Enhanced Dissolution Rate Research Articles

Soil inorganic carbon sequestration through alkalinity regeneration using biologically induced weathering of rock powder and biochar

Soil inorganic carbon (SIC) accounts for about half of the C reserves worldwide and is considered more stable than soil organic carbon (SOC). However, soil acidification, driven mainly by nitrogen (N) fertilization can accelerate SIC losses, possibly leading to complete loss under continuous and intensive N fertilization. Carbonate-free soils are less fertile, productive, and more prone to erosion. Therefore, minimizing carbonate losses is essential for soil health and climate change mitigation. Rock/mineral residues or powder have been suggested as a cheaper source of amendments to increase soil alkalinity. However, slow mineral dissolution limits its efficient utilization. Soil microorganisms play a vital role in the weathering of rocks and their inoculation with mineral residues can enhance dissolution rates. Biochar is an alternative material for soil amendments, in particular, bone biochar (BBC) contains higher Ca and Mg that can induce even higher alkalinity. This review covers i) the contribution and mechanism of rock residues in alkalinity generation, ii) the role of biochar or BBC to soil alkalinity, and iii) the role of microbial inoculation for accelerating alkalinity generation through enhanced mineral dissolution. We conclude that using rock residues/BBC combined with microbial agents could mitigate soil acidification and SIC losses and also improve agricultural circularity.

Design and evaluation of in vivo bioavailability in beagle dogs of bilayer tablet consisting of immediate release nanosuspension and sustained release layers of rebamipide

The purpose of this study was to develop a once-daily, bilayer matrix tablet with immediate (IR) and sustained release (SR) layers of poorly water-soluble and absorption site dependent rebamipide (RBM) to substitute three times a day IR tablet. Owing to the pH-dependent poor water solubility of RBM in low pH condition, salt-caged nanosuspensions (NSPs) consisting of RBM and poloxamer 407 (POX 407) or poloxamer 188 (POX 188) were prepared using an acid-base neutralization method to increase the dissolution rate, which was subsequently applied to the immediate-release (IR) layer. Polyethylene oxide (PEO) with different molecular weights (PEO 100,000 and PEO 5,000,000) and hydroxypropyl methylcellulose 4000 (HPMC 4000) were then investigated as SR agents to incorporate into the SR layer with pure RBM via wet granulation method. The dissolution profile of the optimized bilayer tablet having 50% IR and 50% SR layer of 300 mg RBM showed that the IR layer could rapidly disintegrate in pH 1.2 buffer solution within 2 h, reaching 50% of drug release from the tablet, followed by an extended drug release from the SR layer in pH 6.8 buffer over 24 h. An in vivo pharmacokinetic study was carried out in beagle dogs to compare the optimal formulation (300 mg RBM bilayer tablet) and the commercial tablet (Mucosta® 100 mg) as a reference. Unexpectedly, despite enhanced dissolution rate in a controlled manner, a designed bilayer tablet had no dose- and dosage form dependent in vivo bioavailability in beagle dogs as compared with IR 100 mg RBM reference tablet. It was evident that solubility in low pH condition, gastric residence time and absorption site of RBM should be carefully considered for designing specific SR or gastroretentive dosage form to improve therapeutic outcomes.

