Evaluation of the Effect of Formulation Composition and Physicochemical Properties of Omeprazole and Bisoprolol Hemifumarate on Electrospun Nanofibers Characteristics

The present work comprises the formulation and evaluation of losartan potassium with a view to developing and preparing a losartan potassium releasing system for transdermal applications. The aim of the study was to prepare the transdermal patch of drug using different blends of polymers. Transdermal patches of losartan potassium were prepared using ethyl cellulose (EC): polyvinyl pyrrolidone (PVP), Eudragit RL-100: Eudragit RS-100 and polyvinyl alcohol (PVA): polyvinyl pyrrolidone (PVP) using different ratios by the solvent casting technique. Physicochemical parameters like flexibility, thickness, smoothness, moisture content, hardness, and tensile strength were studied. The in vitro permeation study was carried out using a modified Keshery diffusion cell, and the formulation followed the Higuchi diffusion mechanism. The blood pressure lowering response of all formulations was studied using hypertension-induced rats by the chronic renal hypertension method. The formulation containing Eudragit RL-100: Eudragit RS-100 as polymers showed satisfactory drug release pattern (hydrophobic polymers) compared to combination of hydrophobic and hydrophilic polymers (EC: PVP) and PVA: PVP (hydrophilic polymers). The amount of drug release from formulations containing hydrophilic polymers and combination of both hydrophobic and hydrophilic polymers were found to be less in comparison to the patches of hydrophobic polymers. The aim of the present study was to prepare and evaluate the transdermal patch of drug using different polymers such as hydrophobic, combination of hydrophobic: hydrophilic, and hydrophilic. Losartan potassium (hydrophilic) is the antihypertensive drug used for lowering increased blood pressure. Transdermal patches of losartan potassium were prepared using different ratios of polymers by the solvent casting technique. The prepared patches were evaluated for their flexibility, thickness, smoothness, moisture content, hardness, and tensile strength. The in vitro permeation study was carried out using a diffusion cell. The blood lowering response of all formulations was studied using hypertension-induced rats. The formulation containing hydrophobic polymers showed a satisfactory drug release pattern compared to the combination of hydrophobic: hydrophilic polymers and the hydrophilic polymers. Hence, the present study reveals that formulation of hydrophilic drug (losartan potassium) withhydrophobic polymers exhibit good release properties as compared to that of hydrophilic polymers and combination of both hydrophobic and hydrophilic polymers.

Engineering polymer blend microparticles: An investigation into the influence of polymer blend distribution and interaction

Sustained-release matrix tablets based on Eudragit RL and RS were manufactured by injection moulding. The influence of process temperature; matrix composition; drug load, plasticizer level; and salt form of metoprolol: tartrate (MPT), fumarate (MPF) and succinate (MPS) on ease of processing and drug release were evaluated. Formulations composed of 70/30% Eudragit RL/MPT showed the fastest drug release, substituting part of Eudragit RL by RS resulted in slower drug release, all following first-order release kinetics. Drug load only affected drug release of matrices composed of Eudragit RS: a higher MPT concentration yielded faster release rates. Adding triethyl citrate enhanced the processability, but was detrimental to long-term stability. The process temperature and plasticizer level had no effect on drug release, whereas metoprolol salt form significantly influenced release properties. The moulded tablets had a low porosity and a smooth surface morphology. A plasticizing effect of MPT, MPS and MPF on Eudragit RS and Eudragit RL was observed via DSC and DMA. Solubility parameter assessment, thermal analysis and X-ray diffraction demonstrated the formation of a solid solution immediately after production, in which H-bonds were formed between metoprolol and Eudragit as evidenced by near-infrared spectroscopy. However, high drug loadings of MPS and MPF showed a tendency to recrystallise during storage. The in vivo performance of injection-moulded tablets was strongly dependent upon drug loading.

