The aim of the present work was to optimize the process parameters of the nano spray drying technique for the formulation of benzydamine-loaded casein nanoparticles and to investigate the effect of some process variables on the structural and morphological characteristics and release behavior. The obtained particles were characterized in terms of particle size and size distribution, surface morphology, production yield and encapsulation efficiency, drug-polymer compatibility, etc., using dynamic light scattering, scanning electron microscopy, differential scanning calorimetry, and Fourier transformed infrared spectroscopy. Production yields of the blank nanoparticles were significantly influenced by the concentration of both casein and the crosslinking agent. The formulated drug-loaded nanoparticles had an average particle size of 135.9 nm to 994.2 nm. Drug loading varied from 16.02% to 57.41% and the encapsulation efficiency was in the range 34.61% to 78.82%. Our study has demonstrated that all the investigated parameters depended greatly on the polymer/drug ratio and the drug release study confirmed the feasibility of the developed nanocarriers for prolonged delivery of benzydamine.

This research aims to investigate the properties of nano- and micro-sized casein hydrogels crosslinked by sodium tripolyphosphate as drug delivery systems. Benzydamine hydrochloride was chosen as a model hydrophilic drug. The gels were synthesized by varying different parameters: casein concentration, casein/crosslinking ratio, and addition of ethanol as a co-solvent. The electrostatic attractive interactions between the casein and the sodium tripolyphosphate were confirmed by FTIR spectroscopy. The particle sizes was determined by dynamic light scattering and varied in the range between several hundred nanometers and several microns. The yield of the gelation process was high for all investigated samples and varied between 55.3% and 78.3%. The encapsulation efficiency of the particles was strongly influenced by the casein concentration and casein/crosslinker ratio and its values were between 4.6% and 22.4%. The release study confirmed that casein particles are useful as benzydamine carriers and ensured prolonged release over 72 h.

The aim of the present research is the preparation of chitosan nanoparticles intended for Benzydamine (BZ) delivery. The method of ionotropic gelation is applied for the nanoparticle's formation. The crosslinking is performed by NaTPP. Dynamic light scattering analysis shows that particle's sizes are in nano‐scale and can be varied by changing the polymer and crosslinker concentrations. The yield of the gelation varies between 23% and 69%. The BZ loading efficiency differs in the range from 10% to 24.3%. Differential scanning calorimetry is applied for investigating the BZ state. It proved that the BZ changes its physical state from crystal to amorphous. The in vitro drug release profile along with kinetics and mechanism of release from the nano‐spheres are studied under simulated physiological conditions for different incubation periods. The release rate can be changed by varying the chitosan and NaTPP concentrations.

Hydrogels from natural polyelectrolytes possess many important features such as low toxicity, biocompatibility, biodegradability and hydrophilicity. These properties make them very suitable for applications such as immobilization and controlled release of drugs and other types of biologically active molecules. In the present study submicron-sized hydrogels made from casein by ionotropic gelation are investigated. For this purpose, two types of crosslinking agents are used at different pH conditions. In order to characterize these submicron gels, their sizes, chemical structures and thermal stability are examined by dynamic light scattering (DLS), FT-IR and Differential Scanning calorimetry (DSC) respectively. To prove their immobilization ability, active compound, namely curcumin, is immobilized in the hydrogel’s structures. DPPH assay is conducted to establish the antioxidant properties of the curcumin before and after the immobilization. The loading efficiency of the nanostructures together with the curcumin release kinetics are evaluated and modelled mathematically.

The objectives of the present study were to synthesize casein/chitosan nanocomplexes, which are able to immobilize and release Benzydamine in a controlled manner, and to investigate the influence of casein/chitosan ratio on their morphological, physico-chemical and drug carrier characteristics. The complexes were obtained by electrostatic interaction at pH 6, at which casein in negatively charged and chitosan is protonated. The yield of the complexation was the lowest for chitosan excess particles (18.4%) and increased to 83.5% for casein excess particles. The particle size varied in the range from 400 nm to several microns depending on the casein/chitosan ratio. Atomic force microscopy (AFM) was used to assess the morphological properties of the nanocomplexes. It was found that the Benzydamine loading was minimal (15%) in the stoichiometric complex and maximal (30%) in complexes with casein/chitosan ratio 5:1. The mechanism of Benzydamine release was defined as Fickian diffusion.

Particles based on emulsified chitosan in oil phase have been reported in the present study. Sodium Tripolyphosphate (NaTPP) was introduced to them as a crosslinker and its effect on their properties was examined. Laser diffraction technique showed that the obtained structures are micronsized particles with single modal distribution. Optical microscopy has confirmed their size range, together with the fact that their shape is regular and spherical. Swelling studies in simulated saliva conditions (pH = 6.8) has shown a relation between the crosslinking degree of the particles and cycles of swelling and dissolution at different rates. Mucoadhesion test confirmed their potential as delivery systems through a mucosal route and showed dependence of the mucoadhesion properties upon the free amino groups left onto the chitosan chains.

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The derivation of structural characteristics of a compound of unknown structure from its spectral data is a central procedure for modern structure elucidation. Computer searching in spectral libraries of fully-assigned 13 C NMR spectra of substructures or full structures is an essential part of structure elucidation and has been widely applied because this type of spectra reflects the nature of the skeletal backbone of an organic compound, information not as readily available by other spectroscopic techniques [1]. In this paper we describe an extensive test of a previously developed method for interpretive search in spectral libraries of fully-assigned 13 C NMR spectra [2]. The method is implemented into a Windows-based userfriendly program, called Infer C NMR.The program input consists of the 13 C NMR spectrum of the unknown compound (chemical shift and multiplicity of each signal) and molecular formula. The search algorithm retrieves a list of connected substructures from the reference compounds in such a way that only atoms with matched signals are included into the inferred substructures. The substructures are explicitly defined in terms of atom type, hydrogen multiplicity, and bond type. They are presented embedded into the reference structures and are sorted according to their reliability (estimation of their correctness, usually called accuracy). This accuracy is calculated by a multivariate function that was obtained in advance by comprehensive statistics. The parameters that restrict the search algorithm are the tolerance of signal matching (Tol) in ppm and the minimum number of carbon atoms in the inferred (retrieved) substructures (m.n.c.); the latter is set to six for this study.Although our program for interpretive library search is intended to serve as a useful stand-alone application for the spectroscopist, its output can be sent as input to a computer-enhanced structure elucidation system, such as SESAMI [3]. In this mode, one or more of the retrieved substructures act as constraints on the structure generation process, serving to reduce the number of plausible alternative structures that are presented to the chemist by the structure generator. The greater the number and information content of the constraints, the greater the efficiency of the structure generator and the fewer the structures produced. It is important to recognize that if a substructure predicted as present is handed to the structure generator, every structure output will contain that substructure. Thus, if even only one of the retrieved substructures used as constraints is incorrect, every structure produced by structure generator will be invalid (the worst scenario) or no output structures will be generated because the constraints contradict each other or other spectral data (a better scenario). That is why the output from the interpretive 13 C NMR library search must have two very important features: high information content and high reliability.As described in a previous paper [2], the accuracy function was tested with a large ...