Effect of temperature increase during the tableting of pharmaceutical materials

Scale-up of tableting process is particularly difficult due to specific concerns related exclusively to the process itself and that cannot be determined on a smaller scale, which are the effect of compression speed and the build-up of heat due to the length of the compaction operations. In this work, it has been simulated the rise of temperature observed during the tablets manufacturing in a full production scale by means of an appropriate modification of a R&D rotary tablet machine. Four common pharmaceutical excipients, characterized by different chemical nature, consolidation behaviour and temperature sensitiveness have been analysed in terms of compaction mechanism (Heckel and energy analysis) and tabletability, in order to verify any effect of the increase of temperature. The results showed a relevance of the temperature on mechanical tablets properties only on materials characterized by low temperature thermal transitions (melting or glass transition), while, for compounds which do not exhibit thermal events at low temperature, it becomes less important for ductile materials and irrelevant for brittle materials. Heckel analysis highlighted a noticeable increase of ductility only in those materials whose tablets mechanical properties depended on the temperature. On the other hand, energy analysis showed low sensitivity failing to identify any temperature effect on compaction materials properties. This work showed how to simulate the process of temperature rise on a small scale and the influence of temperature on materials compaction properties. The use of a modified tableting machine, able to control the temperature and moisture levels and also capable of monitoring the punch movements, resulted in identifying the effect of temperature both on mechanical and compaction properties on materials. Thus, it represents a valuable tool in order to provide useful information at an early stage during the development of tablets formulations

Dynamic mechanical thermal analysis of hypromellose 2910 free films

It is common practice to coat oral solid dosage forms with polymeric materials for controlled release purposes or for practical and aesthetic reasons. Good knowledge of thermo-mechanical film properties or their variation as a function of polymer grade, type and amount of additives or preparation method is of prime importance in developing solid dosage forms. This work focused on the dynamic mechanical thermal characteristics of free films of hypromellose 2910 (also known as HPMC), prepared using three grades of this polymer from two different manufacturers, in order to assess whether polymer chain length or origin affects the mechanical or thermo-mechanical properties of the final films. Hypromellose free films were obtained by casting their aqueous solutions prepared at a specific concentrations in order to obtain the same viscosity for each. The films were stored at room temperature until dried and then examined using a dynamic mechanical analyser. The results of the frequency scans showed no significant differences in the mechanical moduli E' and E" of the different samples when analysed at room temperature; however, the grade of the polymer affected material transitions during the heating process. Glass transition temperature, apparent activation energy and fragility parameters depended on polymer chain length, while the material brand showed little impact on film performance

Hyperlipidemia control using the innovative association of lupin proteins and chitosan and α-cyclodextrin dietary fibers: food supplement formulation, molecular docking study, and in vivo evaluation

A dietary supplement potentially employed for the treatment and/or prevention of hyperlipidemia was developed. The proposed product is composed of a combination of natural macromolecules as chitosan (CH), α-cyclodextrin (α-CD), and lupin proteins (LP). First, the anti-hyperlipidemic effect of the α-CD and LP binary mixture was assessed and compared to that of the extensively utilized anti-hyperlipidemic CH, using a hyperlipidemic rat model. The anti-hyperlipidemic effect of their combination was also demonstrated. Additionally, ligand–target and protein–protein docking studies were performed. The in vivo results displayed that on intergroup comparison, blending CH, α-CD, and LP promised a superior therapeutic effect over α-CD and LP mixture, CH, and the marketed atorvastatin, potentiating a considerable reduction of serum lipid profile and the calculated atherogenic risk predictor indices. Molecular docking study revealed a weak hydrophobic cholesterol–CH and cholesterol–α-CD interactions, while protein–protein docking study showed a good lipase–LP interaction, involving eight hydrogen bonds. Then, on the base of the in vivo and docking study results, a tablet formulation was produced aimed to overcome the negative technological effects of the anti-hyperlipidemic macromolecules: long disintegration time and tablets mechanical resistance. The optimized tablet formulation has a disintegration time shorter than 15 min and a weight loss from friability test lower than 1%, which are in line with the regulatory specifications for uncoated tablets. Overall, this anti-hyperlipidemic formulation is attractive for the dietary and nutraceutical market, despite further clinical studies are required to assess the efficacy, possible side effects, and product compliance

