Encapsulation of Cancer Therapeutic Agent Dacarbazine Using Nanostructured Lipid Carrier
April 26th, 2016
The most commonly used method for nanostructured lipid carrier (NLC) synthesis involves oil-in-water emulsion, homogenization and solidification. This was modified here by applying high shear dispersion after solidification to achieve a NLC with desirable size, improved drug encapsulation and drug loading efficiency as a potential carrier for dacarbazine delivery.
The overall goal of this procedure is to prepare a nanostructured lipid carrier for encapsulating the cancer therapeutic agent dacarbazine. This procedure is simple and well-optimized. Allowing for the preparation of nanostructured lipid carrier with a well-controlled capacity.
The main advantages of the new formulation of dacarbazine include increased drug dispersity in aqueous solution, prolonged historic stability and improved drug-release control. This improvement can potentially lead to prolonged half-life in vivo as well. Begin by adding 6.25ml each of acetone and ethanol to a flask.
To the solvents, add glyceryl palmitosterate isopropyl myristate, D-a-tocopheryl polyethylene glycol succinate and soybean lecithin. Dissolve the mixture at 70 degrees Celsius in a water bath. Into an additional flask, add 12.5ml of water.
Create a solution of 1%poloxamer 188 by dissolving 125mg into the water. Heat the flask to 70 degrees Celsius to dissolve the chemical fully. While stirring the organic solution at 400 rpm dropwise add the 1%poloxamer 188 solution to form an emulsion.
Stir the emulsion for an additional four hours to evaporate the organic solvent. After four hours, place the emulsion in a fridge at four degrees Celsius for two hours to solidify. To obtain nanostructured lipid carriers or NLCs, use a homogenizer to subject the solidified emulsions to high shear dispersion.
Mix the solution at 15000 rpm for 30 minutes to disperse the emulsion. Sample the solution in 10 minute increments. Take 14 microliters of emulsion in a dynamic light scattering or DLS cuvette.
And dilute to 1ml with deuterated water for measurement. Read the cuvette sample in the instrument. Examine the samples to assess which samples have the smallest size and smallest polydispersion index.
Therefore, to determine the optimal mix speed and mix time for NLC creation. Observe samples for morphology and ultrastructure of the NLC. Apply the same dilution of samples to the carbon fiber-coated copper grid of a transmission electron microscope instrument.
Allow the sample to air-dry and then run the sample per the manufacturer's instructions. Now that conditions have been optimized, prepare a solution as performed for the initial emulsions. After combining the glyceryl, isopropyl, polyethylene glycol succinate and soybean lecithin reagents add 70mg of dacarbazine and then heat the solution to 70 degrees Celsius.
Prepare 12.5ml of an aqueous 1%poloxamer 188 solution. Heat the flask to 70 degrees Celsius. After dissolving the poloxamer 188 add the solution dropwise to the organic solution, stirring at 400 rpm to form an emulsion.
Stir the emulsion for an additional four hours to evaporate the organic solvent. As before, place the emulsion in a cold room at four degrees Celsius for two hours to solidify. Use the optimized high dispersion speed of 15000 rpm for 30 minutes to homogenize the emulsion.
The preparations of the NLC and the dacarpazine-loaded NLC with different parameters were characterized for particle size and polydispersion index. The particle size and polydispersion index of the NLCs were surfactant concentration, high shear dispersion speed and duration dependent. As judged by particle size and polydispersion index, the best results were achieved with 1%of surfactant and the shear dispersion speed of 15000 rpm for 30 minutes.
Which were selected as the optimal parameters for NLC preparation in this study. When the optimal parameters were used for dacarbazine-loaded NLC preparation, the smallest size achieved was 155 nanometers for NLC and 190 nanometers for dacarbazine-loaded NLC. Both with a polydispersion index of 0.2, indicating good uniformity.
The uploading and encapsulation of dacarbazine in NLC is indicated by the size and structure changes. Where dacarbazine-loaded NLC show larger size and altered internal structures compared with NLC. Once mastered, this technique can be done in eight hours if it is performed perfectly.
While attempting this procedure, it's very important to remember that the lines of the evaporation the solidification is very critical. As too long or too short will have negative effect on the generation of nanostructured lipid carriers. Following this procedure, the reduced nanostructured lipid carrier are stable for six months at four degrees Centigrade.
Allowing characterizations such as pharmacology and toxicology to be performed. This technique paved the way for those in constant research to explore nanostructured carrier-based formulation of dacarbazine for a variety of cancer treatments. To date, the dacarbazine is the most active agent in treating cutaneous and metastatic melanoma.
After watching this video you should have a good understanding of how to prepare nanostructured lipid carrier and use nanostructured lipid carrier to encapsulate dacarbazine. While working with hazardous materials such as dacarbazine, personal protection equipment, including lab coat, protective gloves, and eye protection should always be used. Access to is also needed for working with the hazardous solvent.
