Pharmacokinetic and pharmacodynamic studies following oral administration of erythropoietin mucoadhesive tablets to beagle dogs

Lipid Horizons: Recent Advances and Future Prospects in LBDDS for Oral Administration of Antihypertensive Agents

The lipid-based drug delivery system (LBDDS) is a well-established technique that is anticipated to bring about comprehensive transformations in the pharmaceutical field, impacting the management and administration of drugs, as well as treatment and diagnosis. Various LBDDSs verified to be an efficacious mechanism for monitoring hypertension systems are SEDDS (self-nano emulsifying drug delivery), nanoemulsion, microemulsions, vesicular systems (transferosomes and liposomes), and solid lipid nanoparticles. LBDDSs overcome the shortcomings that are associated with antihypertensive agents because around fifty percent of the antihypertensive agents experience a few drawbacks including short half-life because of hepatic first-pass metabolism, poor aqueous solubility, low permeation rate, and undesirable side effects. This review emphasizes antihypertensive agents that were encapsulated into the lipid carrier to improve their poor oral bioavailability. Incorporating cutting-edge technologies such as nanotechnology and targeted drug delivery, LBDDS holds promise in addressing the multifactorial nature of hypertension. By fine-tuning drug release profiles and enhancing drug uptake at specific sites, LBDDS can potentially target renin-angiotensin-aldosterone system components, sympathetic nervous system pathways, and endothelial dysfunction, all of which play crucial roles in hypertension pathophysiology. The future of hypertension management using LBDDS is promising, with ongoing reviews focusing on precision medicine approaches, improved biocompatibility, and reduced toxicity. As we delve deeper into understanding the intricate mechanisms underlying hypertension, LBDDS offers a pathway to develop next-generation antihypertensive therapies that are safer, more effective, and tailored to individual patient needs.

Rationale utilization of phospholipid excipients: a distinctive tool for progressing state of the art in research of emerging drug carriers

Phospholipids have a high degree of biocompatibility and are deemed ideal pharmaceutical excipients in the development of lipid-based drug delivery systems, because of their unique features (permeation, solubility enhancer, emulsion stabilizer, micelle forming agent, and the key excipients in solid dispersions) they can be used in a variety of pharmaceutical drug delivery systems, such as liposomes, phytosomes, solid lipid nanoparticles, etc. The primary usage of phospholipids in a colloidal pharmaceutical formulation is to enhance the drug's bioavailability with low aqueous solubility [i.e. Biopharmaceutical Classification System (BCS) Class II drugs], Membrane penetration (i.e. BCS Class III drugs), drug uptake and release enhancement or modification, protection of sensitive active pharmaceutical ingredients (APIs) from gastrointestinal degradation, a decrease of gastrointestinal adverse effects, and even masking of the bitter taste of orally delivered drugs are other uses. Phospholipid-based colloidal drug products can be tailored to address a wide variety of product requirements, including administration methods, cost, product stability, toxicity, and efficacy. Such formulations that are also a cost-effective method for developing medications for topical, oral, pulmonary, or parenteral administration. The originality of this review work is that we comprehensively evaluated the unique properties and special aspects of phospholipids and summarized how the individual phospholipids can be utilized in various types of lipid-based drug delivery systems, as well as listing newly marketed lipid-based products, patents, and continuing clinical trials of phospholipid-based therapeutic products. This review would be helpful for researchers responsible for formulation development and research into novel colloidal phospholipid-based drug delivery systems.

Formulation strategies to improve the efficacy of intestinal permeation enhancers. Adv Drug Deliv Rev 2021;177:113925. [PMID: 34418495 DOI: 10.1016/j.addr.2021.113925]

The use of chemical permeation enhancers (PEs) is the most widely tested approach to improve oral absorption of low permeability active agents, as represented by peptides. Several hundred PEs increase intestinal permeability in preclinical bioassays, yet few have progressed to clinical testing and, of those, only incremental increases in oral bioavailability (BA) have been observed. Still, average BA values of ~1% were sufficient for two recent FDA approvals of semaglutide and octreotide oral formulations. PEs are typically screened in static in vitro and ex-vivo models where co-presentation of active agent and PE in high concentrations allows the PE to alter barrier integrity with sufficient contact time to promote flux across the intestinal epithelium. The capacity to maintain high concentrations of co-presented agents at the epithelium is not reached by standard oral dosage forms in the upper GI tract in vivo due to dilution, interference from luminal components, fast intestinal transit, and possible absorption of the PE per se. The PE-based formulations that have been assessed in clinical trials in either immediate-release or enteric-coated solid dosage forms produce low and variable oral BA due to these uncontrollable physiological factors. For PEs to appreciably increase intestinal permeability from oral dosage forms in vivo, strategies must facilitate co-presentation of PE and active agent at the epithelium for a sustained period at the required concentrations. Focusing on peptides as examples of a macromolecule class, we review physiological impediments to optimal luminal presentation, discuss the efficacy of current PE-based oral dosage forms, and suggest strategies that might be used to improve them.