Effervescent multiple-unit floating drug delivery systems (muFDDSs) consisting of drug (lorsartan)- and effervescent (sodium bicarbonate)-containing pellets were characterized in this study. The mechanical properties (stress and strain at rupture, Young’s modulus, and toughness) of these plasticized polymeric films of acrylic (Eudragit RS, RL, and NE) and cellulosic materials (ethyl cellulose (EC), and Surelease) were examined by a dynamic mechanical analyzer. Results demonstrated that polymeric films prepared from Surelease and EC were brittle with less elongation compared to acrylic films. Eudragit NE films were very flexible in both the dry and wet states. Because plasticizer leached from polymeric films during exposure to the aqueous medium, plasticization of wet Eudragit RS and RL films with 15% triethyl citrate (TEC) or diethyl phthalate (DEP) resulted in less elongation. DEP might be the plasticizer of choice among the plasticizers examined in this study for Eudragit RL to provide muFDDSs with a short time for all pellets to float (TPF) and a longer period of floating. Eudragit RL and RS at a 1∶1 ratio plasticized with 15% DEP were optimally selected as the coating membrane for the floating system. Although the release of losartan from the pellets was still too fast as a result of losartan being freely soluble in water, muFDDSs coated with Eudragit RL and RS at a 1∶1 ratio might have potential use for the sustained release of water-insoluble or the un-ionized form of drugs from gastroretentive drug delivery systems.

Crystal growth formation in melt extrudates

The influence of surfactants on drug release from acrylic matrices

Antimicrobial resistance arises from treatment non-adherence and ineffective delivery systems. Optimal wound dressings combine localized drug release, exudate management, and bacterial encapsulation through hydrogel-forming nanofibers for enhanced therapy. In this work, polylactic acid (PLA) and polyvinylpyrrolidone (PVP) fibers loaded with chlorhexidine (CHX) were developed using Solution Blow Spinning (SBS), a scalable electrospinning alternative that enables in situ deposition. Molecular interactions between CHX and polymers in solution (by UV-Vis and fluorescence spectroscopy) and in solid state (by FTIR, XRD and thermal analysis) were studied. The morphology of the polymeric fibers was determined by optical microscopy, showing that PVP fibers are thinner (1625 nm) and more uniform than those of PLA (2237 nm). Finally, drug release from single-polymer fibers discs, overlapping fibers discs (PLA/PVP/PLA and PVP/PLA/PVP), and solid dispersions was determined by UV-Vis spectrometry. PVP-based fibers exhibited faster CHX release due to their hydrophilic nature, while PLA fibers proved sustained release, attributed to their hydrophobic matrix. This study highlights the potential of PLA/PVP-CHX fibers made from SBS as advanced wound dressings, combining biocompatibility and personalized drug delivery, offering a promising platform for localized and controlled antibiotic delivery.

Sustained release cephalexin tablets were prepared by using different polymers like HPMC K4M, HPMC K15M, HPMC K100M, HPMC K 100LV, Ethyl cellulose, Carbopol 971P, Carbopol 974P, Eudragit RS100, Eudragit RL100 and Eudragit L100. The tablets were prepared by wet granulation technique and were evaluated for different parameters such as thickness, hardness, weight uniformity, content uniformity, friability, in-vitro drug release, drug release mechanism study and stability studies. The results of the studies indicate that the polymers used have significant release-retarding effect on the formulation. The dissolution profile comparison of the prepared batches and market preparation (Nufex CR Tablet) was done by similarity and difference factor determination. The formulation K4 (5.8% HPMC K100M, 1.0% ethyl cellulose) with a similarity factor of 68.28 was found to be nearest to the marketed formulation. Formulation K4 shows first order drug release and the mechanism of drug release was found to be anomalous. The results of the accelerated stability study of best formulation K4 for two months revealed no significant changes in formulation. It is concluded that carbopol, eudragit and HPMC were found to be suitable as bases for preparing tablet matrices containing Cephalexin but only carbopol 971and HPMC K4M were able to produce release profile similar to that of marketed preparation. Keyword: Cephalexin, Dissolution profile, Ethyl cellulose, Stability study, Sustained release

