Magnesium Aluminometasilicate Research Articles

The Solution Improvement of Quercetin Using Spontaneous Emulsification Systems

Quercetin has been used for health promotion for instance anti-bacterial, anti-inflammatory, anti-coagulative, antineoplastic and antioxidant. The poorly water-soluble quercetin has been a significant problem of bioavailability for oral administration. The objective of this study was to improve the quercetin solubility by spontaneous emulsion formulation (SEF). SEF was fabricated by dissolved quercetin in mixture of polyoxyl 35 castor oil, diethylene glycol monoethy ether, caprylic/capric glyceride. The solid-SEF was obtained by incorporation with solid carrier adsorbent (magnesium aluminometasilicate). The photon correlation spectroscopy was used to determine the emulsion size of diluted SEF and solid-SEF. The power X-ray diffraction and differential scanning calorimetry were also employed to elucidate the powder of solid-SEF compared with unmodified quercetin. The dissolution profiled at 120 min of unmodified quercetin, SEF and solid-SEF was about 2%, 77% and 89%, respectively.

Development of New Formula Microcapsules from Nutmeg Essential Oil Using Sucrose Esters and Magnesium Aluminometasilicate.

Essential oils are volatile liquids which evaporate and lose their pharmacological effect when exposed to the environment. The aim of this study is to protect nutmeg essential oil from environmental factors by encapsulation (shell material, sodium alginate) and determine the influence of crosslinker concentration (2%, 5% calcium chloride), different emulsifiers (polysorbate 80, sucrose esters), and magnesium aluminometasilicate on microcapsule physical parameters, encapsulation efficiency (EE), swelling index (SI), and other parameters. Nutmeg essential oil (NEO)-loaded calcium alginate microcapsules were prepared by extrusion. The swelling test was performed with and without enzymes in simulated gastric, intestinal, and gastrointestinal media. This study shows that the crosslinker concentration has a significant influence on EE, with 2% calcium chloride solution being more effective than 5%, and capsules being softer with 2% crosslinker solution. Using sucrose esters, EE is higher when polysorbate 80 is used. The swelling index is nearly three times higher in an intestinal medium without enzymes than in the medium with pancreatin. Microcapsule physical parameters depend on the excipients: the hardest capsules were obtained with the biggest amount of sodium alginate; the largest with magnesium aluminometasilicate. Sucrose esters and magnesium aluminometasilicate are new materials used in extrusion.

The Essential Oil and Hydrolats from Myristica fragrans Seeds with Magnesium Aluminometasilicate as Excipient: Antioxidant, Antibacterial, and Anti-inflammatory Activity.

Nutmeg (Myristica fragrans) essential oil has antimicrobial, antiseptic, antiparasitic, anti-inflammatory, and antioxidant properties. We have recently demonstrated that hydrodistillation of nutmeg essential oil by applying magnesium aluminometasilicate as an excipient significantly increases both the content and amount of bioactive substances in the oil and hydrolats. In this study, we aimed to compare the antioxidant, antimicrobial, and anti-inflammatory activity of hydrolats and essential oil obtained by hydrodistillation in the presence and absence of magnesium aluminometasilicate as an excipient. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method revealed that magnesium aluminometasilicate did not significantly improved antioxidant activity of both essential oil and hydrolat. Antibacterial efficiency was evaluated by monitoring growth of 15 bacterial strains treated by a range of dilutions of the essential oil and the hydrolats. Essential oil with an excipient completely inhibited the growth of E. faecalis, S. mutans (referent), and P. multocida, whereas the pure oil was only efficient against the latter strain. Finally, the anti-inflammatory properties of the substances were assessed in a fibroblast cell culture treated with viral dsRNR mimetic Poly I:C. The essential oil with an excipient protected cells against Poly I:C-induced necrosis more efficiently compared to pure essential oil. Also, both the oil and the hydrolats with aluminometasilicate were more efficient in preventing IL-6 release in the presence of Poly I:C. Our results show that the use of magnesium aluminometasilicate as an excipient might change and in some cases improve the biological activities of nutmeg essential oil and hydrolats.

