-TPGS-PLP within 24 h while only 50% was released from ISL suspension. In the pharmacokinetics study, the area under the curve (AUC_0-24h) of ISL-TPGS-PLP was 1.53 times higher than that of ISL suspension. The Tissue distribution study showed that the ISL released from ISL-TPGS-PLP was higher in the liver than the free ISL suspension. Altogether, ISL-TPGS-PLP could ameliorate the ISL solubility, bioavailability and liver targeting ability, suggesting that ISL-TPGS-PLP could serve as a promising nanocarrier for liver cancer therapy.

A novel nanoproliposomes of lercanidipine: Development, in vitro and preclinical studies to support its effectiveness in hypertension therapy

AIM

The aim of the present study was to develop nanoproliposomes of lercanidipine, in order to overcome its poor biopharmaceutical properties and to improve its therapeutic efficacy in treating hypertension.

MAIN METHODS

The nanoproliposomes were prepared using a modified thin-film hydration method, and the formula was optimized by varying the ratio of lipids and the types of cryoprotectants. This optimized formulation was characterized in terms of its particle size, solid-state, drug release, in-situ absorption, in-vivo pharmacokinetics, and in-vivo anti-hypertensive activity in DOCA-salt induced hypertensive rats. Finally, a PK-PD correlation was established in order to understand the clinical implications of the developed novel nanoproliposomes.

KEY FINDINGS

The nanoproliposomes showed a particle size of 174.7nm and an entrapment efficiency of 85.4%. The in-vitro release displayed initial rapid release (19.33%) followed by a sustained release profile, releasing 88.37% of the encapsulated drug. The in-situ studies showed a significant increase in absorption rate across the rat intestinal membrane. The pharmacokinetics of this novel form indicated a 2.75-fold increase in the absolute bioavailability as compared to pure lercanidipine. In addition, the nanoproliposomes were found to be efficient in treating hypertension in DOCA-salt induced hypertensive rats. The PK-PD correlation demonstrated no time lag between effect and exposure, indicating that a direct PK-PD relationship can be expected in the clinic.

SIGNIFICANCE

These findings suggest that nanoproliposomes are promising carriers in improving the oral bioavailability and bioactivity of lercanidipine, and can be an effective therapy in the management of hypertension.

Improvement of oral availability of ginseng fruit saponins by a proliposome delivery system containing sodium deoxycholate

Ginseng fruit saponins (GFS) extracted from the ginseng fruit are the bioactive triterpenoid saponin components. The aim of the present study was to develop a drug delivery system called proliposome using sodium deoxycholate (NaDC) as a bile salt to improve the oral bioavailability of GFS in rats. The liposomes of GFS were prepared by a conventional ethanol injection and formed the solid proliposomes (P-GFS) using spray drying method on mannitol carriers. The formulation of P-GFS was optimized using the response surface methodology. The physicochemical properties of liposome suspensions including encapsulation efficiency, in vitro drug release studies, particle size of the reconstituted liposome were tested. The solid state characterization studies using the method of Field emission-scanning electron microscope (FE-SEM), Fourier transform infrared (FT-IR) and Differential scanning colorimetric (DSC) were tested to study the molecular state of P-GFS and to indicate the interactions among the formulation ingredients. In vitro studies showed a delayed release of ginsenoside Re (GRe). In vivo studies were carried out in rats. The concentrations of GRe in plasma of rats and its pharmacokinetic behaviors after oral administration of GFS, Zhenyuan tablets (commercial dosage form of GFS) and P-GFS were studied using ultra performance liquid chromatography tandem mass spectrometry. It was founded that the GRe concentration time curves of GFS, Zhenyuan tablets and P-GFS were much more different in rats. Pharmacokinetic behaviors of P-GFS showed a second absorption peak on the concentration time curve. The pharmacokinetic parameters of GFS, Zhenyuan tablets, P-GFS in rats were separately listed as follows: T max 0.25 h, C max 474.96 ± 66.06 ng/ml and AUC0-∞ 733.32 ± 113.82 ng/ml h for GFS; T max 0.31 ± 0.043 h, C max 533.94 ± 106.54 ng/ml and AUC0-∞ 1151.38 ± 198.29 ng/ml h for Zhenyuan tablets; T max 0.5 h, C max 680.62 ± 138.051 ng/ml and AUC0-∞ 2082.49 ± 408.33 ng/ml h for the P-GFS. The bioavailability of P-GFS was nearly 284% and 181% of the GFS and Zhengyuan tablets respectively. In conclusion, the proliposomes significantly enhanced the drug bioavailability, absorption in the gastrointestinal tract and decreased its elimination time of GRe in rats and could be selectively applied for oral delivery of GFS.

Insoluble drug delivery strategies: review of recent advances and business prospects

The emerging trends in the combinatorial chemistry and drug design have led to the development of drug candidates with greater lipophilicity, high molecular weight and poor water solubility. Majority of the failures in new drug development have been attributed to poor water solubility of the drug. Issues associated with poor solubility can lead to low bioavailability resulting in suboptimal drug delivery. About 40% of drugs with market approval and nearly 90% of molecules in the discovery pipeline are poorly water-soluble. With the advent of various insoluble drug delivery technologies, the challenge to formulate poorly water soluble drugs could be achieved. Numerous drugs associated with poor solubility and low bioavailabilities have been formulated into successful drug products. Several marketed drugs were reformulated to improve efficacy, safety and patient compliance. In order to gain marketing exclusivity and patent protection for such products, revitalization of poorly soluble drugs using insoluble drug delivery technologies have been successfully adopted by many pharmaceutical companies. This review covers the recent advances in the field of insoluble drug delivery and business prospects.

Single step spray drying method to develop proliposomes for inhalation: a systematic study based on quality by design approach

Quality by Design (QbD) is a systematic approach to develop drug products which includes evaluation of formulation parameters to achieve defined final product quality. In the present study principles of QbD were extended to the preparation, in-vitro and in-vivo performance of rifapentine-loaded proliposomes for pulmonary inhalation where final product needs to comply with specific properties. The rifapentine-loaded proliposomes for the treatment of tuberculosis were prepared in single step by spray drying method and independent variables were optimized using factorial design approach. Contour plots and multiple regression analysis were used to study the effect of selected independent variables on dependent variables. The effect of presence of drug: hydrogenated soya phosphatidylcholine (HSPC) and type of charged lipid in the formulation at three levels were studied on mass median diameter (MMD), liposomal vesicle size, % encapsulation efficiency (% EE), mass median aerodynamic diameter (MMAD) and fine particle fraction (FPF) as critical quality attributes. Optimized formulation (R-LDPI-7) with drug: HSPC ratio of 1:2 and stearyl amine as charged lipid were found to give respirable proliposomes with MMAD of 1.56 ± 0.16 μm and FPF of 92.5 ± 1.5%. Sustained drug release with Higuchi diffusion kinetics was achieved from liposomally encapsulated rifapentine. Pulmonary pharmacokinetics of optimized batch R-LDPI-7 revealed longer retention of drug in lungs with 7 fold increase in both, the mean residence time and t1/2 as compared to R-DPI-0. The study results demonstrated the application of QbD principles and design of experiment (DOE) approach to develop drug encapsulated proliposomes for inhalation by spray drying in single step.