Objective Eudragits are widely used polymers in the production of oral sustained release dosage forms. The application of these polymers in the production of inert insoluble matrices has been investigated. However the effect of particle size, compaction force and presence of Aerosil 200 as a glidant on the properties of Eudragit RS and RL matrices prepared by direct compression of their physical mixtures with drug have not been fully investigated. This study was performed in order to investigate the effect of above mentioned factors on physicomechanical and release properties of propranolol hydrochloride and Eudragit RS or RL matrices. Materials and Methods Polymers were separated to different size fractions using series of sieves. Matrices were prepared in 1:3 ratio by direct compression of physical mixture of drug and polymer. To study the effect of Aerosil 200, matrices were prepared from different size fractions containing 1%w/w Aerosil 200. To investigate the effect of compaction force, the 125-177µm size fraction of polymer was chosen and compression carried out at 5, 10, 15, 20 and 30 kN compaction force. Matrices were characterized for their hardness and dissolution. Results The results showed that due to decrease in tablet hardness the release rate increased with increase in polymer particle size. Drug release rates were almost the same for both polymers at similar particle size range. The same trend was also observed for matrices containing Aerosil 200. Addition of Aerosil 200 decreased the rate of drug release from all matrices except those prepared from 250-350 µm size fraction. This was attributed to increase in the tablet hardness. Increase in compaction force from 5kN to 20kN increased the tablet hardness and consequently decreased the release rate, however, further increase in compaction force from 20 to 30 kN did not significantly affect the release rates of drug. Conclusion Polymer particle size, presence of Aerosil and compaction force are important factors affecting drug release from Eudragit RS or RL matrices. Eudragit RS and RL polymers alone are not suitable for preparation of sustained release matrices containing water soluble drugs.

Relationship of Film Properties to Drug Release from Monolithic Films Containing Adjuvants

Sustained release solid dispersions of indomethacin with Eudragit RS and RL

Purpose: To employ response surface methodology (RSM) for statistical optimization of formulation factors in the preparation of celecoxib-loaded microspheres.Methods: Celecoxib microspheres were prepared by solvent evaporation method. Biodegradable/biocompatible polymers, Eudragit L-100 and polyvinyl pyrrolidone, were used in the encapsulation procedure. A central composite design employing Stat-Ease design Expert®, version 7.0.3 having a unit value of á was used according to reference protocols to assess the influence of two independent variables (i.e., the concentration of the two polymers used) on four dependent variables (i.e., recovery, encapsulation efficiency and % drug released). The polymers used were Eudragit-L100 (X1) and polyvinyl pyrrolidone (X2). The microspheres were characterized for size, shape, recovery (%), entrapment efficiency and drug release.Results: The recovered total weight of microspheres ranged between 49.4 ± 3.1 and 91.1 ± 4.8 %, and it decreased with increase in the concentration of PVP. Entrapment efficiency was in the range of 54.1 ±2.9 to 95.6 ± 3.7 %, and was also dependent on polymer concentration. The release of celecoxib increased with decrease in Eudragit L-100 concentration and increase in PVP concentration. Higuchi model was the best-fit drug release from all the formulations. Korsemeyer-Peppas release exponent (n) indicates that drug release pattern was non-Fickian diffusion.Conclusion: Using RSM, it is possible to optimize the drug release properties of celecoxib-loaded microspheres. A celecoxib-loaded microsphere formulation with optimum recovery, entrapment efficiency and release behavior was proposed.Keywords: Celecoxib, Eudragit L-100, Polyvinyl pyrrolidone, Response surface methodology, Microspheres.