QUALITY EVALUATION OF BRANDS OF PROPRANOLOL HCL TABLETS AVAILABLE ON IRAQI MARKET

Objective: The purpose of this study is to evaluate the quality control of marketed tablets containing propranolol hydrochloride available on the Iraqi market and manufactured by different companies. Methods: Different batches of propranolol hydrochloride 40 mg tablets were assessed using quality control tests. Weight variation, diameter, thickness, friability, disintegration time and dissolution study were carried out in this study. Results: Based on the data obtained in this study, all brands of PPL available on the Iraqi market showed weight variation within the acceptable limit of USP. Marketed products of Becardin and Propranolol lie within the acceptable limit of hardness and Inderal was observed to be slightly higher than the normal upper range of USP. Diameter and thickness for all brands were almost the same, except the diameter of Becardin was slightly higher and friability was zero for all brands. All brands demonstrated a time of disintegration of fewer than 30 min. The tested marketed propranolol products; Inderal, Procard, Becardin and Propranolol showed cumulative drug release of 90.08%, 94.46%, 92.4% and 79.51%, respectively at the end of the first 20 min. This variation in the release profile of marketed tablets of Propranolol HCl might be attributed to the excipients present in the marketed tablets where some of these excipients may behave as a disintegrant and enhance dissolution rate while others may act as dissolution retardants. Conclusion: All marketed tablets of Propranolol HCl employed in this study were produced within the standard criteria of tablet manufacturing. Evaluation of quality control of these selected tablets showed acceptable pharmaceutical properties that lie within the limits of USP.

Physical Characterization and In Vitro Evaluation of Dissolution Rate from Cefpodoxime Proxetil Loaded Self Solidifying Solid SNEDDS.

Cefpodoxime Proxetil (CPD) is a broad-spectrum cephalosporin indicated in respiratory and urinary tract infections. CPD is a BCS class IV drug with pH-dependent solubility and has poor bioavailability. This study investigated the challenges of developing ternary components based on solid SNEDDS of CPD for in vitro dissolution rate enhancement and self-solidifying behaviour. Tween 80, Transcutol and PEG6000 were employed as surfactants, solvents and solidifiers for a base of ternary components to develop self-solidifying solid SNEDDS, respectively. Ternary phase diagrams were used to characterize solidifying behaviour of ternary components in different proportions. S-SNEDDS formulations were drawn on the solidification areas available in the phase diagram and characterized for IR, XRD, DSC and in vitro drug release in various pH media. Ternary components for the preparation of self-solidifying solid SNEDDS were selected based on drug solubility. FTIR and DSC characterization studies ruled out any drug interaction between CPD and components chosen to prepare S-SNEDDS. CPD was transformed from a crystalline into an amorphous state in ternary dispersions as revealed from XRD data. Optimized formulation (S-S 1) demonstrated more than 95% of drug release irrespective of the pH environments of the medium. Calculation of dissolution efficiency and similarity factors indicate that S SNEDDS resulted in a higher drug dissolution rate over binary dispersion (p<0.01). The stability studies showed that the S SNEDDS were stable in performances and CPD assay. The present investigation provides an alternative approach for enhancing the CPD dissolution rate using self-solidifying solid SNEDDS exhibited solidification behaviour at ambient temperature conditions and drug loading, which could be exploited over conventional dosage form.

Frequency Dependent Silica Dissolution Rate Enhancement under Oscillating Pressure via an Electrochemical Pressure Solution-like, Surface Resonance Mechanism.

From atomic force microscopy (AFM) experiments, we report a new phenomenon in which the dissolution rate of fused silica is enhanced by more than 5 orders of magnitude by simply pressing a second, dissimilar surface against it and oscillating the contact pressure at low kHz frequencies in deionized water. The silica dissolution rate enhancement was found to exhibit a strong dependence on the pressure oscillation frequency consistent with a resonance effect. This harmonic enhancement of the silica dissolution rate was only observed at asymmetric material interfaces (e.g., diamond on silica) with no evidence of dissolution rate enhancement observed at symmetric material interfaces (i.e., silica on silica) within the experimental time scales. The apparent requirement for interface dissimilarity, the results of analogous experiments performed in anhydrous dodecane, and the observation that the silica "dissolution pits" continue to grow in size under contact stresses well below the silica yield stress refute a mechanical deformation or chemo-mechanical origin to the observed phenomenon. Instead, the silica dissolution rate enhancement exhibits characteristics consistent with a previously described 'electrochemical pressure solution' mechanism, albeit, with greatly amplified kinetics. Using a framework of electrochemical pressure solution, an electrochemical model of mineral dissolution, and a recently proposed "surface resonance" theory, we present an electro-chemo-mechanical mechanism that explains how oscillating the contact pressure between dissimilar surfaces in water can amplify surface dissolution rates by many orders of magnitude. This reaction rate enhancement mechanism has implications not only for dissolution but also for potentially other reactions occurring at the solid-liquid interface, e.g. catalysis.

