Lacidipine self-nanoemulsifying drug delivery system for the enhancement of oral bioavailability

Metformin Hydrochloride Loaded Mucoadhesive Microspheres and Nanoparticles for Anti-Hyperglycemic and Anticancer Effects Using Factorial Experimental Design

Background

Metformin hydrochloride (HCl) microspheres and nanoparticles were formulated to enhance bioavailability and minimize side effects through sustained action and optimized drug-release characteristics. Initially, the same formulation design with different ratios of metformin HCl and Eudragit RSPO was used to formulate four batches of microspheres and nanoparticles using solvent evaporation and nanoprecipitation methods, respectively.

Methods

The produced formulations were evaluated based on particle size and shape (particle size distribution (PSD), scanning electron microscope (SEM)), incompatibility (differential scanning calorimetry (DSC), Fourier-transform infrared (FTIR)), drug release pattern, permeation behavior, in vivo hypoglycemic effects, and in vitro anticancer potential.

Results

Compatibility studies concluded that there was minimal interaction between metformin HCl and the polymer, whereas SEM images revealed smoother, more spherical nanoparticles than microspheres. Drug release from the formulations was primarily controlled by the non-Fickian diffusion process, except for A1 and A4 by Fickian, and B3 by Super case II. Korsmeyer-Peppas was the best-fit model for the maximum formulations. The best formulations of microspheres and nanoparticles, based on greater drug release, drug entrapment, and compatibility characteristics, were attributed to the study of drug permeation by non-everted intestinal sacs, in vivo anti-hyperglycemic activity, and in vitro anticancer activity.

Conclusion

This study suggests that the proposed metformin HCl formulation can dramatically reduce hyperglycemic conditions and may also have anticancer potential.

A Comprehensive Insight on Self Emulsifying Drug Delivery Systems

BACKGROUND

The oral route is a highly recommended route for the delivery of a drug. But most lipophilic drugs are difficult to deliver via this route due to their low aqueous solubility. Selfemulsifying drug delivery systems (SEDDS) have emerged as a potential approach of increasing dissolution of a hydrophobic drug due to spontaneous dispersion in micron or nano sized globules in the GI tract under mild agitation.

OBJECTIVE

The main motive of this review article is to describe the mechanisms, advantages, disadvantages, factors affecting, effects of excipients, possible mechanisms of enhancing bioavailability, and evaluation of self-emulsifying drug delivery systems.

RESULTS

Self emulsifying systems incorporate the hydrophobic drug inside the oil globules, and a monolayer is formed by surfactants to provide the low interfacial tension, which leads to improvement in the dissolution rate of hydrophobic drugs. The globule size of self-emulsifying systems depends upon the type and ratio of excipients in which they are used. The ternary phase diagram is constructed to find out the range of concentration of excipients used. This review article also presents recent and updated patents on self-emulsifying drug delivery systems. Self-emulsifying systems have the ability to enhance the oral bioavailability and solubility of lipophilic drugs.

CONCLUSION

This technique offers further advantages such as bypassing the first pass metabolism via absorption of drugs through the lymphatic system, easy manufacturing, reducing enzymatic hydrolysis, inter and intra subject variability, and food effects.

An Industrial Procedure for Pharmacodynamic Improvement of Metformin HCl via Granulation with Its Paracellular Pathway Enhancer Using Factorial Experimental Design

Background

Sorbitan monostearate is a surfactant used in the food industry. It was proved as a penetration enhancer to metformin HCl via a paracellular pathway. It is solid at room temperature and has a low melting point. Therefore, it was selected, as a granulating agent for metformin HCl.

Methods

Multi-level factorial design was applied to determine the optimized formula for industrial processing. The selected formulations were scanned using an electron microscope. Differential scanning calorimetry was used to ascertain the crystalline state of a drug. A modified non-everted sac technique, suggested by the authors, was used to evaluate the in vitro permeation enhancement of the drug. To simulate the emulsification effect of the bile salt, a tween 80 was added to the perfusion solution. As a pharmacodynamic marker, blood glucose levels were measured in diabetic rats.

Results

The results showed that drug permeability increases in the presence of tween 80. Drug permeability from granules increased than that of the pure drug or pure drug with tween 80. The prepared granules decreased blood glucose levels of diabetic rats than the pure drug and drug plus tween 80. There was an excellent correlation between the results of the drug permeation percent in vitro and the dropping of blood glucose level percent in vivo.

