FORMULATION AND PREPARATION OF ORALLY DISINTEGRATING TABLETS USING INNOVATIVE BINDER

Abstract The present study investigates the use of glyceryl palmitostearate (Precirol ATO 5 -coded PATO) as binder in orally disintegrating tablets (ODT), prepared by melt granulation. PATO has been mentioned in literature for its lipophilic nature and fine powder properties, providing excelent coating and slow release of active drugs, but it can also be used for taste masking purposes, with possible applications in ODT. In order to use it as an ODT excipient, some challenges must be overcome, given its lipophilicity. Our first goal was to study its potential to improve tablet properties (hardness, friability, disintegration time) and provide fast release of the model drug, by setting the optimal proportion to be used in ODT. We investigated a complete 3 3 experimental design with 9 formulations containing 300 mg acetaminophen; the independent variables were: proportion of PATO binder (2.5-7.5 %) and proportion of sodium starch glycolate (Explotab) as superdisintegrant (5-10 %). The regression equations and response surface plots showed the validity of the model, and a significant influence of PATO on the response variables: tablet hardness, disintegration time, and active drug release in a short time. We can conclude that Precirol ATO 5 can be used as binder in ODT (not more than 5 %), higher proportions having a slow-release effect. Also, together with 8 % disintegrant, it provides good tablet properties, fast disintegration and a release of 80 % acetaminophen after 10 min. Rezumat Studiul investighează utilizarea excipientului glicerol palmitostearat (Precirol ATO 5-PATO) ca liant în comprimatele orodispersabile (ODT) preparate prin metoda melt granulation. PATO are proprietăţi lipofile accentuate şi o fineţe avansată a pulberii, fiind recomandat în literatură ca agent de acoperire, dar şi de retardare în comprimate; el poate fi utilizat şi ca agent de mascare a gustului, aplicaţie utilă în formularea ODT. Utilizarea lui în ODT trebuie să depăşească inconvenientele legate de lipofilia sa, păstrând calităţile care pot fi utile în acest tip de formulare: îmbunătăţirea proprietăţilor comprimatelor (duritate, friabilitate, timp de dezagregare) şi o cedare accelerată a substanţelor active, prin stabilirea unei proporţii optime de PATO care să asigure calităţile menţionate. Ca substanţă-model s-a ales paracetamolul (300 mg/comprimat) şi s-a construit un plan experimental complet 3 3 cu 9 experimente, în care variabilele independente au fost proporţile de PATO (2,5-7,5 %) şi amidon glicolat de sodiu ca dezagregant (5-10 %). Ecuaţiile de regresie şi suprafeţele de răspuns au confirmat validitatea modelului ales, liantul PATO influenţând proprietăţile FARMACIA, 2013, Vol. 61, 6 1132 comprimatelor, dar şi cedarea paracetamolului. Putem concluziona că liantul Precirol ATO 5 este util în ODT în proporţia maximă de 5 %, peste această limită manifestând un efect de încetinire a cedării. Asociat cu 8 % dezagregant asigură proprietăţi corespunzătoare pentru ODT şi o cedare a paracetamolului de 80 % după 10 minute

An Accessible Method to Improve the Stability and Reusability of Porcine Pancreatic α-Amylase via Immobilization in Gellan-Based Hydrogel Particles Obtained by Ionic Cross-Linking with Mg²⁺ Ions

Amylase is an enzyme used to hydrolyze starch in order to obtain different products that are mainly used in the food industry. The results reported in this article refer to the immobilization of α-amylase in gellan hydrogel particles ionically cross-linked with Mg2+ ions. The obtained hydrogel particles were characterized physicochemically and morphologically. Their enzymatic activity was tested using starch as a substrate in several hydrolytic cycles. The results showed that the properties of the particles are influenced by the degree of cross-linking and the amount of immobilized α-amylase enzyme. The temperature and pH at which the immobilized enzyme activity is maximum were T = 60 °C and pH = 5.6. The enzymatic activity and affinity of the enzyme to the substrate depend on the particle type, and this decreases for particles with a higher cross-linking degree owing to the slow diffusion of the enzyme molecules inside the polymer’s network. By immobilization, α-amylase is protected from environmental factors, and the obtained particles can be quickly recovered from the hydrolysis medium, thus being able to be reused in repeated hydrolytic cycles (at least 11 cycles) without a substantial decrease in enzymatic activity. Moreover, α-amylase immobilized in gellan particles can be reactivated via treatment with a more acidic medium

Curcumin-loaded polysaccharides-based complex particles obtained by polyelectrolyte complexation and ionic gelation. I-Particles obtaining and characterization

International audienc

Polysaccharides-Based Complex Particles’ Protective Role on the Stability and Bioactivity of Immobilized Curcumin