Intestinal permeation enhancers to improve oral bioavailability of macromolecules: reasons for low efficacy in humans

INTRODUCTION

Intestinal permeation enhancers (PEs) are substances that transiently alter the intestinal epithelial barrier to facilitate permeation of macromolecules with low oral bioavailability (BA). While a number of PEs have progressed to clinical testing in conventional formulations with macromolecules, there has been only low single digit increases in oral BA, irrespective of whether the drug met primary or secondary clinical endpoints.

AREAS COVERED

This article considers the causes of sub-optimal BA of macromolecules from PE dosage forms and suggests approaches that may improve performance in humans.

EXPERT OPINION

Permeation enhancement is most effective when the PE is co-localized with the macromolecule at the epithelial surface. Conditions in the GI tract impede optimal co-localization. Novel delivery systems that limit dilution and spreading of the PE and macromolecule in the small intestine have attempted to replicate promising enhancement efficacy observed in static drug delivery models.

Lipid-Based Nanosystem As Intelligent Carriers for Versatile Drug Delivery Applications

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The contemporary drug discovery research shows that most of the drug candidates are highly potent, but showing poor aqueous solubility leads a variety of challenges for formulation scientists to develop a suitable formulation to improve the systemic bioavailability of such drugs. Lipid-based nanocarriers act as a major and most projecting approach overcoming the limitations which affect several physiochemical properties of drug such as the solubility, partition coefficient and bioavailability or absorption. This also fulfills a variety of product requirements and helps to overcome several limitations as decided by symptoms of the disease, various routes of administration of drug, price concern, increasing strength of product, noxious or harmful effect of drug, and dose efficacy. The lipidic nanosystem formulates aqueous drug in lipid base and is also a commercially feasible approach for the formulation of different dosage forms meant for topical or transdermal, oral, ocular, pulmonary, and parenteral delivery. This review provides a brief on lipid-based drug delivery nanocarrier and the mechanisms by which lipids and lipidic excipients improve the oral absorption of drugs with poor aqueous solubility and also provide a viewpoint on the promising applications of lipidic nanoparticulate systems.

Development of Rectodispersible Tablets and Granulate Capsules for the Treatment of Serious Neonatal Sepsis in Developing Countries

Current pediatric antibiotic therapies often use oral and parenteral routes of administration. Neither are suitable for treating very sick neonates who cannot take oral medication and may be several hours away from hospital in developing countries. Here, we report on the development of rectal forms of ceftriaxone, a third-generation cephalosporin. Rectodispersible tablets and capsules were developed and successfully passed 6-month accelerated stability tests. Rabbit bioavailability showed plasma concentrations above the minimal inhibitory concentrations for 3 formulations of rectodispersible tablets and 2 formulations of hard capsules. Clinical batches are currently being prepared for human evaluation with the prospect of offering therapeutic alternatives for treating critically ill neonates. This proof of concept for efficient rectal delivery of antibiotics could help the development of other rectal antibiotic treatments and increase options for noninvasive drug development for pediatric patients.

Lipid-Based Drug Delivery Systems

The principle objective of formulation of lipid-based drugs is to enhance their bioavailability. The use of lipids in drug delivery is no more a new trend now but is still the promising concept. Lipid-based drug delivery systems (LBDDS) are one of the emerging technologies designed to address challenges like the solubility and bioavailability of poorly water-soluble drugs. Lipid-based formulations can be tailored to meet a wide range of product requirements dictated by disease indication, route of administration, cost consideration, product stability, toxicity, and efficacy. These formulations are also a commercially viable strategy to formulate pharmaceuticals, for topical, oral, pulmonary, or parenteral delivery. In addition, lipid-based formulations have been shown to reduce the toxicity of various drugs by changing the biodistribution of the drug away from sensitive organs. However, the number of applications for lipid-based formulations has expanded as the nature and type of active drugs under investigation have become more varied. This paper mainly focuses on novel lipid-based formulations, namely, emulsions, vesicular systems, and lipid particulate systems and their subcategories as well as on their prominent applications in pharmaceutical drug delivery.