Conclusion

Improving the drug permeation and consequently, the drug pharmacodynamic effect in addition to an excellent micromeritics property of the prepared drug granules showed the dual enhancement effect of the suggested industrial procedure. Therefore, we suggest the same industrial procedure for other class III drugs.

Development and optimization of drug-loaded nanoemulsion system by phase inversion temperature (PIT) method using Box-Behnken design

OBJECTIVE

The objective of the present investigation was to develop a stable and optimized drug-loaded nanoemulsion system using the phase inversion temperature (PIT) method.

SIGNIFICANCE

The PIT method has been widely used for the development of food-grade nanoemulsion systems. For the first time, a simple and cost-effective, PIT method was used for the development of a stable drug-loaded nanoemulsion system.

METHODS

Box-Behnken experimental design was used for the development of an optimized drug-loaded nanoemulsion system by the PIT method. The independent variables were optimized for responses by using the desirability function. The hydrophobic drug, benidipine was used as a modal drug. Optimized oil phase (blend of long-chain triglycerides oil, medium-chain triglycerides oil and essential oil) was used for the development of oil in water (O/W) nanoemulsion system.

RESULTS

Optimum nanoemulsion formulation was stable, transparent and contained 50% of oil to surfactant percentage with a droplet size of 96.57 ± 1.61 nm. The optimum formulation also showed higher in-vitro drug diffusion from dialysis membrane as compared to the marketed formulation. Nanoemulsion droplets were observed as spherical in the transmission electron microscopy (TEM) images. Box-Behnken statistical analysis revealed that all the independent variables had a significant impact on characteristics of nanoemulsion and the predicated value of independent variables was found to be valid.

CONCLUSION

It was concluded that the PIT method produces a stable and efficient drug-loaded nanoemulsion system. Further, the optimized oil phase can be used as an alternative to costly, commercial medium-chain triglycerides (MCT) oils, for the development of a stable nanoemulsion system.

Investigating the potential of utilizing glycerosomes as a novel vesicular platform for enhancing intranasal delivery of lacidipine

Lacidipine is a potent dihydropyridine calcium channel blocker used for management of hypertension and atherosclerosis. The drug has low and fluctuating oral bioavailability owing to its extensive hepatic first-pass metabolism and reduced water solubility. Accordingly, this work aimed at overcoming the aforementioned challenges through the formulation of intranasal nano-sized lacidipine glycerosomes. Box-Behnken was successfully employed for the formulation and in vitro optimization of the glycerosomes. Statistical analysis revealed that cholesterol concentration exhibited a significant effect on the vesicle size, while Phospholipon® 90G and glycerol concentrations exhibited significant effects on both entrapment efficiency and deformability index. The optimized formulation showed spherical shape, good deformability, vesicular size of 220.25 nm, entrapment efficiency of 61.97%, and enhanced ex vivo permeation by 3.65 fold compared to lacidipine suspension. Confocal laser scattering microscope revealed higher penetration depth via nasal mucosa for rhodamine labelled glycerosomes (up to 60 µm) in comparison to rhoadamine dye solution (26 µm). In addition, the optimized lacidipine glycerosomes caused significant reduction in methylprednisolone acetate-induced hypertension in rats for up to 24 h in comparison to oral drug suspension. Histopathological assessment showed intact nasal mucosal epithelial lining with no signs of inflammation or necrosis confirming the safety and tolerability of the proposed glycerosomes. The declared results highlights the potential of utilizing the proposed glycerosomes as safe and effective platform for intranasal delivery of lacidipine.

Application of Box–Behnken design and desirability function in the development and optimization of self-nanoemulsifying drug delivery system for enhanced dissolution of ezetimibe

Background

This study is focused on developing and optimizing a self-nanoemulsifying drug delivery system (SNEDDS) of BCS class II drug (ezetimibe) through Box–Behnken design (BBD) and desirability function for enhanced dissolution.

Pseudoternary phase diagrams were created by taking oil (Peceol), surfactant (Tween80), and co-surfactant (Transcutol-P) and the concentration ranges were identified for generating BBD. The composition of ezetimibe-SNEDDS was optimized through various response variables viz. globule size (Y1), %transmittance (Y2), self-emulsification time (Y3), dissolution after 5 min and 40 min (Y4, Y5). Optimized formulation was characterized for various physicochemical properties.