Unique coated neusilin pellets with a more distinct and fast visual detection of nerve agents and other cholinesterase inhibitors

Pellets with an immobilized enzyme (acetyl- or butyrylcholinesterase) are the up-to-date type of carriers used for the detection of nerve agents (soman, sarin, tabun, VX, Novichok) and other cholinesterase inhibitors such as organophosphate and carbamate insecticides (parathion, malathion). They are used in the glass detection tubes as a layer containing the enzyme together with the second layer, which contains a colorimetric reagent and substrate. The detection method is based on the visually or spectrophotometrically observable Ellman's reaction, which develops a yellow color in the absence of the cholinesterase inhibitor; otherwise, the detector preserves its original color (preferably white). This reaction occurs very fast and has a high sensitivity to nerve agents but it suffers from an indistinctive color transition from white to yellow. In the presented study, a new approach with the use of the synergic effect of magnesium aluminometasilicate with a high surface area marketed as Neusilin®US2 and a protective semipermeable Eudragit® RL layer was utilized. The prepared pellets have been evaluated for their properties such as the activity of the enzyme, intensity of the developed yellow color, sensitivity to cholinesterase inhibitor physostigmine, which acts as a nerve agent simulant, and physical parameters such as hardness, pycnometric density and sphericity. After the initial evaluation, all samples underwent a stability test under three different storage conditions for 24 months during which they were evaluated at given time points (0, 3, 6, 12 and 24 months). It was found that the prepared samples achieved a much higher intensity of developed yellow color than in the published studies while maintaining similar or better sensitivity, speed of detection and suitable physico-chemical properties.

Development of Alginate- Neusilin US2 (Magnesium alumino-metasilicate) micro-composite hydrogel beads for oral sustained release of cilnidipine: a statistical optimization

ABSTRACTIn presented work Alginate-Neusilin US2 micro-composite beads (MCBs) were formulated and optimized for oral delivery of cilnidipine (CIL). Optimized formulation of CIL loaded MCB (BA-O) exhibits particle size (1.55 ± 0.05mm), entrapment efficiency (82.35 ± 1.5%), and drug release after 12h (69.27 ± 2.2%). In vitro drug release indicates sustained drug release behavior following anomalous diffusion mechanism. The desirability function helps in formulating a new formulation with desired values of response. Furthermore, multiple linear regression analysis (MLRA) helps to predict influence of independent variables on dependent variables. The optimized MCB can be sorted as novel approach for sustaining CIL release profile to get maximum health benefits.

THE THE METHOD OF RANDOM BALANCE FOR STUDYING THE INFLUENCE OF EXCIPIENTSʼ QUANTITIES ON TECHNOLOGICAL PARAMETERS OF METFORMIN ORODISPERSIBLE TABLETS

Objective: The present investigation was undertaken with an objective of analyzing the influence of excipientsʼ amount on the technological parameters of metformin orodispersible tablets using the method of random balance.
 Methods: The tablets were prepared by using direct compression method. The formulations were designed according to the method of random balance. The technological parameters of metformin orodispersible tablets have been studied as a function of quantitative factors: crospovidone (Polyplasdone XL-10®), magnesium aluminometasilicate (Neusilin US2®), microcrystalline cellulose (MCC Sanaq® burst), lactose monohydrate, magnesium stearate (Tablube® MgSt micronized vegetable) and talc. 
 Results: The flowability results were ranging from excellent to good according to the quantities of Neusilin US2® and Polyplasdone XL-10® crospovidone, which used. Results of bulk density and tapped density of the powder mixtures for pressing depended from the quantities of Neusilin US2® and talc. The obtained tablets had uniform weight from 0.93 to 2.30 %. The increase in the amount of Polyplasdone XL-10® crospovidone and the decrease in the amount of talk improved the uniformity of tablets’ weights. All of the prepared tablets showed acceptable hardness and friability which were improved with decrease in the amount of MCC Sanaq®burst and increase in the amount of Neusilin US2®. The rapid disintegration and wetting time for all formulations of tablets were obtained by using the Polyplasdone XL-10® crospovidone and MCC Sanaq®burst.
 Conclusion: Oral disintegrating tablets of metformin were successfully prepared by direct compression method. The random balance method enabled us to identify the most significant quantitative factors and stabilize them at optimal values.

GC-MS Analysis of the Composition of the Extracts and Essential Oil from Myristica fragrans Seeds Using Magnesium Aluminometasilicate as Excipient.