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Overview
This study presents a modified method for synthesizing nanostructured lipid carriers (NLCs) for the delivery of the cancer drug dacarbazine. The new approach enhances drug encapsulation and loading efficiency, potentially improving therapeutic outcomes.
Key Study Components
Area of Science
- Nanotechnology
- Pharmaceutical Sciences
- Cancer Therapy
Background
- Nanostructured lipid carriers are effective for drug delivery.
- Dacarbazine is a chemotherapeutic agent used in cancer treatment.
- Improving drug delivery systems can enhance therapeutic efficacy.
- Traditional methods may limit drug encapsulation and stability.
Purpose of Study
- To develop a more efficient NLC for dacarbazine delivery.
- To achieve improved drug dispersity and stability in solution.
- To enhance drug-release control for better therapeutic outcomes.
Methods Used
- Oil-in-water emulsion technique for NLC synthesis.
- High shear dispersion applied post-solidification.
- Characterization of NLC size and drug loading efficiency.
- Evaluation of drug dispersity and stability in aqueous solutions.
Main Results
- Modified synthesis method resulted in desirable NLC size.
- Improved drug encapsulation and loading efficiency observed.
- Enhanced drug dispersity and prolonged stability in solution.
- Potential for improved drug-release control and half-life in vivo.
Conclusions
- The new NLC formulation shows promise for cancer therapy.
- Method modifications can lead to significant improvements in drug delivery.
- Further studies are needed to assess in vivo efficacy.
Frequently Asked Questions
Executive Industry Relevance
Nanostructured lipid carriers (NLCs) address the poor aqueous dispersity of dacarbazine, a key limitation in its intravenous formulation, by enhancing drug solubility and stability. This delivery system enables prolonged half-life and improved release control, supporting preclinical evaluation of chemotherapeutic agents. The method provides a scalable platform for reformulating hydrophobic oncology drugs to improve therapeutic index and reduce formulation-related attrition.
Strategic Applications in Biopharma R&D
Early Discovery & Target Validation
- Scientific Value: Enables formulation of poorly water-soluble anticancer agents like dacarbazine for in vitro and in vivo pharmacological screening.
- Operational Value: Provides a reproducible nanoparticle system to isolate drug-specific effects from formulation artifacts in target validation assays.
Screening & Assay Development
- Scientific Value: Generates uniform NLCs (190 ± 10 nm, PDI 0.2 ± 0.01) suitable for high-throughput cytotoxicity and mechanism-of-action assays.
- Operational Value: Achieves high encapsulation efficiency (98%) and drug loading (14%), ensuring consistent dosing across compound libraries.
Translational & Preclinical Research
- Scientific Value: Supports pharmacokinetic and toxicology studies by improving drug dispersity and stability for six months at 4°C.
- Operational Value: Enables scale-up via high shear dispersion (15,000 rpm, 30 min) following solidification, a process compatible with GMP-adjacent pilot production.
Pipeline & Workflow Integration
This NLC formulation fits within the oncology discovery continuum from hit validation to lead optimization, where controlled drug release and solubility are critical for assessing target engagement and safety margins.
- Discovery Biology: Facilitates hypothesis testing by delivering dacarbazine in a stable, dispersible form to evaluate melanoma cell line responses.
- Screening: Produces NLCs with zeta potential of -43.5 ± 1.2 mV, ensuring colloidal stability in aqueous screening media.
- Analytics: Enables quantification of drug release and encapsulation efficiency via DLS and HPLC, supporting structure-activity relationship studies.
- Translational Research: Aligns with preclinical continuity by providing a stable nanocarrier for biodistribution and melanoma xenograft models.
- Enterprise Reuse: The HSD-based NLC platform is adaptable to other hydrophobic therapeutics, reducing redevelopment effort across oncology pipelines.
Operational & Enterprise Impact
- Scientific Value: Improves predictive confidence in anticancer screening by minimizing variability due to drug aggregation or precipitation.
- Operational Value: Uses readily available lipids (glyceryl palmitostearate, isopropyl myristate) and surfactants (poloxamer 188, lecithin) for cost-effective synthesis.
- Strategic Value: Reduces late-stage failure risk by addressing solubility-driven bioavailability issues early in development.
- Portfolio Impact: Enables risk-adjusted prioritization of dacarbazine derivatives and analogs through improved formulation feasibility.
Implementation Considerations
- Requires expertise in lipid nanoparticle formulation and high-shear homogenization techniques.
- Dependent on access to homogenizers capable of 15,000 rpm and analytical tools like DLS and TEM for characterization.
- Necessitates standardization of surfactant concentration (1%) and solidification protocols (4°C, 2 hr) across teams for batch consistency.
- Adaptation to other cancer therapeutics may require lipid matrix optimization to maintain encapsulation efficiency.
- Limited by the need for cold storage (4°C) to maintain NLC stability over six months, impacting long-term storage logistics.
