Angela Abruzzo

Freeze-dried chitosan/pectin nasal inserts for antipsychotic drug delivery

The objective of this investigation was the development of chitosan/pectin based nasal inserts to improve bioavailability of antipsychotic drugs in the treatment of psychotic symptoms. In fact, the nasal route of administration ensures systemic availability avoiding the first-pass metabolism and obtaining more efficacious treatments. Chitosan/pectin polyelectrolyte complexes were prepared at pH 5.0 with different polycation/polyanion molar ratios and lyophilized in small inserts in the presence of chlorpromazine hydrochloride. The results show that higher amount of pectin in the complexes, with respect to higher amount of chitosan, produced a more evident porous structure of the nasal inserts, improving water uptake ability and mucoadhesion capacity. Finally, the presence of increasing amounts of pectin allowed the interaction with chlorpromazine hydrochloride inducing the formation of less hydratable inserts thus limiting drug release and permeation. This investigation verifies the formation of polyelectrolyte complexes between chitosan and pectin at pH values in the vicinity of the pKa interval of the two polymers and confirms the potential of these complexes, capable of achieving antipsychotic drug delivery in the nasal cavity.

Chitosan/alginate complexes for vaginal delivery of chlorhexidine digluconate

Chitosan/alginate complexes were prepared at different polycation/polyanion molar ratios and freeze-dried vaginal inserts were obtained for chlorhexidine digluconate local delivery in genital infections. Complex yield, FT-IR spectra, and TGA thermograms were studied to confirm the interaction between the two polyions. The influence of different complexes on physical handling, morphology, and drug distribution in the samples were evaluated by friability test, scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS), respectively. In vitro water-uptake, mucoadhesion and release tests were performed as well as microbiological tests toward pathogenic vaginal microorganisms. The results showed that the selection of suitable chitosan/alginate molar ratio and drug loading allowed modulate insert ability to hydrate, adhere to the mucosa, and release chlorhexidine digluconate. The insert containing an excess of alginate was found to be the best performing formulation and showed good antimicrobial activity toward the pathogens Candida albicans and Escherichia coli.

Chitosan based micro- and nanoparticles for colon-targeted delivery of vancomycin prepared by alternative processing methods

The aim of this work was to prepare chitosan (CH) based particulate formulations for colon delivery of vancomycin (VM). Chitosan microparticles (MPs) and nanoparticles (NPs) loaded with VM were prepared using different CH/tripolyphosphate (TPP) molar ratios and different technological processes. In particular, nanoparticles were prepared by ionic gelation and freeze-drying to recover these particles, or, alternatively, by spray-drying method. Microparticles were prepared using a different spray-dryer. Micro- and nanoparticles were characterized in terms of size distributions by photon correlation spectroscopy (PCS), while encapsulation and drug loading efficiencies were studied using a dialysis method. Fourier Transform Infrared Spectroscopy (FT-IR) was employed to determine the surface composition of the micro- and nanoparticles respectively, and the morphologies of the developed systems were studied by scanning electron microscopy (SEM). Water uptake as well as drug release profiles were also measured. Antibacterial activity against Staphylococcus aureus, a Gram-positive model strain, was evaluated. FT-IR results suggested an electrostatic interaction between VM and CH/TPP particles. Moreover, the particles were found to hold a positive zeta-potential, indicating the presence of CH on the particle surfaces. Particle size and encapsulation efficiency were mainly influenced by the different manufacturing processes employed. Nanoparticles obtained by spray-drying showed the best results in terms of water uptake and drug release rate. Moreover, they showed a good bactericidal activity against S. aureus.

Vaginal inserts based on chitosan and carboxymethylcellulose complexes for local delivery of chlorhexidine: preparation, characterization and antimicrobial activity.

The aim of this work was to prepare vaginal inserts based on chitosan/carboxymethylcellulose polyelectrolyte complexes for local delivery of chlorhexidine digluconate. Complexes were prepared with different chitosan/carboxymethylcellulose molar ratios at a pH value close to pKa interval of the polymers and were characterized in terms of physico-chemical properties, complexation yield and drug loading. Then complexes were used to prepare inserts as vaginal dosage forms and their physical handling, morphology, water-uptake ability and drug release properties as well as antimicrobial activity toward Candida albicans and Escherichia coli were evaluated. Results confirmed the ionic interaction between chitosan and carboxymethylcellulose and the influence of the charge amount on the complexation yield. Complexes were characterized by high values of drug loading and showed increasing water-uptake ability with the increase of carboxymethylcellulose amount. The selection of appropriate chitosan/carboxymethylcellulose molar ratios allowed to obtain cone-like shaped solid inserts, easy to handle and able to hydrate releasing the drug over time. Finally, the formulated inserts showed antimicrobial activity against common pathogens responsible for vaginal infections.

Microparticles based on chitosan/carboxymethylcellulose polyelectrolyte complexes for colon delivery of vancomycin.

The aim of this work was to prepare polyelectrolyte complexes based on chitosan (CH) and carboxymethylcellulose (CMC) for colon delivery of vancomycin (VM). Various batches of polyelectrolyte complexes, using three different CH/CMC weight ratios (3:1, 1:1 and 1:3), were prepared and collected as microparticles by spray-drying process. Microparticles were characterized in terms of yield, encapsulation efficiency, drug loading, morphology and mucoadhesion properties. Microparticles water-uptake and VM release as well as its protection against gastric pepsin degradation were also investigated. Finally, the antibacterial activity against Staphylococcus aureus, a Gram-positive model strain, was evaluated. The best formulation CH/CMC 1:3 was selected based on the encapsulation efficiency, water-uptake and drug release rate. Moreover, microparticles were able to prevent VM degradation and showed a good antibacterial activity against S. aureus. Finally, to improve the release of VM in the colon the selected formulation was coated with lauric acid.