Results

Pseudoternary phase diagram having maximum nano-emulsification area was selected to formulate SNEDDS. Derived polynomial equation and model graphs were exercised to investigate the impact of formulation variables on the responses. Significant effect of formulation composition on the responses was observed (p < 0.05). The formulation with least oil (10%) and high surfactant (60%) exhibited low globule size (24.4 ± 2.07 nm), low emulsification time (55 s) but high %transmittance (101.2%) and drug release (49.21% after 5 min; 95.27% after 40 min). Based on the desirability function, the optimized formulation was selected and reformulated. The optimized formulation (FF1) was found to be uniform, stable, and showed similar observed and predicted responses.

Conclusion

The potential of SNEDDS in improving the dissolution profile of weakly soluble drug and the applicability of BBD with desirability function in optimizing a SNEDD formulation has made it possible to identify the impact of various independent variables on optimization of the formulation for better responses.

Self-microemulsifying Drug Delivery System for Problematic Molecules: An Update

BACKGROUND

The poor bioavailability of a problematic molecule is predominantly due to its high lipophilicity, low solubility in gastric fluids and/or high fist pass metabolism. Self microemulsifying drug delivery system (SMEDDS), a lipidic type IV nano-formulation has been of interest in the field of pharmaceutical research due to its potential for tailoring the physicochemical properties of pharmaceutical molecules.

METHODS

This review provides insights on various recent innovations and reports from the past seven years (2012-2019) of self-emulsifying formulations for the delivery of various types of poorly soluble drugs, phytoconstituents and high molecular peptides and gives exhaustive details of the outcome of the endeavors in this field.

RESULTS

Various types of innovative formulations have been molded from SMEDDS like selfemulsifying powders, granules, tablets, pellets, eutectic and cationic formulations. Till date, many research reports and patents have been filed on self-emulsifying dosage forms and many formulations have gained US-FDA approvals which are summarized in the review article.

CONCLUSION

This review content highlighted the increasing scope of SMEDDS in augmenting the physiochemical properties of an API, the variegated formulation types and the attributes of API that can be improved by SMEDD based formulations.

Self-emulsifying drug–delivery systems modulate P-glycoprotein activity: role of excipients and formulation aspects

Self-emulsifying drug–delivery systems (SEDDS) have been widely employed to ameliorate the oral bioavailability of P-glycoprotein (P-gp) substrate drugs and to overcome multidrug resistance in cancer cells. However, the role of formulation aspects in the reduced P-gp activity is not fully understood. In this review, we first explore the role of various SEDDS excipients in the reduced P-gp activity with the main emphasis on the effective excipient concentration range for excipient-mediated modulation of P-gp activity and then we discuss the synergistic effect of various formulation aspects on the excipient-mediated modulation of P-gp activity. This review provides an approach to develop a rationally designed SEDDS to overcome P-gp-mediated drug efflux.

In Vivo Fate of Biomimetic Mixed Micelles as Nanocarriers for Bioavailability Enhancement of Lipid-Drug Conjugates

The transformation of lipid-based nanovehicles into mixed micelles (MMs) upon lipolysis plays an indispensable role in enhancement of the oral bioavailability of poorly water-soluble drugs. Therefore, this study employs biomimetic MMs as functional vehicles to enhance the oral bioavailability of the lipid conjugates of a model drug silybin. The main objective is to explore the in vivo fate and underlying mechanisms of facilitated absorption by MMs. Pharmacokinetics in rats indicate bioavailability enhancement by 7-9 folds as compared to a fast-release silybin solid dispersion formulation. Confocal laser scanning microscopy reveals evidence of cellular uptake of integral MMs into the cytoplasm of both Caco-2 and Caco-2/HT29-MTX coculture cells lines. The recovery of a definite amount of prototype silybin but negligible or traces of lipid-silybin conjugates from the cells, as well as the limited trans-monolayer transport, confirms fast disruption of MMs and fast degradation of the conjugates as well. The MMs survive the gastrointestinal environment with relatively high integrity for about 4 h, and are found accumulating in intestinal villi surface layers in higher density but in lower density to the basolateral tissues. By scanning the organs, a small amount of integral MMs are observed to distribute mainly to the livers with peak time around 4-8 h. The total amount of lymphatic absorption monitored by cannulation is negligible. It is concluded that biomimetic MMs might be taken up by enterocytes and be digested there to release the prototype drug, which is further transported to the circulation, and only a limited amount of integral MMs could be absorbed into the circulation.