Niosomal Formulation Studies to Overcome Reduced Bioavailability of Antifungal Agent Griseofulvin

Introduction Griseofulvin, an antifungal drug used to treat dermatophyte infections, exhibits poor aqueous solubility and low bioavailability (25–70%), classified as a Biopharmaceutics Classification System (BCS) Class II drug. This limits its therapeutic efficacy and necessitates high doses, increasing the risk of side effects such as gastrointestinal distress and hepatotoxicity. Niosomes, non-ionic surfactant-based vesicles, offer a promising drug delivery system due to their ability to encapsulate hydrophobic drugs, enhance solubility, and improve bioavailability through controlled release and enhanced membrane penetration. This research proposes to develop and evaluate niosomal formulations to overcome the reduced bioavailability of Griseofulvin, aiming to improve its clinical efficacy and patient compliance. 1. Research Objectives The primary objective is to design and optimize niosomal formulations to enhance the bioavailability of Griseofulvin. Specific objectives include: 1. To formulate and characterize Griseofulvin-loaded niosomes using various non-ionic surfactants and cholesterol ratios. 2. To evaluate the impact of niosomal encapsulation on Griseofulvin’s solubility, dissolution rate, and stability. 3. To investigate the in vitro release kinetics and cellular uptake of niosomal Griseofulvin. 4. To assess the pharmacokinetic profile and bioavailability of optimized niosomal formulations in vivo compared to conventional Griseofulvin formulations. 5. To evaluate the safety and scalability of the niosomal formulations for potential clinical application. 2. Background and Significance Griseofulvin’s poor solubility and variable absorption are major challenges in its clinical use. Previous approaches, such as micronization and cyclodextrin complexation, have shown limited success due to inconsistent bioavailability and high costs. Niosomes, structurally similar to liposomes but more stable and cost-effective, can encapsulate both hydrophilic and hydrophobic drugs, offering advantages like enhanced solubility, prolonged release, and improved intestinal absorption via lymphatic uptake or paracellular pathways. Recent studies have demonstrated niosomes’ potential in improving the bioavailability of poorly soluble drugs like itraconazole and curcumin. This research aims to leverage niosomal technology to address Griseofulvin’s limitations, potentially reducing dosing frequency and side effects while enhancing therapeutic outcomes. 3. Research Methodology 3.1. Formulation Development Niosome Preparation: 1. Formulate Griseofulvin-loaded niosomes using non-ionic surfactants (e.g., Span 60, Tween 80) and cholesterol via thin-film hydration, ether injection, or reverse-phase evaporation techniques. 2. Optimize surfactant-to-cholesterol ratios and drug loading using Design of Experiments (DoE) to achieve desired vesicle size and entrapment efficiency. Variables: 1. Surfactant type and concentration. 2. Cholesterol content. 3. Hydration medium (pH, volume). 4. Sonication time and amplitude for size reduction. 3.2. Physicochemical Characterization 1. Entrapment Efficiency: Quantify encapsulated Griseofulvin using UV-Vis spectroscopy or HPLC after separating free drug via ultracentrifugation. 2. Vesicle Size and Zeta Potential: Measure using dynamic light scattering (DLS) and zeta potential analyzer. 3. Morphology: Visualize niosome structure using transmission electron microscopy (TEM) and atomic force microscopy (AFM) 4. Drug-Surfactant Interactions: Analyze using Fourier-transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). 5. Stability Studies: Assess physical and chemical stability under accelerated conditions (40°C/75% RH) for 6 months, monitoring vesicle size, drug leakage, and aggregation. 3.3. In Vitro Studies 1. Solubility and Dissolution Testing: Evaluate solubility in simulated gastric (pH 1.2) and intestinal (pH 6.8) fluids. Conduct dissolution studies using USP Type II apparatus to compare release profiles with conventional Griseofulvin. 2. Release Kinetics: Study in vitro drug release in phosphate-buffered saline (pH 7.4) using dialysis membrane, fitting data to kinetic models (e.g., zero-order, Higuchi, Korsmeyer-Peppas). 3. Cellular Uptake: Assess niosome uptake in Caco-2 cell lines using fluorescence-labeled niosomes, quantifying internalization via flow cytometry or confocal microscopy. 3.4. In Vivo Studies  Animal Model: Use albino mice (n=6 per group) to evaluate pharmacokinetic parameters (Cmax, Tmax, AUC) following oral administration of optimized niosomal formulations compared to marketed Griseofulvin suspension.  Bioavailability Assessment: Quantify plasma concentrations using HPLC-MS/MS. Calculate relative bioavailability and statistical significance using ANOVA.  Safety Evaluation: Monitor for toxicity through histopathological analysis of liver, kidney, and intestinal tissues. Assess hematological and biochemical parameters. 3.5. Data Analysis  Optimize formulation parameters using response surface methodology (RSM) within DoE.  Compare in vitro and in vivo performance using statistical tests (e.g., t-tests, ANOVA).  Model pharmacokinetic data using non-compartmental analysis (WinNonlin software). 4. Expected Outcomes  Development of stable niosomal formulations with high Griseofulvin entrapment efficiency (>70%) and vesicle size <200 nm.  Significant enhancement in solubility and dissolution rate compared to free Griseofulvin.  A 2–3-fold increase in bioavailability, evidenced by higher AUC and Cmax in vivo.  Controlled release profile suitable for once-daily dosing.  Safe and scalable formulations with potential for clinical translation. 5. Timeline Phase Duration Activities Literature Review 2 months Background research, hypothesis formulation Formulation Development 6 months Niosome preparation and optimization In Vitro Studies 4 months Characterization, dissolution, cellular uptake In Vivo Studies 6 months Pharmacokinetic and safety studies Data Analysis & Reporting 4 months Statistical analysis, manuscript preparation Total Duration: 22 months   6. Budget Item Estimated Cost (USD) Materials (API, surfactants, cholesterol) 12,000 Equipment (HPLC, DLS, TEM) 15,000 Animal Studies 20,000 Personnel (2 researchers) 50,000 Miscellaneous (travel, publication) 5,000 Total 102,000 7. Ethical Considerations  Animal studies will adhere to Institutional Animal Care and Use Committee (IACUC) guidelines, ensuring minimal animal use.  In vitro models (e.g., Caco-2 cells) will be prioritized to reduce animal testing where possible.  All experiments will follow Good Laboratory Practices (GLP) to ensure reproducibility and ethical conduct. 8. Conclusion This research aims to address the critical issue of Griseofulvin’s low bioavailability by developing niosomal formulations that enhance solubility, dissolution, and absorption. The proposed study leverages the unique advantages of niosomes to improve therapeutic outcomes for fungal infections, potentially reducing dosing requirements and side effects. Successful outcomes could provide a scalable, cost-effective solution for Griseofulvin delivery and serve as a model for other poorly soluble drugs. 9. References 1. Kazi, K. M., et al. (2010). Niosomes as a novel drug delivery system: A review. International Journal of Pharmaceutical Sciences Review and Research, 3(2), 167–175. 2. Patel, D. M., et al. (2015). Niosomal drug delivery system: A novel approach for bioavailability enhancement. Journal of Drug Delivery and Therapeutics, 5(4), 1–8. 3. Savjani, K. T., et al. (2012). Drug solubility: Importance and enhancement techniques. ISRN Pharmaceutics, 2012, 195727.