Formulation and Assessment of Quick dissolving tablet of Candesartan cilexetil arranged from their circular agglomerates

Candesartan cilexetil is water insoluble drug which comes under BCS class second category. Drug was used in the treatment of acute and chronic hypertension. The research workgenerally focuses on the solubility enhancement, increasing dissolution behavior, flowability and compressibility of the drug. Tablets and capsule are the solid dosage form mostly used. Spherical agglomerates of Candesartan cilexetil were prepared. Candesartan cilexetil water insoluble drug was used. With the incorporation of polymer, Agglomerates of such drug was prepared. Fast dissolving tablet was prepared and evaluated. Evaluation parameter like FTIR, DSC was carried out. Precompression parameters like bulk density, tap density, angle of repose, compressibility index was carried out. Post compression parameters like friability, hardness, thickness, disintegration time, wetting time was carried out and evaluated. Effect of different disintegrant like Crospovidone, cross carmellose sodium was studied. From in vitro study it was found that cross carmellose sodium containing batch F3 shows better drug release so it shows enhanced dissolution rate while if cross carmellose sodium level increases thus decreasing their dissolution rate.

Enhancement of ketoprofen dissolution rate by the liquisolid technique: optimization and in vitro and in vivo investigations.

The objective of the current study is to evaluate the prospective of liquisolid formulation to improve the dissolution rate of ketoprofen and thereby the bioavailability. Different batches of liquisolid were prepared using polyethylene glycol 200 as a solvent, microcrystalline cellulose, and aerosil 200 as carrier and coating material, respectively. Central composite design (32) was utilized to examine the effects of independent variables (load factor and excipient ratio) on dependent variables (solubility and % in vitro drug release). Differential scanning calorimetry, Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy techniques were employed for characterization of optimized batch (LS-10) of liquisolid formulation. The half-maximal inhibitory concentration (IC50) values for in vitro anti-inflammatory activity for liquisolid formulation exhibited a higher anti-inflammatory effect than ketoprofen and physical mixture. The statistical analysis of in vivo (anti-inflammatory and analgesic) activities data demonstrated that the test (optimized formulation) treatment group resulted in quick pharmacological response in Wistar rats and Albino mice when compared with standard (pure drug) and control treatment groups. The results obtained in the present study illustrated that the liquisolid formulation could be a propitious approach to increase the bioavailability of ketoprofen and could be used in oral therapy.

Characterisation of spray dried microencapsules with amorphous lutein nanoparticles: Enhancement of processability, dissolution rate, and storage stability

Lutein has limited applicability in the food industry because of its poor water solubility and chemical instability. In this study, amorphous and crystalline lutein-loaded microencapsulated powders were prepared via wet media milling and spray drying techniques. The breakage kinetics, surface morphology, physicochemical characteristics, encapsulation efficiency, dissolution behaviour, and storage stability of the two types of microencapsules were determined. Compared with the crystalline formulation, amorphous lutein nanoparticles displayed better breakability (∼478.8 nm within 20 min) in the milling process and faster dissolution rates under both sink and supersaturation conditions (88.0 ± 1.7% and 47.0 ± 3.8%, respectively, within 2 min). Stability testing revealed that the amorphous formulation exhibited slower degradation rates, with decay constants k of 0.03 and 0.07 at 25 and 40 °C, respectively. Our study results suggest that microencapsules with amorphous lutein nanoparticles represent a commercially viable formulation for maintaining chemical stability and improving oral bioavailability.