Mucoadhesive Buccal Tablets Based on Chitosan/Gelatin Microparticles for Delivery of Propranolol Hydrochloride.

Propranolol administration through buccal route offers some distinct advantages thanks to the easy access to the oral mucosa, fast onset of action, and avoidance of hepatic and intestinal degradation mechanisms. To overcome the effective removal existing in the buccal cavity, mucoadhesive delivery systems are considered a promising approach as they facilitate a close contact with the buccal mucosa. The aim of this study was to prepare mucoadhesive tablets based on chitosan/gelatin microparticles for buccal delivery of propranolol hydrochloride. Spray-dried microparticles were prepared with different chitosan-gelatin weight ratios and characterized in terms of yield and morphology. Microparticles were subsequently compressed with the drug to obtain loaded buccal tablets. In vitro water uptake, mucoadhesion, release, and permeation tests were performed to investigate tablet ability to hydrate, to adhere to the mucosa, and to deliver drug through buccal mucosa. Microparticles showed a different morphology based on the different chitosan-gelatin weight ratios. Moreover, buccal tablets based on the prepared microparticles showed different technological and functional characteristics in virtue of their composition. In particular, tablets with an excess of chitosan showed the best mucoadhesive properties, allowed the permeation of the greatest drug amount among all formulations, and could be promising for buccal administration of propranolol hydrochloride.

Development and characterization of chitosan/hyaluronan film for transdermal delivery of thiocolchicoside

The objective of this study was the development of chitosan/hyaluronan transdermal films to improve bioavailability of thiocolchicoside. This approach offers the possibility to elude the first-pass metabolism and at the same time it is able to provide a predictable and extended duration of activity. Films were prepared by casting and drying of aqueous solutions containing different weight ratios of chitosan and hyaluronan and characterized for their physico-chemical and functional properties. In accordance with polymeric composition of films and, therefore, with the amount of the net charge after the complexation, films containing the same weight ratio of chitosan and hyaluronan showed lower water uptake ability with respect to films containing only one polymeric species or an excess of chitosan or hyaluronan. Moreover, the lower the hydration of the polymeric network, the lower is the drug diffusion through the films and its permeation through the skin. This study clearly confirmed that the selection of a suitable polymeric weight ratio and appropriate preparative conditions allows the modulation of film functional properties, suggesting that these formulations could be used as a novel technological platform for transdermal drug delivery.

Design and evaluation of buccal films as paediatric dosage form for transmucosal delivery of ondansetron

In the process of implementation and innovation of paediatric dosage forms, buccal films for transmucosal administration of drug represent one of the most interesting approach. In fact, films are able to provide an extended duration of activity allowing minimal dosage and frequency and offer an exact and flexible dose, associated with ease of handling. The objective of the present study was to develop polymeric films for the sustained release of ondansetron hydrochloride, a selective inhibitor of 5-HT3 receptors indicated in paediatrics for the prevention and treatment of nausea and vomiting caused by cytotoxic chemotherapy or radiotherapy and postoperatively. Films were prepared by casting and drying of aqueous solutions containing different weight ratios of hydroxypropylmethylcellulose (HPMC) with chitosan (CH) or sodium hyaluronate (HA) or gelatin (GEL) and characterized for their physico-chemical and functional properties. The presence of HA, GEL and CH did not improve the mucoadhesive properties of HPMC film. The inclusion of GEL and CH in HPMC film increased in vitro drug release with respect to the inclusion of HA, although films containing HA showed the highest water uptake. Moreover in agreement with the release behaviour, the inclusion of CH and GEL provided higher drug permeation through porcine buccal mucosa with respect to HPMC film and ensured linear permeation profiles of drug.

Recent progress on curcumin-based therapeutics: a patent review (2012-2016). Part I: Curcumin

ABSTRACT Introduction: curcumin is the main bioactive component contained in Curcuma Longa, largely employed in traditional medicine. Recently, beneficial properties, useful for prevention and treatment of several disorders, have been discovered for this compound. Peculiar structural feature is an α,β-unsaturated carbonyl system essential for establishing contacts with critical cysteine residues of several targets. This distinctive mechanism of action imparts to the molecule the ability to affect a large number of targets, accounting for its pleiotropic behaviour and definition of “privileged structure”. Areas covered: The objective of the review is an examination of the recent developments in the field of the anti-cancer applications of curcumin, together with formulation issues, considering the patent literature in the years 2012-2016. Expert opinion: The wide therapeutic efficacy of curcumin is related to synergistic interactions with several biological targets, along with the modulation of several signaling pathways. This peculiar behaviour could be useful in the treatment of multifactorial diseases such as cancer. Combination of curcumin with a first line antineoplastic drug proved to be a valuable strategy to obtain an amplified response with minimized side effects. Innovative curcumin formulations based on the nanotechnology approach allowed improving both bioavailability and therapeutic efficacy.

Hydroxypropylmethylcellulose films for prolonged delivery of the antipsychotic drug chlorpromazine.

Objectives The aim of this study was to develop transdermal films based on hydroxypropylmethylcellulose with the purpose of improving transdermal permeation of chlorpromazine hydrochloride, an antipsychotic drug used to alleviate the symptoms and signs of psychosis.