Myristica fragrans (f. Myristicaceae) seeds are better known as a spice, but their chemical compounds may have a pharmacological effect. The yield of their composition of extracts and essential oils differs due to different methodologies. The aim of this study was to evaluate an excipient material—magnesium aluminometasilicate—and to determine its influence on the qualitative composition of nutmeg extracts and essential oils. Furthermore, we wanted to compare the yield of essential oil. The extracts were prepared by maceration (M) and ultrasound bath-assisted extraction (UAE), and the essential oil—by hydrodistillation (HD). Conventional methods (UAE, HD) were modified with magnesium aluminometasilicate. The samples were analyzed by gas chromatography-mass spectrometry (GC-MS) method. From 16 to 19 chemical compounds were obtained using UAE with magnesium aluminometasilicate, while only 8 to 13 compounds were obtained using UAE without an excipient. Using our conditions and plant material, for the first time eight new chemical compounds in nutmeg essential oil were identified. Two of these compounds (γ-amorphene and cis-α-bergamotene) were obtained with the use of excipient, the other six (β-copaene, bergamotene, citronellyl decanoate, cubebol, cubenene, orthodene) by conventional hydrodistillation. Magnesium aluminometasilicate significantly increased the quantity of sabinene (from 6.53% to 61.42%) and limonene (from 0% to 5.62%) in essential oil. The yield of the essential oil from nutmeg seeds was significantly higher using magnesium aluminometasilicate; it increased from 5.25 ± 0.04% to 10.43 ± 0.09%.

A spray dried Nelfinavir Mesylate particles for enhanced oral bioavailability: Systematic formulation optimization and in-vivo performance.

The current endeavor was aimed to fabricate spray dried Nelfinavir Mesylate particles (SDNPs) that upon reconstitution with body fluids releases amorphous Nelfinavir Mesylate with enhanced oral bioavailability. For this purpose, feed mixture was prepared containing solubilized NFM, solid substrate and solvent system. The NFM was solubilized in a mixture of Maisine 35-1 (200 mg), Tween80 (500 mg) and Transcutol HP (300 mg). Three different solid substrates with high specific surface area were used: Neusilin® UFL2, (magnesium aluminometasilicate), Aerosil 200® (colloidal silica) and Syloid 244 FP® (porous silicon dioxide). Central composite design-response surface methodology (CCD-RSM) with three-factor (two numeric and one categorical) at three-level was used to select the appropriate solid substrate and to develop optimized SDNPs. The solid characterization by scanning electron microscopy, differential scanning calorimetry and powder X-ray diffraction studies indicated the absence of crystalline NFM in the formulations. The drug distribution analysis using raman spectroscopy suggested uniform distribution of amorphous NFM in optimized SDNPs-1 formulation. The transmission electron microscopy revealed the spherical structure of reconstituted SDNPs that releases amorphous NFM with globules size less than 110 nm. The solid substrate had significant and positive effect in drug dissolution; the mean dissolution time of NFM loaded in SDNPs was considerably improved. The bioavailability study resulted in enhanced magnitude of Cmax and AUC for SDNPs. The tissue distribution studies exhibited significantly higher brain and lymph nodes distribution as compared to putative form. Overall, the results pointed towards the overwhelming response of the SDNPs to be used for HIV treatment.

Self-microemulsifying tablets prepared by direct compression for improved resveratrol delivery