Synthesis and structural characterization of two novel olanzapine cocrystals with decreased or enhanced dissolution rate

Olanzapine (OLZ) is a second-generation atypical anti-schizophrenia drug, and it had been developed into various formulations, including immediate release and long-acting formulations. Specific solubility properties of OLZ are very important to design formulations for specific administration. In present work, two novel cocrystals of OLZ were synthesized and characterized (OLZ-KAE·0.75EA·0.25H2O, OLZ-ORC, KAE = kaempferol, ORC = orcinol). Single crystal X-ray diffraction (SCXRD), powder X-ray diffraction (PXRD), synchronous thermal analysis and attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) were used to characterize the structure of the cocrystals. Hirshfeld surface analysis was used to understand intermolecular interactions in cocrystals. In OLZ-KAE·0.75EA·0.25H2O cocrystal, the ethyl acetate (EA) and H2O exist as channel crystalline solvate, and they can easily escape from the lattice channel. Powder dissolution study showed that OLZ-ORC improved the dissolution rate of OLZ in PH 6.8 phosphate buffer. However, OLZ-KAE·0.75EA·0.25H2O and its desolvation product decreased the dissolution rate of OLZ, and the release rate kept sustained and stable, which was very suitable for sustained release and long-acting muscle injection formulations.

Liquisolid Compact Technique for the Enhancement of Solubility and Dissolution Rate of Ambrisentan: Quality by Design Approach

Soluble epoxide hydrolase inhibitors have been reported as antihypertensive, anti-inflammatory, antiulcer and anticancer actions and protect the brain, heart and kidney from damage. Exploring soluble epoxide hydrolase inhibition activity of traditional medicinal plants helps to uncover the new target to treat various complications associated with inflammatory mediators. The present study was planned to explore soluble epoxide hydrolase inhibition activity of fifty medicinal plants commonly used in the traditional medicinal system. The dried plant material of each species was grounded into a coarse powder and separately macerated with absolute methanol and ethyl acetate for 7 d. Then the solvents were evaporated and obtained extracts were solubilized in dimethyl sulfoxide (10 mg/ml) and soluble epoxide hydrolase enzyme inhibitory potencies were evaluated using a fluorescent reporting system. Moreover, preliminary phytochemical screening and high-performance thin layer chromatography analysis were carried out for two extracts that showed potent soluble epoxide hydrolase inhibition activities. The results revealed that 10 methanolic extracts and 20 ethyl acetate extracts were potentially effective in suppressing soluble epoxide hydrolase activity with inhibitory concentration value of less than 10 μg/ml. Among the 30 potentially effective plants, four seed extracts (Celastrus paniculatus, Nigella sativa, Wrightia tinctorial, Vernonia anthhelmintica and Embelia ribes), one leaves extracts (Bergera koengii), one rhizome extracts (Curcuma longa) and one root extracts (Vetiveria zizanioides) were common in both methanolic and ethyl acetate extract. In conclusion, the study report suggests that various natural products used in the traditional medicinal system have many promising soluble epoxide hydrolase inhibitors. Methanolic extracts of seeds of Celastrus paniculatus and Nigella sativa have potent soluble epoxide hydrolase inhibition activities. Further research is warranted to identify a greater number of medicinal plants and active principles responsible for soluble epoxide hydrolase inhibition activities

Design of experiments assisted the development of inclusion complexes of ramipril using hydrophilic carriers for enhancement of solubility and dissolution rate

The goal of the present study was to develop inclusion complexes and polymers dispersions of ramipril prepared by physical mixing, kneading, co-evaporation, and solvent evaporation methods to enhance drug solubility and dissolution rate, and thereby to reduce drug dose and side effects using selected hydrophilic carriers such as β-CD, PVP-K25, PEG 4000, and HPMC K100M. The prepared formulations were characterized for solubility and in-vitro drug release studies. The systematic optimization of formulations was performed using I-Optimal experimental design by selecting factors such as type of carriers (X1), drug: carrier ratio (X2), and method of preparation (X3), and response variables including percent yield (Y1), solubility (Y2), Carr’s index (Y3) and drug release in 30 min (Y4). Mathematical modeling was carried out using a quadratic polynomial model. The inclusion complex formulation (F27) was selected as an optimized batch by numerical desirability function and graphical optimization with the help of design space. The inclusion complex prepared by the co-evaporation method showed maximum drug solubility and released in pH 6.8 phosphate buffer compared to pure and other formulations. The inclusion complex is a feasible approach to improve the solubility, dissolution rate, bioavailability, and minimization of drugs’ gastrointestinal toxicity upon oral administration of ramipril.

