Priprava i evaluacija hidrogela s diazepamom za rektalnu primjenu

Diazepam (DZP) has become a commonly used drug for treatment of acute repetitive epileptic seizures and febrile convulsions in children. Considering the advantages of rectal administration of DZP, the objective of our study was to formulate and evaluate rectal hydrogels containing DZP as a drug substance in combination with suitable co-solvents and preservatives. Prepared HPMC (hydroxypropyl methylcellulose) hydrogels containing different concentrations of DZP (2, 4 and 6 mg mL-1) manifested good quality in respect to physico-chemical parameters (pH value, drug content, ingredients content and viscosity), antimicrobial efficiency and microbiological quality. Under the proposed HPLC conditions, satisfactory separation of DZP and the preservatives used was achieved. In vitro release studies have shown that the total amount of DZP was released in a period of 3 h. Prepared formulations were stable for four months at 26 oC (ambient temperature characteristic of the 2nd climate zone).Diazepam (DZP) je ljekovita tvar koja se upotrebljava u terapiji akutnih epileptičkih napada i febrilnih konvulzija u djece. U radu je opisana priprava i evaluacija hidrogela za rektalnu primjenu s diazepamom i odgovarajućim pomoćnim tvarima i konzervansima. Pripravci su sadržavali različite koncentracije DZP (2, 4 i 6 mg mL-1). Njihova fizičko-kemijska svojstva (pH vrijednost, sadržaj ljekovite i pomoćnih tvari, viskoznost), antimikrobna učinkovitost i mikrobiološka čistoća bili su zadovoljavajući. Razvijena je HPLC metoda kojom je postignuta separcija DZP i konzervansa. In vitro ispitivanja su pokazala da se cjelokupna količina DZP oslobodi tijekom 3 h. Pripravci su bili stabilni 4 mjeseca na temperaturi 26 C (sobna temperatura karakteristična za 2. klimatsku zonu)

Poli(laktid-ko-glikolid) mikročestice kao sustav za kontrolirano oslobađanje proteina: priprava i karakterizacija

Poly(DL-lactide-co-glycolide) (PDLLGA) and poly(L-lactide-co-glycolide) (PLLGA) copolymers were prepared by bulk ring opening polymerization of lactide and glycolide and characterized by GPC, FTIR, 1H NMR and DSC. Copolymers with different molar masses at a constant lactide/glycolide ratio were used for preparation of bovine serum albumin (BSA)-loaded microparticles by the double emulsion w/o/w method. The influence of the copolymer molar mass and composition on the microparticle morphology, size, yield, degradation rate, BSA-loading efficiency and BSA release profile were studied. For microparticles prepared from PDLLGA copolymers, a biphasic profile for BSA release was found and for those made from PLLGA copolymers the release profile was typically triphasic; both of them were characterized by high initial burst release. Possible reasons for such behavior are discussed.Poli(DL-laktid-ko-glikolid) (PDLLGA) i poli(L-laktid-ko-glikolid) (PLLGA) kopolimeri priređeni su polimerizacijom laktida i glikolida uz otvaranje prstenova i karakterizirani pomoću GPC, FTIR, 1H NMR i DSC. Kopolimeri različitih molarnih masa i stalnog omjera laktida i glikolida upotrebljeni su za pripravu mikročestica s goveđim serumskim albuminom (BSA) metodom dvostruke emulzije tipa voda/ulje/voda. Proučavan je utjecaj molarne mase i sastava kopolimera na oblik, veličinu, iskorištenje i stupanj razgradnje mikročestica, uklapanje i oslobađanje BSA. Za mikročestice pripravljene s PDLLGA kopolimerom utvrđen je bifazični profil oslobađanja BSA, a za mikročestice s PLLGA kopolimerom trifazičan profil. Za obje vrste karakteristično je brzo početno oslobađanje. Razmatrani su mogući uzroci takvog ponašanja

Factorial design analysis and optimisation of alginate—Ca-chitosan microspheres

The purpose of this study was to apply factorial design in order to determine the influence of the formulation factors and their interactions on several responses such as particle size, dissolution behaviour at pH 1.2 and pH 7.4 as well as production yield, during the development of budesonide loaded, chitosan coated Ca–alginate microparticles (MPs) intended for treatment of inflammatory diseases in the gastrointestinal tract. Produced drug-loaded MPs were spherical in shape, had smooth surfaces with low porosity and size range between 5 and 11 μm. Production yield for the formulations from the design varied from 19% to 50%. Optimisation was performed using central composite design setting the targets: particle size at 5.5 μm, maximised yield, suppressed dissolution at pH 1.2 and sustained release at pH 7.4. The optimised batches were identified with a combined desirability value of 0.967