Anemia in chronic kidney disease: new advances

Anemia resulting from iron and erythropoietin deficiencies is a common complication of advanced chronic kidney disease (CKD). This article covers major advances in our understanding of anemia in patients with CKD, including newly discovered regulatory molecules, such as hepcidin, to innovative intravenous iron therapies. The use of erythropoiesis-stimulating agents (ESA) in the treatment of anemia has undergone seismic shift in the past 3 years as a result of adverse outcomes associated with targeting higher hemoglobin levels with these agents. Potential mechanisms for adverse outcomes, such as higher mortality, are discussed. Despite the disappointing experience with ESAs, there is a tremendous interest in other novel agents to treat anemia in CKD. Lastly, while awaiting updated guidelines, the authors outline their recommendations on how to best manage patients who are anemic and have CKD.

Engineering strategies to enhance nanoparticle-mediated oral delivery

Oral delivery is the most preferred route of drug administration due to convenience, patient compliance and cost-effectiveness. Despite these advantages it remains difficult to achieve satisfactory bioavailability levels via oral administration due to the harsh environment of the gastrointestinal (GI) tract, particularly for biomacromolecules. One promising method to increase the bioavailability of macromolecular drugs such as proteins and nucleic acids is to encapsulate them in nanoparticles before oral administration. This review describes innovative strategies for increasing the efficacy of nanoparticle-mediated delivery to the GI tract. Approaches to optimize nanoparticle formulation by exploiting mucoadhesion, environmental responsiveness and external delivery control mechanisms are discussed. The application of recent advances in nanoparticle synthesis using supercritical fluids, microfluidics and imprint lithography to oral delivery are also presented, as well as possible strategies for incorporating nanoparticles into micro- and macroscale oral delivery devices.

Approaches for the development of solid and semi-solid lipid-based formulations

Interest in Lipid Based Drug Delivery (LBDD) has developed over the past decade fuelled by a better understanding of the multiple roles lipids may play in enhancing oral bioavailability. Moreover, the emergence of novel excipients with acceptable regulatory and safety profiles coupled with advances in formulation technologies have greatly improved the potential for successful lipid based formulations. With the growing interest in this field, there is an increasing need for guidelines in excipient selection and characterization; material handling, formulation design, and processing techniques to obtain effective and patient-compliant dosage forms. The aim of this review is to present the recent approaches in selecting the most appropriate lipid system(s); methods for characterization of their behavior in vitro and in vivo; and the current formulation and processing techniques to obtain various solid dosage forms.

The influence of cosurfactants and oils on the formation of pharmaceutical microemulsions based on PEG-8 caprylic/capric glycerides

In the present study the effect of type and concentration of a cosurfactant and oil on the ability of nonionic surfactant PEG-8 caprylic/capric glycerides (Labrasol) to solubilize both oil and water phases was evaluated. Seven different cosurfactants (polyglyceryl-6 dioleate (Plurol Oleique) (PO), polyglyceryl-6 isostearate (Plurol Isostearique (PI), polyglyceryl-4 isostearate (Isolan GI 34) (IGI34), octoxynol-12 (and) polysorbate 20 (Solubilisant gamma) 2421) (SG2421), octoxynol-12 (and) polysorbate 20 (and) PEG-40 hydrogenated castor oil (Solubilisant gamma 2429) (SG2429), PEG-40 hydrogenated castor oil (Cremophor) RH 40) (CRH40) and diethyleneglycol monoethyl ether (Transcutol) and six oils (isopropyl myristate, ethyl oleate, decyl oleate, medium chain triglycerides, mineral oil and olive oil) were used in phase behaviour studies of a quaternary system Labrasol/cosurfactant/oil/water. The amount of surfactant required to completely homogenize equal masses of oil and water to form a single phase microemulsion (termed as balanced microemulsion) (S min, %w/w), the minimal concentration of the surfactant/cosurfactant blend required to produce a balanced microemulsion (SCoS min, %w/w) as well as the maximum concentration of water solubilized in investigated surfactant/oil and surfactant/cosurfactant/oil mixtures (W(max), %w/w) were determined. The obtained results indicated that Labrasol showed a good efficiency in the presence of lower molecular volume fatty acid esters with a preferred chemical structure such as isopropyl myristate (S min 56.14% (w/w); W(max) 12.28% (w/w)). Oils with high molecular volume (olive oil and mineral oil) do not result in microemulsion formation. Transcutol decreased the capacity of Labrasol for solubilization of oil and water phases. The tendency of Labrasol to solubilize both, water and oil phases, was favoured by polyglycerol-6 ester type of cosurfactants (PO and PI) while the influence of the polyglycerol-4 ester (IGI34) as well as of polyoxyethylene type of cosurfactants (CRH40, SG2421 and SG2429) on the surfactant efficiency, was not significant. Furthermore, the results revealed the significant influence of the surfactant/cosurfactant mass ratio (K(m)) on synergistic effect between polyglyceryl-6 esters and Labrasol in the formation of microemulsions using isopropyl myristate as oil phase. Optimized microemulsion systems were stabilized with Labrasol/polyglyceryl-6 esters blend at K(m) 5:5 (SCoS min, 27.5% (w/w) and W(max), 71.43% (w/w) for PI; SCoS min, 29.18% (w/w) and W(max), 65.00% (w/w) for PO) and the electrical conductivity measurement results for optimized balanced microemulsions showed that their structures were highly conductive indicating a bicontinuous microstructure.