International audienceThe curcumin degradation represents a significant limitation for its applications. The stability of free curcumin (FC) and immobilized curcumin in complex particles (ComPs) based on different polysaccharides was studied under the action of several factors. Ultraviolet-visible (UV-VIS) and Fourier-transform infrared (FTIR) spectroscopy proved the FC photodegradation and its role as a metal chelator: 82% of FC and between 26% and 39.79% of curcumin within the ComPs degraded after exposure for 28 days to natural light. The degradation half-life (t1/2) decreases for FC when the pH increases, from 6.8 h at pH = 3 to 2.1 h at pH = 9. For curcumin extracted from ComPs, t1/2 was constant (between 10 and 13 h) and depended on the sample’s composition. The total phenol (TPC) and total flavonoids (TFC) content values increased by 16% and 13%, respectively, for FC exposed to ultraviolet light at λ = 365 nm (UVA), whereas no significant change was observed for immobilized curcumin. Antioxidant activity expressed by IC50 (µmoles/mL) for FC exposed to UVA decreased by 29%, but curcumin within ComPs was not affected by the UVA. The bovine serum albumin (BSA) adsorption efficiency on the ComPs surface depends on the pH value and the cross-linking degree. ComPs have a protective role for the immobilized curcumin

Impact of the Liquid Crystal Order of Poly(azomethine-sulfone)s on the Semiconducting Properties

Organic semiconductors are an attractive class of materials with large application in various fields, from optoelectronics to biomedicine. Usually, organic semiconductors have low electrical conductivity, and different routes towards improving said conductivity are being investigated. One such method is to increase their ordering degree, which not only improves electrical conduction but promotes cell growth, adhesion, and proliferation at the polymer–tissue interface. The current paper proposes a mathematical model for understanding the influence of the ordering state on the electrical properties of the organic semiconductors. To this end, a series of aromatic poly(azomethine)s were prepared as thin films in both amorphous and ordered states, and their supramolecular and electrical properties were analyzed by polarized light microscopy and surface type cells, respectively. Furthermore, the film surface characteristics were investigated by atomic force microscopy. It was established that the manufacture of thin films from mesophase state induced an electrical conductivity improvement of one order of magnitude. A mathematical model was developed in the framework of a multifractal theory of motion in its Schrodinger representation. The model used the order degree of the thin films as a fractality measure of the physical system’s representation in the multifractal space. It proposed two types of conductivity, which manifest at different ranges of fractalization degrees. The mathematical predictions were found to be in line with the empirical data

Topical formulations containing aptamer-functionalized nanocapsules loaded with 5-fluorouracil - An innovative concept for the skin cancer therapy

New topical gel formulations based on sodium alginate and hyaluronic acid containing AS1411 aptamer-functionalized polymeric nanocapsules loaded with an antitumoral drug (5-Fluorouracil) were designed as an innovative approach for the skin cancer treatment. Several important analyses were used to characterize these obtained topical gel formulations, namely: rheological tests, permeation assays across Strat-M® artificial membrane, ex-vivo permeation assays across chicken skin membrane, haemolysis tests, skin irritation tests, in vitro cytotoxicity assay on human basal carcinoma cells and in vivo tests. Rheological tests revealed that apparent viscosity decreases with the increase of the shear rate, for analyzed samples, which demonstrates a shear thinning behavior. Low levels of hemolysis values which ranged between 0.03 and 0.55% suggested that the tested formulations did not induce red blood cell lysis.. The gel formulations containing nanocapsules loaded with 5-FU proved to be non-irritant. Furthermore, by study the ex-vivo diffusion properties across the chicken skin membrane, it was proved that nanoencapsulation enhance the permeability properties of 5-FU. In vitro cytotoxicity assay on TE 354.T (ATCC® CRL-7762™) human basal carcinoma cell line showed that the obtained formulations loaded with 5-Fluorouracil manifest an important cytotoxic effect. Finally, the presence of Langerhans CD68 cells-positive in the epidermis and epithelial sheath of dermal hair follicles suggests a specific activation, migration and retrieval of nanoparticles by these cells. Following the results obtained in this study we can appreciate that the obtained topical gel formulations have a favourable biosafety and good antitumor effects which makes them attractive for skin cancer treatment

Biomaterials Based on Chitosan and Polyvinyl Alcohol as a Drug Delivery System with Wound-Healing Effects

The excellent biological properties of chitosan (CS) together with the increased oxygen permeability of polyvinyl alcohol (PVA) were the prerequisites for the creation of a wound healing dressing that would also function as a system for L-arginine (L-arg) and caffeine (Caff) delivery. Using the freezing/thawing method, 12 hydrogels were obtained in PVA:CS polymer ratios of 90:10, 75:25, and 60:40, and all were loaded with L-arg, Caff, and the mixture of L-arg and Caff, respectively. Afterwards, an inorganic material (zeolite–Z) was added to the best polymeric ratio (75:25) and loaded with active substances. The interactions between the constituents of the hydrogels were analyzed by FTIR spectroscopy, the uniformity of the network was highlighted by the SEM technique, and the dynamic water vapor sorption capacity was evaluated. In the presence of the inorganic material, the release profile of the active substances is delayed, and in vitro permeation kinetics proves that the equilibrium state is not reached even after four hours. The synergy of the constituents in the polymer network recommends that they be used in medical applications, such as wound healing dressings