The purpose of this study was to develop self-microemulsifying (SME-) tablets to improve resveratrol solubility whilst delivering resveratrol in a preferred tablet dosage form. Resveratrol was dissolved in liquid self-microemulsifying drug delivery system (SMEDDS) (10% w/w) and solidified through adsorption on several different solid carriers. Two ranges of synthetic amorphous silica (Sylysia® 290, 350, 470, 580; Syloid® 244FP, AL-1FP) as well as granulated magnesium aluminometasilicate (Neusilin® US2) were screened for their SMEDDS adsorbent capacity. The most efficient carrier from every range was chosen for further SME-tablet development. To counteract the high ratio of liquid in SME-tablets, additional dry binders (microcrystalline cellulose, copovidone) were added to the tableting mixture, as well as superdisintegrant (croscarmellose sodium) and lubricant (magnesium stearate). Finally, approx. 600 mg tablets were directly pressed using 12 mm flat face punch, containing 41.75% SMEDDS. Overall, all tablets exhibited sufficient hardness (>50 N), although it was negatively affected by higher compression force. Tablets with Neusilin® US2 proved to have highest hardness, as granulated structure of Neusilin® US2 provided best compaction properties needed for successful direct compression of tablets. All prepared SME tablet formulations disintegrated in under 10 min and formed microemulsions (droplet size < 100 nm) upon dilution with water, with Neusilin® US2 tablets exhibiting the lowest droplet size (<30 nm). While conventional dissolution test indicated incomplete resveratrol release from solid carriers in both pH 1.2 and 6.8 media, no difference fatty acid amount titrated during fasted state in vitro lipolysis between liquid and solid SMEDDS was observed. Moreover, accelerated stability tests confirmed over 90% of trans-resveratrol remained in solid SMEDDS following 90 days at 40 °C, with no crystallization of resveratrol observed during that time. To sum up, through adsorption on solid carriers, in particular Neusilin® US2, SMEDDS was successfully transformed into a directly compressible mixture and tableted without the loss of its self-microemulsifying ability.

Chemico-calorimetric analysis of amorphous granules manufactured via continuous granulation process

The current study explores the first case of the implementation of solution calorimetry (SolCal) in order to determine the amorphous content of crystalline benzoyl-methoxy-methylindol-acetic acid (BMA)—a model poorly soluble drug, in the amorphous granules prepared via single-step continuous twin-screw dry granulations (TSG). Amorphous magnesium aluminometasilicate (Neusilin®) (US2) was used as a novel inorganic carrier via a TwinLab 10 mm twin-screw extruder. The BMA/US2 blends were processed at 180 °C and varying drug: carrier ratios of 1:4, 1:2.5 and 1:1 (w/w). Physico-chemical characterisation conducted via SEM, DSC and XRPD showed amorphous state of the drug in all granulated formulations. Reverse optical microscopy revealed a meso-porous structure of US2 in which the drug particles are adsorbed and/or entrapped within the porous network of the carrier. This phenomenon can be the underlying reason for the increase of the amorphous content in the extruded granules. Solution calorimetry (SolCal) study revealed amorphous content of the drug in all formulations quite precisely, whereas the dynamic vapour sorption (DVS) analysis complemented the results from SolCal. Furthermore, an attempt has been made for the first time to interrelate the findings from the SolCal to that of the release of the drug from the amorphous granules. It can be concluded that SolCal can be used as a novel technique to precisely quantify and interrelate the amorphous content to its physico-chemical performances such as drug release from the granulated formulations processed via TSG.

Development of sustained-release microparticles containing tamsulosin HCl for orally disintegrating tablet using melt-adsorption method

In this study, using the melt-adsorption method, we developed sustained-release microparticles containing the potent drug, tamsulosin HCl, for use as orally disintegrating tablets. A high-speed kneading granulator was used, enabling temperature modulation and uniform material distribution. A lipid and ethylcellulose suspension (Surelease®) was applied to retard drug release, and magnesium aluminometasilicate (Neusilin®) was used as adsorbent. Among various lipid candidates for melt-adsorption, beeswax and glyceryl behenate were selected due to their high mechanical strength. Hot stage microscopy and powder X-ray diffraction analysis results showed compatibility between tamsulosin HCl and both lipids. Characteristic adsorption behavior was observed depending on the physicochemical properties of each composition. Especially, the specific surface area of Neusilin® decreased with increasing amounts of Surelease®, attributed to the pore-covering effect of Surelease®, which significantly increased the size of the microparticles after the lipid adsorption. For a Surelease®-to-beeswax ratio 1:50, both the desired particle size distribution and low burst release were achieved. Furthermore, the orally disintegrating tablet containing optimized microparticles had acceptable tablet hardness and rapid disintegration. Herein, the feasibility of melt-adsorption for the preparation of sustained-release microparticles was well demonstrated. With its convenience and efficiency, the proposed method is a promising alternative to conventional methods, which are relatively difficult and time consuming.