Modulation of Ganciclovir Intestinal Absorption in Presence of Absorption Enhancers

The purpose of this investigation was to study the influences of absorption enhancers in increasing oral bioavailability of Ganciclovir (GAN) by assessing the transepithelial permeation across cell monolayers in vitro and bioavailability in rats in vivo. The permeation of GAN across Caco-2 and MDCK cell monolayers in the absence/presence of dimethyl-beta-cyclodextrin (DMbetaCD), chitosan hydrochloride (CH), sodium lauryl sulphate (SLS), and their combinations was studied for a 2-h period. GAN was administered to rats in absence/presence of absorption enhancers and drug contents in plasma were estimated. We found that the apparent permeability coefficient (Papp) of GAN in absence of absorption enhancers (control) were 0.261 +/- 0.072 x 10(-6) and 0.486 +/- 0.063 x 10(-6) cm/s in Caco-2 and MDCK cell monolayers, respectively, whereas in the presence of DMbetaCD, CH, SLS, and their combinations, Papp of GAN increased by 5- to 25-fold and 7- to 33-fold as compared to control in Caco-2 and MDCK cell monolayers, respectively. However, in rats, the maximum enhancement in bioavailability of GAN during coadministration of these absorption enhancers was only fivefold compared to GAN control. To conclude, the absorption enhancers-DMbetaCD, CH, SLS, and their combinations demonstrated significant improvement in transepithelial permeation and bioavailability of GAN.

Pharmacokinetic and pharmacodynamic studies following percutaneous absorption of erythropoietin micropiles to rats

To ascertain the pharmacological activity of erythropoietin (EPO) administered by self-dissolving micropiles (SDMP), four kinds of EPO SDMPs were prepared and were administered to rats in 4 consecutive days at 200, 500, 1000 and 2300 IU/kg. After the start of the experiment, blood samples were obtained once a day for 10 days and percent circulating reticulocytes were counted using Miller technique. At the lower doses, 200 and 500 IU/kg, pharmacological activity of EPO was not obtained. By increasing EPO dose to 1000 IU/kg, circulating reticulocytes significantly increased at days 4, 5, 6 and 7 after the start of the experiment and the average value for the change in reticulocyte levels during day 1 and day 5 was 170.9%. With the highest dose, 2300 IU/kg, higher circulating reticulocytes levels started to increase at the 4th day after the start of the experiment and maintained from day 5 to day 10. The average of the changes in reticulocyte from day 5 to day 10 was 251%. Dose-dependent circulating reticulocytes increase was observed at the higher dose range, 1000 and 2300 IU/kg. To study the linearity on the serum EPO level vs. time curves, pharmacokinetic experiment was performed with rats. After the administration of EPO SDMPs to rats, 200, 500, 1000 and 2300 IU/kg, serum EPO levels gradually increased and reached to the maximum level, C(max), at 18 h after administration. The C(max)s were 100.4+/-11.7 mIU/ml (200 IU/kg), 346.6+/-11.8 mIU/ml (500 IU/kg), 391.6+/-17.6 mIU/ml (1000 IU/kg), and 1094.9+/-114.8 mIU/ml (2300 IU/kg), respectively. AUCs were 1407+/-231, 3843+/-402, 5363+/-482 and 15,566+/-1894 mIU h/ml. Linear relation was obtained between serum EPO level and EPO dose administered as SDMP. With histological study, any adverse effect was not found out on the skin where SDMPs were administered for consecutive 4 days. These results suggest the usefulness of SDMP as a new percutaneous delivery system of EPO.