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Flurbiprofen (FBP), a nonsteroidal anti-inflammatory drug (NSAID), is commonly used to treat the pain of rheumatoid arthritis, but in prolonged use it causes gastric irritation and ulcer. To avoid these adverse events of NSAIDs, the simultaneous administration of H2 receptor antagonists such as ranitidine hydrochloride (RHCl) is obligatory. Here, we developed composite oral fast-disintegrating films (ODFs) containing FBP along with RHCl to provide a gastroprotective effect as well as to enhance the solubility and bioavailability of FBP. The ternary solid dispersion (TSD) of FBP was fabricated with Syloid® 244FP and poloxamer® 188 using the solvent evaporation technique. The synthesized FBP-TSD (coded as TSD) was loaded alone (S1) and in combination with plain RHCl (S2) in the composite ODFs based on hydroxypropyl methyl cellulose E5 (HPMC E5). The synthesized composite ODFs were evaluated by in vitro (thickness, folding endurance, tensile strength, disintegration, SEM, FTIR, XRD and release study) and in vivo (analgesic, anti-inflammatory activity, pro-inflammatory cytokines and gastroprotective assay) studies. The in vitro characterization revealed that TSD preserved its integrity and was effectively loaded in S1 and S2 with optimal compatibility. The films were durable and flexible with a disintegration time ≈15 s. The release profile at pH 6.8 showed that the solid dispersion of FBP improved the drug solubility and release when compared with pure FBP. After in vitro studies, it was observed that the analgesic and anti-inflammatory activity of S2 was higher than that of pure FBP and other synthesized formulations (TSD and S1). Similarly, the level of cytokines (TNF-α and IL-6) was also markedly reduced by S2. Furthermore, a gastroprotective assay confirmed that S2 has a higher safety profile in comparison to pure FBP and other synthesized formulations (TSD and S1). Thus, composite ODF (S2) can effectively enhance the FBP solubility and its therapeutic efficacy, along with its gastroprotective effect. [ABSTRACT FROM AUTHOR]

Here, we evaluate the feasibility of co-loading plain ranitidine hydrochloride (RHCl) and microencapsulated flurbiprofen (FBP) in a Lycoat® RS780-based oral fast disintegrating film (ODF). These films were developed by the solvent casting method to minimize the adverse effects of FBP and reduce the dosage form burden on patients. Optimized FBP microparticles (M3) with an average size of 21.2 ± 9.2 µm were loaded alone (F1) and in combination with plain RHCl (F2) in the composite ODF. All films were evaluated physicomechanically and physicochemically. These films were resilient, flexible, and disintegrated within thirty seconds. SEM images showed intact FBP microparticles in both formulations and, moreover, did not observe an interaction between the drug and film components. Microencapsulated FBP was released in a controlled manner over 48 h from the proposed formulations, while RHCl was released within 5 min from F2. After in vitro evaluation, formulations were also tested for in vivo anti-inflammatory activity, cytokine (TNF-α and IL-6) levels, and gastroprotective effects in rats. The anti-inflammatory activity and gastroprotective effect of F2 were markedly higher than pure FBP and other synthesized formulations (M3 and F1). The average score of gastric lesions was in the order of pure FBP (15.5 ± 1.32) > M3 (8 ± 2) > F1 (1 ± 0.5) > F2 (0.5 ± 0) > control (0). Additionally, F2 showed a sustained anti-inflammatory effect up to 10 h in the rat paw edema model. Furthermore, F2 also markedly reduced TNF-α and IL-6 levels. Conclusively, the Lycoat® RS780-based composite film could be a promising carrier for the co-loading of microencapsulated FBP with RHCl. In the future, an optimized formulation (F2) could be capable of countering the issues related to multiple drug administration in geriatric patients and evading the gastric irritation associated with FBP. [ABSTRACT FROM AUTHOR]

Two metal oxide nanoparticles, magnesium oxide nanoparticles (MgONPs) and aluminum oxide nanoparticles (Al2O3NPs), were synthesized from green sources, Salvia officials and Cuminum cyminum seed extract, respectively. These nanoparticles were used for construction of potentiometric enhancement sensors employed for the estimation of ranitidine hydrochloride (RNT) in authentic powder and commercial products. The electroactive substance ranitidine-phosphotungstate (RNT-PT) was formed by combining RNT with phosphotungstic acid (PTA) in the presence of plasticizing material o-nitrophenyloctyl ether (o-NPOE). The outcomes showed that the enhanced MgO and Al2O3 nanosensors behaved linearly across the concentration ranges 1.0 × 10−9–1.0 × 10−2 and 1.0 × 10−10–1.0 × 10−2 mol L−1, respectively. However, the conventional sensor (RNT-PT) displayed a linearity over 1.0 × 10−6–1.0 × 10−2 mol L−1. Least square equations were calculated as EmV = (54.1 ± 0.5) log (RNT) + 762.33, EmV = (58.6 ± 0.2) log (RNT) + 696.48, and EmV = (52.2 ± 0.7) log (RNT) + 756.76 for enriched nanometal oxides modified and conventional sensors, respectively. The correlation coefficients of regression equations were 0.9997, 0.9995, and 0.9992 for the above suggested sensors, respectively. The recorded results showed excellent sensitivity and selectivity of the modified nanometal oxide sensors for the quantification of the analyzed drug in its authentic samples and commercial products. [ABSTRACT FROM AUTHOR]

