Formulation and Evaluation of Liposomal Drug Delivery System for Sulfasalazine

Aim: Aim of the current study is to prepare and characterize sulfasalazine-loaded liposomes to improve the bioavailability of the drug and to lessen the adverse effects of the drug. Background: Diseases like inflammatory bowel disease can be treated by anti-inflammatory agents like “Sulfasalazine,” It can also be used to treat ulcerative colitis and Crohn’s disease. The biological half-life of sulfasalazine is 5-10hr; as in the case of conventional therapy, there is a chance of missing the dose. Therefore, frequent administration of drugs is essential to maintain the desired steady-state level. The side effects are thrombocytopenia, megaloblastic anemia, bone marrow depression, folic acid deficiency, impairment of male fertility (Oligospermia), intestinal nephritis due to 5-ASA, diarrhoea, headache, and skin rashes. The bioavailability of sulfasalazine is 15%. This work was undertaken to enhance bioavailability and decrease the side effects. Objective: The main objective of the study is to improve the solubility of sulfasalazine by formulating a liposomal drug delivery system. The major objective is to develop a liposomal formulation with good stability and the highest entrapment efficiency. Methods: Liposomes were produced by the thin-film hydration method. Nine formulations of liposomes were prepared by varying the concentrations of soya lecithin and cholesterol and changing the drug ratio. The obtained liposomes were characterized for surface morphology, FTIR, particle size, zeta potential, drug content, entrapment efficiency, and in-vitro diffusion studies. Results: Among the nine formulations of liposomes, F3 was found to be the best formulation with an entrapment efficiency of 97.8% and a zeta potential value of -37.2mV. Liposomes followed first-order kinetics with a non-fickian diffusion pathway. Conclusions: Sulfasalazine loaded liposomes were prepared with good stability and the highest entrapment efficiency.

SapC–DOPS as a Novel Therapeutic and Diagnostic Agent for Glioblastoma Therapy and Detection: Alternative to Old Drugs and Agents

Glioblastoma multiforme (GBM), the most common type of brain cancer, is extremely aggressive and has a dreadful prognosis. GBM comprises 60% of adult brain tumors and the 5 year survival rate of GBM patients is only 4.3%. Standard-of-care treatment includes maximal surgical removal of the tumor in combination with radiation and temozolomide (TMZ) chemotherapy. TMZ is the “gold-standard” chemotherapy for patients suffering from GBM. However, the median survival is only about 12 to 18 months with this protocol. Consequently, there is a critical need to develop new therapeutic options for treatment of GBM. Nanomaterials have unique properties as multifunctional platforms for brain tumor therapy and diagnosis. As one of the nanomaterials, lipid-based nanocarriers are capable of delivering chemotherapeutics and imaging agents to tumor sites by enhancing the permeability of the compound through the blood–brain barrier, which makes them ideal for GBM therapy and imaging. Nanocarriers also can be used for delivery of radiosensitizers to the tumor to enhance the efficacy of the radiation therapy. Previously, high-atomic-number element-containing particles such as gold nanoparticles and liposomes have been used as radiosensitizers. SapC–DOPS, a protein-based liposomal drug comprising the lipid, dioleoylphosphatidylserine (DOPS), and the protein, saposin C (SapC), has been shown to be effective for treatment of a variety of cancers in small animals, including GBM. SapC–DOPS also has the unique ability to be used as a carrier for delivery of radiotheranostic agents for nuclear imaging and radiotherapeutic purposes. These unique properties make tumor-targeting proteo-liposome nanocarriers novel therapeutic and diagnostic alternatives to traditional chemotherapeutics and imaging agents. This article reviews various treatment modalities including nanolipid-based delivery and therapeutic systems used in preclinical and clinical trial settings for GBM treatment and detection.

Application of Box–Behnken Design and Desirability Function in the Development and Optimization of Stealth Liposomes of Microtubule Inhibitor

Aims: The aim of the present study was to develop and optimize a Stealth Liposomal Drug Delivery System of microtubule inhibitor using Box–Behnken Design and Desirability function. Study Design: Development and Optimization of Stealth Liposomes. Place and Duration of Study: The study was carried out in the Department of Pharmacy, Annamalai University, between September 2020 and May 2021. Methodology: Stealth Liposomes were prepared by the thin-film hydration method (TFH). The formulation was optimized using Box – Behnken design to study the effect of independent variables, Amount of Egg Phosphatidylcholine (X1), Amount of Cholesterol (X2), and Amount of DSPE-PEG 2000(X3) on dependent variables Entrapment Efficiency (Y1) and In-vitro drug release (Y2). Results: Entrapment efficiency of the Stealth Liposomes ranges from 56.35 to 84.25%and in-vitro release ranges from 62.38 to 94.26%. The optimized formulation was found using the desirability function to get maximum entrapment with maximum drug release. The optimized formulation showed entrapment efficiency of 80.46% and in-vitro release of 90.11%. Conclusion: Stealth Liposomal Drug Delivery System for microtubule inhibitor was successfully developed and optimized using desirability function in Design Expert software by a three-factor, three level Box – Behnken design.

