ABSTRACT
Nimesulide (NS)-loaded nanoparticles (NPNS) were prepared from polylactide-co-glycolide (PLGA) and eventually coated with chitosan (NPNSCS). Nanoparticles (NP) were spherical with sizes 379 ± 59 nm for NPNS and 393 ± 66 nm for NPNSCS and zeta potentials of -15 ± 3 mV for NPNS to 10 ± 4 mV for NPNSCS, suggesting an efficient coating. Drug encapsulation rate was high (88 ± 5% and 83 ± 7% of added drug) for NPNS and NPNSCS, respectively. After NP washing and re-suspension, 98 ± 2% and 99 ± 1% of the drug initially entrapped remained associated to NP. NS was dispersed in amorphous state within the polymeric matrix. Two-fold dilution of NP with pH 7.4 PBS provoked no drug release. However, 30-40% NS was released after a 1/10 dilution. NPNSCS and NPNS diluted 1/100 reduced the encapsulated drug to around 30% and 70%, respectively. In contrast, 100% NS was released from NP under sink conditions in less than 2h. The permeability of free-NS (1-1.5 × 10(-5)cm/s) was compared with NPNS (NPNS = 6.4-8.1 × 10(-6)cm/s and NPNSCS = 5.5-7.0 × 10(-6)cm/s) using the PAMPA assay. The cytotoxicity of free-NS and NS in NP on model prostate cancer cells PC-3 and DU-145 showed the highest cytotoxic effect with NPNSCS on PC-3 cells (IC50 = 89 µM).
Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/administration & dosage , Nanoparticles/chemistry , Sulfonamides/administration & dosage , Calorimetry, Differential Scanning , Cell Line, Tumor , Cell Survival , Chitosan/chemistry , Drug Carriers/chemistry , Drug Liberation , Humans , Lactic Acid/chemistry , Male , Particle Size , Polyglycolic Acid/chemistry , Polylactic Acid-Polyglycolic Acid Copolymer , Prostatic Neoplasms/drug therapy , Spectroscopy, Fourier Transform InfraredABSTRACT
Cannabinoids present an interesting therapeutic potential as antiemetics, appetite stimulants in debilitating diseases (cancer, AIDS and multiple sclerosis), analgesics, and in the treatment of multiple sclerosis and cancer, among other conditions. However, despite their high clinical potential, only few dosage forms are available to date. In this paper, the development of Δ(9)-tetrahydrocannabinol (THC) biodegradable microspheres as an alternative delivery system for cannabinoid parenteral administration is proposed. Tetrahydrocannabinol was encapsulated into biodegradable microspheres by the oil-in-water (o/w) emulsion solvent evaporation method. Several formulations were prepared using different drug:polymer ratios. The influence of antioxidant (α-tocopherol acetate) concentration on the release of THC from the microparticles was studied. Elevated process yield and entrapment efficiencies were achieved. The in vitro drug release studies showed that the encapsulated drug was released over a two week period. As THC has shown therapeutic potential as anticancer drug, the efficacy of the microspheres was tested on different cancer cell lines. Interestingly, the microspheres were able to inhibit cancer cell proliferation during the nine-day study period. All the above results suggest that the use of biodegradable microspheres would be a suitable alternative delivery system for THC administration.
Subject(s)
Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Antioxidants/chemistry , Dronabinol/chemistry , Dronabinol/pharmacology , Polymers/chemistry , Animals , Antioxidants/pharmacology , Caco-2 Cells , Cell Line, Tumor , Cell Proliferation/drug effects , Drug Delivery Systems/methods , Emulsions/chemistry , Emulsions/pharmacology , Humans , Microspheres , Particle Size , Rats , Solvents/chemistryABSTRACT
Cannabinoids, the active components of marijuana and their derivatives, are currently investigated due to their potential therapeutic application for the management of many different diseases, including cancer. Specifically, Δ(9)-Tetrahydrocannabinol (THC) and Cannabidiol (CBD) - the two major ingredients of marijuana - have been shown to inhibit tumor growth in a number of animal models of cancer, including glioma. Although there are several pharmaceutical preparations that permit the oral administration of THC or its analogue nabilone or the oromucosal delivery of a THC- and CBD-enriched cannabis extract, the systemic administration of cannabinoids has several limitations in part derived from the high lipophilicity exhibited by these compounds. In this work we analyzed CBD- and THC-loaded poly-ε-caprolactone microparticles as an alternative delivery system for long-term cannabinoid administration in a murine xenograft model of glioma. In vitro characterization of THC- and CBD-loaded microparticles showed that this method of microencapsulation facilitates a sustained release of the two cannabinoids for several days. Local administration of THC-, CBD- or a mixture (1:1 w:w) of THC- and CBD-loaded microparticles every 5 days to mice bearing glioma xenografts reduced tumour growth with the same efficacy than a daily local administration of the equivalent amount of those cannabinoids in solution. Moreover, treatment with cannabinoid-loaded microparticles enhanced apoptosis and decreased cell proliferation and angiogenesis in these tumours. Our findings support that THC- and CBD-loaded microparticles could be used as an alternative method of cannabinoid delivery in anticancer therapies.