Enhancement of dissolution rate of racecadotril by liquisolid compact technology

The current investigation was used to improve the rate of dissolution of an anti-diarrheal drug i.e., racecadotril (RT) at low pH conditions (i.e., in the stomach) by reducing the water secretion and electrolyte in to the intestine by liquisolid tablets. Different formulations (liquisolid) were prepared using Avicel PH 102 as a carrier. Aerosil 200 as a coating material and sodium starch glycolate used as a disintegrant. Polyethylene glycol 200 was used as a non-volatile vehicle to dissolve the drug. FTIR, DSC, XRD and dissolution studies were conducted to characterise liquisolid tablets. Characterisation studies indicated that no interactions between carrier and drug. Solid state characterization had shown a reduction in crystallinity that further supports increment in solubility and dissolution. The optimised formulation showed a significant increase in dissolution i.e., 99.54±0.62% in 30 min compared to directly compressible tablets (38.47±0.26%). The % dissolution efficiency of racecadotril liquisolid tablets 76.86% compared to marketed tablet (27.56%) and conventional direct compression tablet (17.11%). Significant reduction in mean dissolution time of racecadotril from liquisolid tablets (6.84 min) compared to direct compression tablet (44.57 min), indicating faster release of drug and faster onset of action. Formulation of liquisolid tablets could enhance solubility, dissolution and bioavailability of racecadotril.

Enhancing solubility and bioavailability of coenzyme Q10: formulation of solid dispersions using Soluplus® as a carrier.

Improving the aqueous solubility of poorly soluble compounds have been a major issue in the pharmaceutical industry. In the present study, binary amorphous solid dispersions (SDs) of Coenzyme Q10 (CoQ10), a biopharmaceutics classification system (BCS) II compound and Soluplus® were prepared to enhance the solubility and pharmacokinetic properties compared to crystalline CoQ10. SDs were prepared with different ratios of CoQ10 and Soluplus® (1:3, 1:5, and 1:7) using spray drying technology, and the physicochemical properties of the SDs were evaluated. X-ray powder diffraction, differential scanning calorimetry, and scanning electron microscopy suggested the conversion of the crystalline form of CoQ10 to a binary amorphous system in the SDs. Fourier transform infrared spectroscopy revealed no potential interactions between CoQ10 and Soluplus®. The solubility of the optimal SD formulation (SD 1:7) was approximately 9000-fold higher than that of crystalline CoQ10, and the increment was Soluplus® concentration dependent. As a result, optimized SD 1:7 also showed significantly enhanced dissolution rate where maximum drug release was observed within 30min in two different dissolution media. Moreover, in contrast to crystalline CoQ10, CoQ10 SDs showed improved pharmacokinetic parameters. Thus, the SD 1:7 formulation is expected to improve biopharmaceutical properties and therapeutic efficacy of CoQ10.

Pharmaceutical Development of Micro and Nanocrystals of a Poorly Water-Soluble Drug: Dissolution Rate Enhancement of Praziquantel

Pharmaceutical Development of Micro and Nanocrystals of a Poorly Water-Soluble Drug: Dissolution Rate Enhancement of Praziquantel

PREPARATION, CHARACTERIZATION AND DISSOLUTION STUDY OF SPRAY DRIED SOLID DISPERSIONS OF SIMVASTATIN WITH PVP K25 AND AEROSIL 200

