Improving the therapeutic efficacy of prilocaine by PLGA microparticles: Preparation, characterization and in vivo evaluation.

A delivery system based on poly(lactic-co-glycolic acid) polymer (PLGA) microparticles has been developed for parenteral administration of the local anesthetic prilocaine in its free base form. Both drug-free and drug-loaded microparticles, prepared by a double-emulsion-evaporation method, were characterized for mean size by Laser Diffraction Analysis, while their morphology was investigated by scanning electron microscopy. The preparation technique allowed obtainment of homogeneous microparticles of about 25 µm diameter, suitable for subcutaneous administration.

Synthesis of an acridine orange sulfonamide derivative with potent carbonic anhydrase IX inhibitory action.

Acridine orange (AO) a fluorescent cationic dye used for the management of human musculoskeletal sarcomas, due to its strong tumoricidal action and accumulation in the acidic environment typical of hypoxic tumors, was used for the preparation of a primary sulfonamide derivative. The rationale behind the drug design is the fact that hypoxic, acidic tumors overexpress carbonic anhydrase (CA, EC 4.2.

Cyclodextrin complexation highly enhances efficacy of arylsulfonylureido benzenesulfonamide carbonic anhydrase inhibitors as a topical antiglaucoma agents.

Two new sulfonamides incorporating arylsulfonylureido moieties were complexed with gamma cyclodextrin (γ-CD), hydroxypropyl-gamma cyclodextrin (HPγ-CD), hydroxypropyl-beta cyclodextrin (HPβ-CD) and hydroxyethyl-beta cyclodextrin (HEβ-CD) in order to obtain drug formulations with effective topical intraocular pressure (IOP) lowering effects, in an animal model of glaucoma. The HPγ-CD was the best solubilizing agent for the two sulfonamides and its complexes were characterized in detail and administered to rabbits with eye hypertension of 45-50 mmHg. The peak IOP lowering was observed after 1h post-administration and was of 36-37 mmHg.

Development and ex vivo evaluation of 5-aminolevulinic acid-loaded niosomal formulations for topical photodynamic therapy.

The objective of this study was the development of a niosomal formulation for improving skin permeation and penetration of 5-aminolevulinic acid (ALA) in the treatment of skin malignancies by photodynamic therapy (PDT). Different niosomal dispersions were prepared, using two different preparation methods. The effect of addition to a classic formulation, consisting in an equimolar Span 60-cholesterol mixture, of two different edge activators, dicethyl-phosphate (DCP) and sodium cholate (SC), and of the presence of ethanol on the vesicle properties and stability was evaluated.

Development of liposomal and microemulsion formulations for transdermal delivery of clonazepam: effect of randomly methylated β-cyclodextrin.

Transdermal administration of clonazepam, a poorly water-soluble benzodiazepine, is an interesting strategy for overcoming the drawbacks of its oral administration. With this aim, two nano-carrier formulations, based on ultra-deformable liposomes and microemulsions, have been developed to favour clonazepam transdermal delivery. Considering the solubilizing power of methyl-βcyclodextrin (Me-βCD) toward clonazepam and its potential positive influence on transdermal drug delivery, the effect of its addition to these formulations was investigated.

New series of sulfonamides containing amino acid moiety act as effective and selective inhibitors of tumor-associated carbonic anhydrase XII.

New benzenesulfonamides incorporating water solubilizing moieties were synthesized using N-α-acetyl-l-lysine or γ-aminobutyric acid as scaffolds followed by the conversion of their terminal amino group to the guanidine one. Their inhibition activity was assessed by determining their KIs values against the human (h) carbonic anhydrase (CA, EC 4.2.

Physico-chemical characterization in solution and in the solid state of clonazepam complexes with native and chemically-modified cyclodextrins.

Clonazepam (CLZ) is a benzodiazepine derivative, whose bioavailability, limited by its very poor water-solubility, could be improved by cyclodextrin complexation. However, the choice of the most proper cyclodextrin to use to fully exploit its potential favourable effects on the drug, is a critical step. Therefore, in the present work, the performance of some amorphous cyclodextrin (CD) derivatives in terms of complexing, solubilizing and amorphizing power towards CLZ was carefully evaluated and compared with that of natural CDs.

Development of a chitosan-derivative micellar formulation to improve celecoxib solubility and bioavailability.

Context: Celecoxib is an anti-inflammatory drug, specific inhibitor of COX-2, classified as a BCS class II compound due to its very low aqueous solubility (3 μg/mL) and good permeability.

Objective: An innovative micellar formulation of celecoxib has been developed to increase its solubility and, consequently, its oral bioavailability.

Materials And Methods: Quaternary-ammonium-palmitoyl-glycol-chitosan (GCPQ) was selected as carrier, due to its micelle-forming ability joined to its solubilizing and enhancer properties towards hydrophobic drugs.