Investigation of Dissolution Behavior HPMC/Eudragit®/Magnesium Aluminometasilicate Oral Matrices Based on NMR Solid-State Spectroscopy and Dynamic Characteristics of Gel Layer

Burst drug release is often considered a negative phenomenon resulting in unexpected toxicity or tissue irritation. Optimal release of a highly soluble active pharmaceutical ingredient (API) from hypromellose (HPMC) matrices is technologically impossible; therefore, a combination of polymers is required for burst effect reduction. Promising variant could be seen in combination of HPMC and insoluble Eudragits® as water dispersions. These can be applied only on API/insoluble filler mixture as over-wetting prevention. The main hurdle is a limited water absorption capacity (WAC) of filler. Therefore, the object of this study was to investigate the dissolution behavior of levetiracetam from HPMC/Eudragit®NE matrices using magnesium aluminometasilicate (Neusilin® US2) as filler with excellent WAC. Part of this study was also to assess influence of thermal treatment on quality parameters of matrices. The use of Neusilin® allowed the application of Eudragit® dispersion to API/Neusilin® mixture in one step during high-shear wet granulation. HPMC was added extragranularly. Obtained matrices were investigated for qualitative characteristics, NMR solid-state spectroscopy (ssNMR), gel layer dynamic parameters, SEM, and principal component analysis (PCA). Decrease in burst effect (max. of 33.6%) and dissolution rate, increase in fitting to zero-order kinetics, and paradoxical reduction in gel layer thickness were observed with rising Eudragit® NE concentration. The explanation was done by ssNMR, which clearly showed a significant reduction of the API particle size (150-500nm) in granules as effect of surfactant present in dispersion in dependence on Eudragit®NE amount. This change in API particle size resulted in a significantly larger interface between these two entities. Based on ANOVA and PCA, thermal treatment was not revealed as a useful procedure for this system.

The development of a butyrylcholinesterase porous pellet for innovative detection of cholinesterase inhibitors

The aim of the presented research was the preparation of an innovative carrier with significantly improved properties for the fast and sensitive detection of cholinesterase inhibitors such as nerve agents. This innovative carrier was in the form of spherical pellets containing different amounts of Neusilin. Neusilin is a synthetic and amorphous form of magnesium aluminometasilicate with a high specific surface area, and the immobilized enzyme butyrylcholinesterase with an activity of 50nkat·g−1. Pellets were prepared by the extrusion-spheronization method and dried in a hot air oven under two conditions – at 30°C for 72h and at 60°C for 24h. Dried pellets were consequently impregnated with a solution containing butyrylcholinesterase. Impregnated pellets were evaluated for their quality parameters, enzymatic activity and inhibition. Activity and inhibition were tested according to the standard Ellman's method. It was observed that the addition of Neusilin significantly increased the hardness, intraparticular porosity, sphericity and activity of the carriers as well as intensity of the color transition. Therefore it is shown that these carriers have unquestionable advantages over common carriers of their kind. Drying temperatures have been shown to have no effect on properties of pellets except for a change in their size. Results were confirmed by statistical evaluation using ANOVA and PCA.

Development of novel amisulpride-loaded solid self-nanoemulsifying tablets: preparation and pharmacokinetic evaluation in rabbits

Objective: The current investigation is focused on the formulation and in vivo evaluation of optimized solid self-nanoemulsifying drug delivery systems (S-SNEDDS) of amisulpride (AMS) for improving its oral dissolution and bioavailability.Methods: Liquid SNEDDS (L-SNEDDS) composed of Capryol™ 90 (oil), Cremophor® RH40 (surfactant), and Transcutol® HP (co-surfactant) were transformed to solid systems via physical adsorption onto magnesium aluminometasilicate (Neusilin US2). Micromeretic studies and solid-state characterization of formulated S-SNEDDS were carried out, followed by tableting, tablet evaluation, and pharmacokinetic studies in rabbits.Results: Micromeretic properties and solid-state characterization proved satisfactory flow properties with AMS present in a completely amorphous state. Formulated self-nanoemulsifying tablets revealed significant improvement in AMS dissolution compared with either directly compressed or commercial AMS tablets. In vivo pharmacokinetic study in rabbits emphasized significant improvements in tmax, AUC(0–12), and AUC(0–∞) at p < .05 with 1.26-folds improvement in relative bioavailability from the optimized self-nanoemulsifying tablets compared with the commercial product.Conclusions: S-SNEDDS can be a very useful approach for providing patient acceptable dosage forms with improved oral dissolution and biovailability.