Understanding Drug Delivery to the Brain Using Liposome-Based Strategies: Studies that Provide Mechanistic Insights Are Essential

Brain drug delivery may be restricted by the blood-brain barrier (BBB), and enhancement by liposome-based drug delivery strategies has been investigated. As access to the human brain is limited, many studies have been performed in experimental animals. Whereas providing interesting data, such studies have room for improvement to provide mechanistic insight into the rate and extent of specifically BBB transport and intrabrain distribution processes that all together govern CNS target delivery of the free drug. This review shortly summarizes BBB transport and current liposome-based strategies to overcome BBB transport restrictions, with the emphasis on how to determine the individual mechanisms that all together determine the time course of free drug brain concentrations, following their administration as such, and in liposomes. Animal studies using microdialysis providing time course information on unbound drug in plasma and brain are highlighted, as these provide the mechanistic information needed to understand BBB drug transport of the drug, and the impact of a liposomal formulations of that drug on BBB transport. Overall, these studies show that brain distribution of a drug administered as liposomal formulation depends on both drug properties and liposomal formulation characteristics. In general, evidence suggests that active transporters at the BBB, either being influx or efflux transporters, are circumvented by liposomes. It is concluded that liposomal formulations may provide interesting changes in BBB transport. More mechanistic studies are needed to understand relevant mechanisms in liposomal drug delivery to the brain, providing an improved basis for its prediction in human using animal data.

Challenges of Current Anticancer Treatment Approaches with Focus on Liposomal Drug Delivery Systems

According to a 2020 World Health Organization report (Globocan 2020), cancer was a leading cause of death worldwide, accounting for nearly 10 million deaths in 2020. The aim of anticancer therapy is to specifically inhibit the growth of cancer cells while sparing normal dividing cells. Conventional chemotherapy, radiotherapy and surgical treatments have often been plagued by the frequency and severity of side effects as well as severe patient discomfort. Cancer targeting by drug delivery systems, owing to their selective targeting, efficacy, biocompatibility and high drug payload, provides an attractive alternative treatment; however, there are technical, therapeutic, manufacturing and clinical barriers that limit their use. This article provides a brief review of the challenges of conventional anticancer therapies and anticancer drug targeting with a special focus on liposomal drug delivery systems.

Aiming for a bull’s-eye: Targeting antifungals to fungi with dectin-decorated liposomes

Globally, there are several million individuals with life-threatening invasive fungal diseases such as candidiasis, aspergillosis, cryptococcosis, Pneumocystis pneumonia (PCP), and mucormycosis. The mortality rate for these diseases generally exceeds 40%. Annual medical costs to treat these invasive fungal diseases in the United States exceed several billion dollars. In addition to AIDS patients, the risks of invasive mycoses are increasingly found in immune-impaired individuals or in immunosuppressed patients following stem cell or organ transplant or implantation of medical devices. Current antifungal drug therapies are not meeting the challenge, because (1) at safe doses, they do not provide sufficient fungal clearance to prevent reemergence of infection; (2) most become toxic with extended use; (3) drug-resistant fungal isolates are emerging; and (4) only one new class of antifungal drugs has been approved for clinical use in the last 2 decades. DectiSomes represent a novel design of drug delivery to drastically increase drug efficacy. Antifungals packaged in liposomes are targeted specifically to where the pathogen is, through binding to the fungal cell walls or exopolysaccharide matrices using the carbohydrate recognition domains of pathogen receptors. Relative to untargeted liposomal drug, DectiSomes show order of magnitude increases in the binding to and killing of Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus in vitro and similarly improved efficacy in mouse models of pulmonary aspergillosis. DectiSomes have the potential to usher in a new antifungal drug treatment paradigm.

Liposomal drug delivery to manage nontuberculous mycobacterial pulmonary disease and other chronic lung infections

Nontuberculous mycobacterial (NTM) pulmonary disease is a chronic respiratory infection associated with declining lung function, radiological deterioration and significantly increased morbidity and mortality. Patients often have underlying lung conditions, particularly bronchiectasis and COPD. NTM pulmonary disease is difficult to treat because mycobacteria can evade host defences and antimicrobial therapy through extracellular persistence in biofilms and sequestration into macrophages. Management of NTM pulmonary disease remains challenging and outcomes are often poor, partly due to limited penetration of antibiotics into intracellular spaces and biofilms. Efficient drug delivery to the site of infection is therefore a key objective of treatment, but there is high variability in lung penetration by antibiotics. Inhalation is the most direct route of delivery and has demonstrated increased efficacy of antibiotics like amikacin compared with systemic administration. Liposomes are small, artificial, enclosed spherical vesicles, in which drug molecules can be encapsulated to provide controlled release, with potentially improved pharmacokinetics and reduced toxicity. They are especially useful for drugs where penetration of cell membranes is essential. Inhaled delivery of liposomal drug solutions can therefore facilitate direct access to macrophages in the lung where the infecting NTM may reside. A range of liposomal drugs are currently being evaluated in respiratory diseases.