Selection of PLA polymers for the development of injectable prilocaine controlled release microparticles: usefulness of thermal analysis.

The use of injectable local anaesthetics for the treatment of severe postoperative pain is limited by the short duration of the painkilling effect. Pre-formulation studies were carried out for the development of an injectable microparticle formulation for controlled release of prilocaine, an amino-amide type local anaesthetic suitable for intravenous, subcutaneous and intramuscular administration. To the best of our knowledge, the encapsulation of prilocaine into microparticles has not been investigated yet.

Comparative study of liposomes, transfersomes and ethosomes as carriers for improving topical delivery of celecoxib.

Topical administration of celecoxib proved to be an effective mean of preventing skin cancer development and improving anticancer drugs effectiveness in skin tumors treatment. The aim of this study was the development of an effective topical formulation of celecoxib, able to promote drug skin delivery, providing its in depth penetration through the skin layers. Three kinds of vesicular formulations have been investigated as drug carriers: liposomes containing a surfactant, or transfersomes and ethosomes, containing suitable edge activators.

Development and characterization of niosomal formulations of doxorubicin aimed at brain targeting.

Purpose: The aim of the present work was the development and characterization of a niosomal formulation functionalized with the glucose-derivative N-palmitoylglucosamine (NPG) to obtain a potential brain targeted delivery system for the anticancer agent doxorubicin.

Methods: Five different methods have been examined for vesicle preparation. Light scattering and transmission electron microscopy were used for vesicle characterization, in terms of mean size, homogeneity and Zeta potential, and selection of the best composition and preparation conditions for developing NPG-functionalized niosomes.

Development of mucoadhesive films for buccal administration of flufenamic acid: Effect of cyclodextrin complexation.

A new mucoadhesive film for topical administration in the oral cavity of flufenamic acid, a poorly soluble anti-inflammatory drug, has been developed, using complexation with hydroxypropyl-beta-cyclodextrin (HPbetaCD) to improve drug dissolution and release rate. Buccal films were prepared utilising chitosan as mucoadhesive polymer, KollicoatIR as film-forming polymer and glycerol as plasticiser. Different combinations of these components were used and the obtained films were characterised for weight, thickness, swelling, mucoadhesive and mechanical properties.

Development of a new delivery system consisting in 'drug-in cyclodextrin-in PLGA nanoparticles'.

A combined approach based on drug cyclodextrin (CD) complexation and loading into PLGA nanoparticles (NP) has been developed to improve oxaprozin therapeutic efficiency. This strategy exploits the solubilizing and stabilizing properties of CDs and the prolonged-release and targeting properties of PLGA NPs. Drug-loaded NPs, prepared by double-emulsion, were examined for dimensions, zeta-potential and entrapment efficiency.

Liposomal formulations of prilocaine: effect of complexation with hydroxypropyl-ß-cyclodextrin on drug anesthetic efficacy.

A combined strategy, based on cyclodextrin complexation and loading in liposomes, has been investigated to develop a new delivery system with improved therapeutic activity of the local anesthetic, prilocaine (PRL). In order to evaluate the actual effectiveness and advantages of this approach compared to the traditional drug-in-liposome one, four different liposomal formulations were prepared: (1) liposomes loaded with PRL base as complex with hydroxypropyl-β-cyclodextrin (HP CD) in the aqueous phase; (2) liposomes loaded with PRL hydrochloride in the aqueous phase; (3) liposomes loaded with PRL base in the lipophilic phase; and (4) "double-loaded" liposomes, containing free PRL base in the membrane bilayer and its HP CD complex in the aqueous compartment. All batches were characterized for particle size, charge, deformability, and entrapment efficiency from using, respectively, light scattering, extrusion, and dialysis techniques, while the anesthetic effect was evaluated in vivo on Guinea pigs, according to the test of dorsal muscle contraction.

Preparation and solid-state characterization of bupivacaine hydrochloride cyclodextrin complexes aimed for buccal delivery.

Binary products of bupivacaine hydrochloride (BVP HCl), an amide type local anesthetic, with parent beta-cyclodextrin (beta-CD) and its soluble beta-cyclodextrin-epichlorohydrin polymer (EPI-beta-CD) were prepared and evaluated as a first phase in the development of a novel mucoadhesive formulation aimed for buccal delivery of this drug. The solid products were obtained by physical mixing, ball milling in high-energy mills, co-evaporation and lyophilisation, in order to rationally select the most effective preparation technique. The solid products obtained were carefully characterised by differential scanning calorimetry (DSC), X-ray powder diffractometry (XRPD), Fourier transform infrared spectroscopy (FTIR) and environmental scanning electron microscopy (ESEM).