BCS class II is well-known for the drugs, having poor aqueous solubility and high permeability. Simvastatin is also categorized as BCS class II, suffering from poor aqueous solubility, affecting its bioavailability. In an attempt to resolve this problem, solid dispersions of simvastatin were prepared by spray-drying method. Solid dispersions of simvastatin with PVP K25 and aerosol in ratio (1:1:1 to 1:5:1) and without aerosil 200 (1:1 to 1:5) were prepared by spray drying method. The dissolution test showed the enhancement of dissolution as compared to the pure drug and nearly equal to marketed formulation “SIMVOTIN 20mg” in both types of formulation, but formulations with aerosil 200 showed faster drug release as compared to the simple formulations without aerosil. The formulation containing the 1:3:1 (simvastatin: PVP K25: Aerosil 200) showed the faster drug release as compared to other formulation that do not contain the Aerosil 200. Other characterization studies were also performed such as FTIR, differential scanning colorimetry and powdered X-ray crystallographic studies. These studies showed the increased amorphous nature of the drug in the formulation, which explain the enhanced dissolution rate of the drug for these formulations.

Increase in Dissolution Rate of Zotepine via Nanomilling Process - Impact of Dried Nanocrystalline Suspensions on Bioavailability.

Zotepine is an atypical antipsychotic drug used in the treatment of schizophrenia. However, its poor dissolution properties limit its therapeutic efficacy. In this investigation, a series of nanosuspension-containing zotepine were prepared employing media milling method with an aim to improve its dissolution properties and oral bioavailability. Briefly, Box-Behnken design was applied to investigate the influence of various independent variables such as X1- amount of stabilizer, X2- amount of milling agent, and X3- milling time on the performance of the formulation. Dissolution studies revealed enhancement of dissolution rate as compared to pure drug. Solid state characterization (DSC, PXRD, and SEM) studies demonstrated no polymorphic changes in drug after lyophilization of media-milled nanosuspension. In vivo pharmacokinetic studies of lyophilized nanosuspension was carried out in rat and the results exhibited significant improvement in Cmax and AUC0-t, about 450.0 and 287.45%, respectively, suggesting amelioration in oral bioavailability by 2.87-fold higher as compared to pure drug. Accelerated stability studies of the optimized lyophilized formulation at 40°C and 75% RH suggested stability of the nanocrystals for at least a 6-month period. The obtained nanocrystals successfully showed dissolution enhancement and improved oral bioavailability of poorly water-soluble drug, zotepine.

Cyclodextrin Complexed Lipid Nanoparticles of Irbesartan for Oral Applications: Design, Development, and In Vitro Characterization.

Irbesartan (IR) is an angiotensin II receptor antagonist drug with antihypertensive activity. IR bioavailability is limited due to poor solubility and first-pass metabolism. The current investigation aimed to design, develop, and characterize the cyclodextrin(s) (CD) complexed IR (IR-CD) loaded solid lipid nanoparticles (IR-CD-SLNs) for enhanced solubility, sustained release behavior, and subsequently improved bioavailability through oral administration. Based on phase solubility studies, solid complexes were prepared by the coacervation followed by lyophilization method and characterized for drug content, inclusion efficiency, solubility, and in vitro dissolution. IR-CD inclusion complexes demonstrated enhancement of solubility and dissolution rate of IR. However, the dissolution efficiency was significantly increased with hydroxypropyl-βCD (HP-βCD) inclusion complex than beta-CD (βCD). SLNs were obtained by hot homogenization coupled with the ultrasonication method with IR/HP-βCD inclusion complex loaded into Dynasan 112 and glycerol monostearate (GMS). SLNs were evaluated for physicochemical characteristics, in vitro release, differential scanning calorimetry (DSC), powder X-ray diffractometry (PXRD), and physical stability at room temperature for two months. The optimized SLNs formulation showed particle size, polydispersity index, zeta potential, assay, and entrapment efficiency of 257.6 ± 5.1 nm, 0.21 ± 0.03, −30.5 ± 4.1 mV, 99.8 ± 2.5, and 93.7 ± 2.5%, respectively. IR-CD-SLN and IR-SLN dispersions showed sustained release of IR compared to the IR-CD inclusion complexes. DSC results complimented PXRD results by the absence of IR endothermic peak. Optimized IR-CD complex, IR-SLN, and IR-CD-SLN formulations were stable for two months at room temperature. Thus, the current IR oral formulation may exhibit improved oral bioavailability and prolonged antihypertensive activity, which may improve therapeutic outcomes in the treatment of hypertension and heart failure.