Increased dissolution rates of tranilast solid dispersions extruded with inorganic excipients

The purpose of this study was to evaluate the performance of Neusilin® (NEU) a synthetic magnesium aluminometasilicate as an inorganic drug carrier co-processed with the hydrophilic surfactants Labrasol and Labrafil to develop Tranilast (TLT)-based solid dispersions using continuous melt extrusion (HME) processing. Twin-screw extrusion was optimized to develop various TLT/excipient/surfactant formulations followed by continuous capsule filling in the absence of any downstream equipment. Physicochemical characterization showed the existence of TLT in partially crystalline state in the porous network of inorganic NEU for all extruded formulations. Furthermore, in-line NIR studies revealed a possible intermolecular H-bonding formation between the drug and the carrier resulting in the increase of TLT dissolution rates. The capsules containing TLT-extruded solid dispersions showed enhanced dissolution rates and compared with the marketed Rizaben® product.

Isolation and Physical Property Optimization of an Amorphous Drug Substance Utilizing a High Surface Area Magnesium Aluminometasilicate (Neusilin® US2)

Control and optimization of the physical properties of a drug substance (DS) are critical to the development of robust drug product manufacturing processes and performance. A lack of isolatable, for example, crystalline, DS solid forms can present challenges to achieving this control. In this study, an isolation scheme for an amorphous DS was developed and integrated into the synthetic route producing DS with optimized properties. An inert absorbent excipient (Neusilin® US2) was used to isolate the DS via a novel antisolvent scheme as the final step of the route. Isolation was executed at kilogram scale utilizing conventional equipment. The resulting 50 wt% DS:Neusilin complex had improved physical stability and exceptional micromeritic and tableting properties. Improved dissolution was observed and attributed to enhanced dispersion and increased surface area. Characterization data suggest a high degree of penetration of the DS into the Neusilin, with DS occupying 70% of mesopore and 12% of macropore volume. This approach has application in the isolation and particle engineering of difficult to isolate DS without additional unit operation, such as spray drying, and has the potential for a high degree of optimization and control of physical properties over the course of DS development.

Development and optimization of ketoconazole oral strips by means of continuous hot-melt extrusion processing.

The aim of this study was to develop mucoadhesive oral strips using hot-melt extrusion as a continuous manufacturing process. Powder blends of ketoconazole, a water-insoluble drug - either hydroxypropyl methylcellulose (HPMC) or soluplus (SOL), sorbitol (SRB) and magnesium aluminometasilicate (MAS) were extruded to manufacture thin strips with 0.5-mm thickness. The presence of the inorganic metasilicate facilitated smooth processing of the extruded strips as it worked as an absorbent directly impacting on the extensive mixing of the drug/excipients inside the extruder barrel. The use of MAS also favoured the rapid hydration, swelling and eventual disintegration of the strips. Differential scanning calorimetry and transmission X-ray diffraction analysis revealed the existence of the amorphous drug within the extruded strips. Scanning electron microscopy and energy dispersive X-ray undertaken on the formulations showed a homogeneous drug distribution within the extruded strips. The strips produced via continuous hot-melt extrusion processing showed significantly faster release of ketoconazole compared to the bulk drug substance.

Development of Itraconazole Liquisolid Compact: Effect of Polyvinylpyrrolidone on the Dissolution Properties