Permeability-enhancing effects of three laurate-disaccharide monoesters across isolated rat intestinal mucosae

Laurate (C12)-sucrose esters are established intestinal epithelial permeation enhancers (PEs) with potential for use in oral delivery. Most studies have examined blends of ester rather than specific monoesters, with little variation on the sugar moiety. To investigate the influence of varying the sugar moiety on monoester performance, we compared three monoesters: C12-sucrose, C12-lactose, and C12-trehalose. The assays were: critical micellar concentration (CMC) in Krebs-Henseleit buffer, MTS and lactate dehydrogenase assays in Caco-2 cells, transepithelial electrical resistance (TEER) and apparent permeability coefficient (Papp) of [14C] mannitol across isolated rat intestinal mucosae, and tissue histology. For CMC, the rank order was C12-trehalose (0.21 mM) < C12-sucrose (0.34 mM) < C12-lactose (0.43 mM). Exposure to Caco-2 cells for 120 min produced TC50 values in the MTS assay from 0.1 to 0.4 mM. Each ester produced a concentration-dependent decrease in TEER across rat mucosae with 80% reduction seen with 8 mM in 5 min, but C12-trehalose was less potent. C12-sucrose and C12-lactose increased the Papp of [14C] mannitol across mucosae with similar potency and efficacy, whereas C12-trehalose was not as potent or efficacious, even though it still increased flux. In the presence of the three esters, gross intestinal histology was unaffected except at 8 mM for C12-sucrose and C12-lactose. In conclusion, the three esters enhanced permeability likely via tight junction modulation in rat intestinal tissue. C12-trehalose was not quite as efficacious, but neither did it damage tissue to the same extent. All three can be considered as potential PEs to be included in oral formulations

Prunus spinosa extract loaded in biomimetic nanoparticles evokes in vitro anti-inflammatory and wound healing activities

Prunus spinosa fruits (PSF) contain different phenolic compounds showing antioxidant and anti-inflammatory activities. Innovative drug delivery systems such as biomimetic nanoparti-cles could improve the activity of PSF extract by promoting (i) the protection of payload into the lipidic bilayer, (ii) increased accumulation to the diseased tissue due to specific targeting properties, (iii) improved biocompatibility, (iv) low toxicity and increased bioavailability. Using membrane proteins extracted from human monocyte cell line THP-1 cells and a mixture of phospholipids, we formulated two types of PSF-extract-loaded biomimetic vesicles differing from each other for the presence of either 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) or 1,2-dioleoyl-sn-glycero-3-phospho-(1\u2032-rac-glycerol) (DOPG). The biological activity of free extract (PSF), compared to both types of extract-loaded vesicles (PSF-DOPCs and PSF-DOPGs) and empty vesicles (DOPCs and DOPGs), was evaluated in vitro on HUVEC cells. PSF-DOPCs showed preferential incorporation of the extract. When enriched into the nanovesicles, the extract showed a significantly increased anti-inflammatory activity, and a pronounced wound-healing effect (with PSF-DOPCs more efficient than PSF-DOPG) compared to free PSF. This innovative drug delivery system, combining nutraceuti-cal active ingredients into a biomimetic formulation, represents a possible adjuvant therapy for the treatment of wound healing. This nanoplatform could be useful for the encapsulation/enrichment of other nutraceutical products with short stability and low bioavailability

Toxicological profiles and surface properties at physiological pH of N-decanoyl amino acids