The present work investigated the release of Flurbiprofen (FLU) from Eudragit RS100 (RS) and Eudragit RL100 (RL) nanosuspensions to a biological model membrane consisting of Dimyristoylphosphatidylcholine (DMPC) multilamellar vesicles (MLV). This release was compared with those observed from solid drug particles as well as with dialysis experiments. Nanosuspensions were prepared by a modification of Quasi-Emulsion Solvent Diffusion technique. Drug release was monitored by the Differential Scanning Calorimetry (DSC). FLU dispersed in MLV affects the transition temperature (T(m)) of DMPC liposomes, causing a shift towards lower values. The temperature shift is modulated by the drug fraction present in the aqueous lipid bilayer suspension. DSC was also performed, after increasing incubation periods at 37 degrees C, on suspensions of blank liposomes added to fixed amounts of unloaded and FLU-loaded nanosuspensions, as well as to powdered free drug. T(m) shifts, caused by the drug released from the polymeric system or by free-drug dissolution during incubation cycles, were compared with those caused by free drug increasing molar fractions dispersed directly in the membrane during their preparation. These results were compared with the drug release and were followed by a classical dialysis technique. Comparing the suitability of the 2 different techniques in order to follow the drug release as well as the differences between the 2 RL and RS polymer systems, it is possible to confirm the efficacy of DSC in studying the release from polymeric nanoparticulate systems compared with the "classical" release test by dialysis. The different rate of kinetic release could be due to void liposomes, which represent a better uptaking system than aqueous solution in dialysis experiments.

Background: Different methods have been studied for targeting drugs to the colon, such as pH-based, time dependent and bacterially degradable systems. However, due to variations in physiological conditions of patients, one system alone could not be completely reliable on colonic drug delivery. Objectives: The aim of this study was preparation and evaluation of a novel colon-specific drug delivery system for 5-ASA (mesalazine) pellets using pectin as a microbially degradable polymeric carrier and Eudragit RS (ERS) and Eudragit RL (ERL) as time-dependent polymers. Materials and Methods: Formulations were constructed based on a multilevel full factorial design. Pellets were prepared via extrusion - spheronization and evaluated for physicochemical properties, image analysis, SEM, FT-IR, DSC and in vitro drug release studies in the simulated gastric fluid with pH = 1.2 (SGF), simulated intestinal fluid with pH = 6.8 (SIF) and simulated colonic fluid with pH = 6.8 in presence of pectinolytic enzyme (SCF). Results: It was shown that in the presence of pectin, formulations without ERL had a relative resistance to drug release in SGF. Pellets containing pectin and the least amount of ERS had the highest burst release effect in SCF. On the other hand, increasing in amount of ERS in the formulations caused a sustained drug release. Presence of pectin in formulations containing ERS and ERL caused sensitivity of formulations to pectinolytic enzyme which can suitable for a colon specific drug delivery system. Conclusions: It was shown that combination of pectin and eudragits can relatively control drug release in the upper GI. On the other hand, pectin degraded in the presence of pectinase and formulations were susceptible to the colonic media.

BackgroundDifferent methods have been studied for targeting drugs to the colon, such as pH-based, time dependent and bacterially degradable systems. However, due to variations in physiological conditions of patients, one system alone could not be completely reliable on colonic drug delivery.ObjectivesThe aim of this study was preparation and evaluation of a novel colon-specific drug delivery system for 5-ASA (mesalazine) pellets using pectin as a microbially degradable polymeric carrier and Eudragit RS (ERS) and Eudragit RL (ERL) as time-dependent polymers.Materials and MethodsFormulations were constructed based on a multilevel full factorial design. Pellets were prepared via extrusion - spheronization and evaluated for physicochemical properties, image analysis, SEM, FT-IR, DSC and in vitro drug release studies in the simulated gastric fluid with pH = 1.2 (SGF), simulated intestinal fluid with pH = 6.8 (SIF) and simulated colonic fluid with pH = 6.8 in presence of pectinolytic enzyme (SCF).ResultsIt was shown that in the presence of pectin, formulations without ERL had a relative resistance to drug release in SGF. Pellets containing pectin and the least amount of ERS had the highest burst release effect in SCF. On the other hand, increasing in amount of ERS in the formulations caused a sustained drug release. Presence of pectin in formulations containing ERS and ERL caused sensitivity of formulations to pectinolytic enzyme which can suitable for a colon specific drug delivery system.ConclusionsIt was shown that combination of pectin and eudragits can relatively control drug release in the upper GI. On the other hand, pectin degraded in the presence of pectinase and formulations were susceptible to the colonic media.