The aim of this work was to utilize the liquisolid technique to enhance dissolution of itraconazole (ITZ). Liquisolid tablets of ITZ were formulated by using N-methyl-2-pyrrolidone as liquid vehicle, polyvinylpyrrolidone (PVP) as a precipitation inhibitor and magnesium aluminometasilicate Neusilin® as a carrier and coating material. The effect of PVP level on stability of liquid medication, physicomechnanical properties and dissolution rate of liquisolid compacts was studied in detail. The crystallinity of formulated drug and the interaction between excipients were examined by differential scanning calorimetry (DSC) and X-ray powder diffraction (XRPD). All the liquisolid tablets showed higher drug dissolution rates than the conventional, directly compressed tablets. The flowability of liquisolid powders was slightly improved as the proportion of PVP in ITZ-NMP mixture increased. Moreover, the stability of liquid medication and wetting ability of liquisolid tablets were improved by PVP. The presence of low amount of PVP (≤ 1%) in liquisolid formulation could enhance dissolution of ITZ liquisolid tablets, whereas the percentage of PVP over 5% decreased the dissolution of ITZ from liquisolid tablets. Both DSC and XRPD suggested reduction or loss of ITZ crystallinity upon liquisolid formulations indicating that the drug was almost solubilized and molecularly dispersed with excipients within the liquisolid matrix. It could be shown that increased solubility, wetting properties and surface area available for dissolution contributed to the improvement of the dissolution of ITZ from liquisolid tablets.

FORMULATION DEVELOPMENT, OPTIMIZATION &amp; IN VITRO CHARATERIZATION OF LIQUISOLID COMPACTS OF AN OXICAM DERIVATIVE

The rationale of the current research was to investigate the in vitro dissolution properties of poorly water soluble piroxicam by utilizing liquisolid technology. Dissimilar liquisoli compacts were formulated using a factorial design to estimate the required quantities of powder and liquid ingredients to fabricate adequately flowable and compressible admixture. About 16 different formulations were developed using factorial design with carriers Neusilin (Magnesium aluminometasilicate)Â and Avicel PH 102, binder PVP K-30 and vehicle PEG-400 as independent variables and Aerosil 200 is used as coating material. The In-vitro drug release from the LSC has used a dependent variable. The empirical method by Spireas and Bolton was applied to calculate the amounts of carrier and coating materials and obtained the improved flow characteristics and hardness by changing the proportion of carrier and coating materials. Liquid solid compacts were fabricated and evaluated for their tabletting properties. Fourier transform infrared (FTIR) analysis, differential scanning calorimetry (DSC) and X- ray powder diffraction (XRPD) were performed. The FTIR spectra showed disappearance of the characteristic absorption band of piroxicam (3338.78 cm-1) in liquisolid formulations which might be attributed to the formation of hydrogen bonding between the drug and liquid vehicle; this resulted in drug dissolution enhancement. A 23 factorial design is used and developed liquid soild compacts using Neusilin LSCN1 to LSCN8 and Avicel PH 102 LSCA1 to LSCA8. The physicochemical characterization of all formulations exhibited well within the specification limits with respect to weight variation, hardness, friability and content uniformity. Â The In-vitro drug release from these liquid soild compacts was evaluated in 0.1 N HCl and the optimized formulation LSCA8 was compared with pure drug (capsule) and physical mixture (tablet). The release studies suggested that the liquisolid tablets outcome in higher release profile than pure active pharmaceutical ingredient and physical mixture due to enhance in surface and wetting properties of the active pharmaceutical ingredient. Liquid solid compacts technique confirmed the enhanced dissolution rate of oxicam derivative, which in turn promotes in enhancing bioavailability. Keywords: Piroxicam, Factorial design, Solubility, Dissolution rate, Avicel PH 102

Properties and potential application of modern adsorbents in formulation of solid drug delivery systems

In latest years, many natural and synthetic solid carriers attract increasing attention, due to theirs biocompatibility, acceptable ecological and toxicological properties, possible modification of physico-chemical properties, simple production, high stability and relatively low price. These carriers have similar chemical structure, mostly based on silicon-dioxide, magnesium aluminometasilicate and calcium phosphate, and differ from each other in structure porosity, specific surface area, size, volume and shape of pores, and possibility of surface functionalization. Ordered mesoporous materials like MCM - 41 and SBA - 15, as well as porous materials from Neusilin® and Sylysia® groups, represent the most common adsorbents evaluated in order to increase drug dissolution rate, and its bioavailability, and also in modifiedand targeted drug release formulations. Also, natural silica material, isolated from diatomites, diatom microshells, with its unique characteristics, represents relatively cheap solid carrier used in formulation of oral dosage forms and implants. Modern adsorbents are mostly used in formulations of solid dispersions with low water-soluble drugs, or as solid carriers for lipid formulations. In latest years, modern porous carriers are evaluated for possible surface functionalization in order to achieve prolonged or signal-initiated drug release.