Formulation and Characterization of Nimodipine Nanoparticles for the Enhancement of solubility and dissolution rate

Nimodipine (NMD) is a dihydropyridine calcium channel blocker useful for the prevention and treatment of delayed ischemic effects. It belongs to class ? drugs, which is characterized by low solubility and high permeability. This research aimed to prepare Nimodipine nanoparticles (NMD NPs) for the enhancement of solubility and dissolution rate. The formulation of nanoparticles was done by the solvent anti-solvent technique using either magnetic stirrer or bath sonicator for maintaining the motion of the antisolvent phase. Five different stabilizers were used to prepare NMD NPs( TPGS, Soluplus®, HPMC E5, PVP K90, and poloxamer 407). The selected formula F2, in which Soluplus &#x0D; has been utilized as a stabilizer, has a particle size (77 nm) and polydispersity index (PDI) (0.016). The formulas with the smallest particle size were freeze dried with the addition of 1 % w/w mannitol as cryoprotectant. The saturation solubility of NMD in the prepared nanoparticles was increased twenty four-folds, and the complete dissolution was achieved at 90 minutes compared with pure NMD, which reaches only 6%. The formation of hydrogen bonding between NMD and the polymer or the cryoprotectant, as confirmed by the FTIR study. In conclusion, the preparation of NMD as polymeric nanoparticles is a useful technique for enhancing the solubility and dissolution rate.

Mechanistic study of dissolution enhancement by interactive mixtures of chitosan with meloxicam as model

To enhance dissolution rate of meloxicam (MX), a poorly soluble model drug, a natural polysaccharide excipient chitosan (CH) is employed in this work as a carrier to prepare binary interactive mixtures by either mixing or co-milling techniques. The MX-CH mixtures of three different drug loads were characterized for morphological, granulometric, and thermal properties as well as drug crystallinity. The relative dissolution rate of MX was determined in phosphate buffer of pH 6.8 using the USP-4 apparatus; a significant increase in MX dissolution rate was observed for both mixed and co-milled mixtures comparing to the raw drug. Higher dissolution rate of MX was evidently connected to surface activation by mixing or milling, which was pronounced by the higher specific surface energy as detected by inverse gas chromatography. In addition to the particle size reduction, the carrier effect of the CH was confirmed for co-milling by linear regression between the MX maximum relative dissolution rate and the total surface area of the mixture (R2 = 0.863). No MX amorphization or crystalline structure change were detected. The work of adhesion/cohesion ratio of 0.9 supports the existence of preferential adherence of MX to the coarse particles of CH to form stable interactive mixtures.

Formulation and Optimization of Polyherbal Fast Dissolving Tablet of Curcumin, Quercetin and Rutin

The current study was focused on the design, development, and evaluation of the fast-dissolving tablet of a polyherbal combination of curcumin, quercetin, and rutin. These herbal drugs are poorly water-soluble. The center of attention for this study is to provide quick onset of action, improved bioavailability, and increased patient compliance for administering a tablet. All parameters of Polyherbal Fast dissolving tablets were evaluated, and all were found within the official range. Drug content ranges between 90 to 105%. The formulation PHT24 containing a high concentration of Crosspovidone enhanced the drug release up to 94% within 5 minutes compared with the control. The optimized formula PHT24 showed favorable drug dissolve characteristics with better mouth feel and acceptable fast-dissolving properties. It was also observed that all formulations were acceptable with reasonable limits of the standard required for fast-dissolving tablets. The study also reveals that the Superdisintegrants used were effective in low or high concentrations. It was concluded that fast dissolving tablets with enhanced dissolution rates could be made using selected Superdisintegrants.