Biodegradation and drug release studies of BSA loaded gelatin microspheres

Certain variations in the process parameters (emulsification time, surfactant concentration) were performed in order to prepare BSA-loaded gelatin microspheres with high loading efficacy and particle size ranging from 1 to 10 μm using a procedure originally employed by Tabata and Ikada. The mathematical modelling of drug release in the presence of collagenase showed a biphasic release pattern, where the rate constant for the initial time release confirmed the influence of the particle size and/or enzymatic degradation rate on drug release rate. © 2002 Elsevier Science B.V. All rights reserve

Biopharmaceutical characterization of povidone-iodine liposomes

Different formulations of multilamellar liposomes were prepared from Soya lecithin and poly(l-vinyl-2- pyrrolidone)iodine complex by a mechanical method, vortexing the phospholipid dispersion in water. Biopharmaceu�tical evaluation and antimicrobial efficacy studies were performed in order to evaluate liposome's potential for use as a sustained release depo with efficient and prolonged antimicrobial action, compared to PVP-I solution. Varying the drug/phospholipid ratio during the preparation of the liposomes, different efficacy of PVP-I encapsulation was achieved. Lower concentrations of PVP-I in the lecithin dispersion for liposome preparation resulted with higher in�corporation efficacy. Dissolution test results point that total drug release (%) from the series within 24 hours was 45.08 ± 1.53, 36.15 ± 1.65, 22.54 ± 1.96, 19.98 ± 1.05 for series A, B, C and D, respectively. The in vitro microbi�ological testing demonstrated good antimicrobial efficiency of PVP-I liposome dispersions against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans. Also prolonged antimicrobial action, compared to PVP-I solution was noticed

Micro-Raman Spectroscopy for Detection of Label-Free and Oil Red O Labeled PEGylated Nanoliposomes in hCmec/D3 Cell Internalization Studies

Rapid development of nanomedicines necessitates advancement in internalization techniques which can accurately distinguish between the complex environments of cells and nanocarriers. Internalization (or endocytosis) studies of oil red O labeled and label-free PEGylated-lecithin/cholesterol nanoliposomes was performed using micro-Raman spectroscopy. The C.O stretching vibrations and CCH scissoring bendings of naphthalene ring around 1225 cm.1 as well as the N=N stretching vibrations at 1377 cm.1 are prominent peaks absent from the label-free spectra which can be used for detection of internalized oil red O labeled nanoliposomes. Suitability of oil red O as a liposome marker was confirmed by stability studies of the incorporated dye and automated fluorescence cell counting. The C.C stretching region with a prominent wide band centered at 1080 cm.1 indicative of larger gauche conformer content typical for the lecithin-cholesterol nanoliposomes and the strong maximum at 980 cm.1 associated with O.C.C.N+ stretching vibrations of the liposome polar head groups are important for studying label-free nanoliposome cell internalization

Digital light processing 3D printing of Hydrochlorothiazide with modified release

Additive manufacturing also known as 3D printing gains more attention in scientific research due to its great advantages in simple and fast producing custom-designed products. 3D models created with computer-aided design (CAD) are presented to the printers and with different techniques, printing layer-by-layer desired products are made. Most used techniques in additive manufacturing are fused deposition modeling (FDM), material and ink jetting, sintering and vat polymerization techniques. Stereolithography (SLA) and digital light processing (DLP) are the most frequently used techniques in vat polymerization due to their advantages. In DLP technique, a digital micromirror is used for gradually exposing and solidifying a layer of liquid photopolymer solution following a layer-by-layer mechanism (Adamov et al., 2022; Zhu et al., 2020). Nowadays additive manufacturing finds its place in medicine by producing medical devices, implants, prostheses and medical equipment. 3D printing has enormous potential in personalized medicine as a result of different possibilities in production of dosage forms with desired shapes that contain one or more active compounds that can have different release profiles. 3D printing helps in overcoming the problem with permeability and solubility of some drugs and enables using drugs from different BCS classes.14th Central European Symposium on Pharmaceutical Technology, 28th - 30th September, Ohrid, N. Macedonia, 202