Meeting title: From Food to Pharma: the polyhedral nature of polymersPURPOSE: N-acyl amino acids based surfactants are an attractive class of anionic amphiphiles alternative to sulphate-based surfactants potentially employed as excipients in all pharmaceutical applications at which an anionic surfactant (eg. sodium dodecyl sulphate SDS) is needed (1, 2). The aim of this work is to correlate surface properties of N-decanoyl amino acids at physiological pH and their toxicological profile in order to explore the potential use of these surfactants for …postprin

PEGylated systems in pharmaceutics

This review addresses the use of poly(ethylene glycol) (PEG) and PEG conjugation for the design of novel dosage forms and the modification of biomolecules. The peculiarities of PEGylated nanoparticles, liposomes, proteins, enzymes, and small drug and polyelectrolyte molecules and their influence on systemic drug delivery, including overcoming of various biological barriers and adhesion to mucosal tissues (mucoadhesion), are considered

Characterization of the interaction between chitosan and inorganic sodium phosphates by means of rheological and optical microscopy studies

The physicochemical and rheological properties of chitosan and two different inorganic sodium phosphate dispersions (NaH 2PO 4 and Na 3PO 4) were investigated in order to elucidate the role of different factors, such as ratios between polymer and sodium inorganic phosphates, different pHs and storage stability, on the gelling properties of chitosan. This was deemed opportune since physico-chemical characterizations of chitosan in the literature often appear incomplete and questionable. We also compared the elastic modulus values of the different chitosan/inorganic phosphate systems and examined their behaviour through optical microscopy analyses. The most efficient formulations that showed a thermogelling capacity with a significant gel transition behaviour after 24 h were the NaH 2PO 4/chitosan and Na 3PO 4/chitosan systems at ratio 2 and pH 7.0. These results confirmed the importance of the pH value and ratio selection for the final systems

ORAC of chitosan and its derivatives

Chitosan and chitosan derivatives are receiving a lot of attention as materials of natural origin which possess radical scavengers, antioxidants and antimicrobial properties, especially in food applications. With the aim to apply the Oxygen-Radical Absorbance Capacity assay (ORAC), to detect the polysaccharides capacity to scavenge the peroxyl radical, four different grafted chitosan derivatives were synthesized.Among the synthesized derivatives, N-acetyl cysteine-g-chitosan was found to have the highest ORAC value, while gallic acid-g-chitosan and p-hydroxybenzoic acid-g-chitosan had respective 70% and 42% of ORAC values of the former. On the contrary, p-methoxybenzoic acid-g-chitosan did not show any significant difference in antioxidant activity from the unmodified chitosan. A linear correlation between ORAC values and total phenols measured with the Folin-Ciocalteau reagent was shown. The combination of ORAC and Folin-Ciocalteau assays is a useful system to monitor the growth of the acquired antioxidant capacity in relation to the type of phenolic compound used for grafting

Chitosans as new tools against biofilms formation on the surface of silicone urinary catheters

Urinary catheters contamination by microorganisms is a major cause of hospital acquired infections and represents a limitation for long-term use. In this work, biofilms of Klebsiella pneumoniae and Escherichia coli clinical isolates were developed on urinary catheters for 48 and 72 h in artificial urine medium (AUM) with different molecular weight chitosans (AUM-CS solutions) at pH 5.0. The number of viable bacteria was determined by standard plate count agar while crystal violet (CV) staining was carried out to assess biomass production (optical density at 570 nm) in the mentioned conditions. Re-growth of each strain was also evaluated after 24 h re-incubation of the treated catheters. Significant decreases of log CFU/catheter and biomass production were observed for all the biofilms developed in AUM-CS compared with the controls in AUM. The percentages of biofilm removal were slightly higher for E. coli biofilms (up to 90.4%) than those of K. pneumoniae (89.7%); in most cases, the complete inhibition of bacterial re-growth on treated catheter pieces was observed. Contact time influenced chitosan efficacy rather than its molecular weight or the biofilms age. The results confirmed the potentiality of chitosans as a biomacromolecule tool to contrast biofilm formation and reduce bacterial re-growth on urinary catheters