Here, we evaluate the feasibility of co-loading plain ranitidine hydrochloride (RHCl) and microencapsulated flurbiprofen (FBP) in a Lycoat® RS780-based oral fast disintegrating film (ODF). These films were developed by the solvent casting method to minimize the adverse effects of FBP and reduce the dosage form burden on patients. Optimized FBP microparticles (M3) with an average size of 21.2 ± 9.2 µm were loaded alone (F1) and in combination with plain RHCl (F2) in the composite ODF. All films were evaluated physicomechanically and physicochemically. These films were resilient, flexible, and disintegrated within thirty seconds. SEM images showed intact FBP microparticles in both formulations and, moreover, did not observe an interaction between the drug and film components. Microencapsulated FBP was released in a controlled manner over 48 h from the proposed formulations, while RHCl was released within 5 min from F2. After in vitro evaluation, formulations were also tested for in vivo anti-inflammatory activity, cytokine (TNF-α and IL-6) levels, and gastroprotective effects in rats. The anti-inflammatory activity and gastroprotective effect of F2 were markedly higher than pure FBP and other synthesized formulations (M3 and F1). The average score of gastric lesions was in the order of pure FBP (15.5 ± 1.32) > M3 (8 ± 2) > F1 (1 ± 0.5) > F2 (0.5 ± 0) > control (0). Additionally, F2 showed a sustained anti-inflammatory effect up to 10 h in the rat paw edema model. Furthermore, F2 also markedly reduced TNF-α and IL-6 levels. Conclusively, the Lycoat® RS780-based composite film could be a promising carrier for the co-loading of microencapsulated FBP with RHCl. In the future, an optimized formulation (F2) could be capable of countering the issues related to multiple drug administration in geriatric patients and evading the gastric irritation associated with FBP.

Density and ultrasonic velocity values of antacid drug ranitidine hydrochloride + water /methanol-water/ethanol-water mixtures have been measured as a function of drug concentration and solvent composition from (T = 303.15–313.15) K. The thermodynamic properties such as isentropic compressibility, specific acoustical impedance, relative association and intermolecular free length have been calculated from density and ultrasonic velocity. It is observed that the solvent composition and temperature strongly affect the measured and calculated properties. It has been observed from the acoustical properties that the solvation of drug increases with concentration and nature of alcohol. [ABSTRACT FROM AUTHOR]

Ranitidine hydrochloride (RH) resinates were prepared by bath method using a highly acidic cation-exchange resin as the carrier. The drug-resinates combination pattern was characterized by DSC and X-ray diffraction. The influences of the types of the ion-exchange resin, initial RH concentration and the reaction temperature on the process of ion exchange were investigated. Three empirical kinetics models and thermodynamics equations were studied to the ion exchange process under different temperatures. The results showed that RH combined with ion-exchange resin not simple physical mixture but by ion bond, and the rate of ion exchange increased on increasing the initial drug concentration and reducing the temperature the resin. The in vitro drug release test showed that the release process was affected by the kind of countra-ion, ionic strength and temperature. Thermodynamics results showed that the ion exchange reaction between RH and cation-exchange resin was exothermic (ΔHθ r,m<0), and the drug release process could preferably be fitted with the first order equation. In conclusion, RH resinates were prepared by the bath method with strongly acidic cation-exchange (Amberlite® IRP69) with 5 mg/mL RH solution(100mL) stirred at 298K for 1h. Drug release from resinates was fitted with Viswanathan equation, and to achieve obvious sustained-release effect, the RH-resin complex should be further coated with a semipermeable membrane. [ABSTRACT FROM AUTHOR]

The class of medicines most used for the treatment of gastric disorders is histamine H2 receptor inhibitors, reducing the gastric acid secretion. Ranitidine hydrochloride is one of the most used agents of this class, usually found as 150 and 300 mg tablets. Dispensing extemporaneous compounds has been shown as alternative when patient seeks for medicines with personalized doses or lower cost, resulting in a progressive increase of this type of medicine. Aiming to evaluate the quality of extemporaneous compounding, this work verified the quality of ranitidine hydrochloride capsules from three compounding pharmacies (F1, F2 and F3) of the state of Mato Grosso. Trials were conducted according to Brazilian Pharmacopeia. Results showed that compounded capsules from F1 and F3 met the Brazilian Pharmacopeia specifications while the F2 ones were out of specification limits. Therefore, it was observed that it is needed a strict control over the compounding process to assure quality, effective and safe products.

The solid-state properties of drug candidates play a crucial role in their selection. Quality control of active pharmaceutical ingredients (APIs) based on their structural information involves ensuring a consistent crystal form and controlling water and residual solvent contents. However, traditional crystallographic techniques have limitations and require high-quality single crystals for structural analysis. Microcrystal electron diffraction (microED) overcomes these challenges by analyzing difficult-to-crystallize or small-quantity samples, making it valuable for efficient drug development. In this study, microED analysis was able to rapidly determine the configuration of two crystal forms (Forms 1, 2) of the API ranitidine hydrochloride. The structures obtained with microED are consistent with previous structures determined by X-ray diffraction, indicating microED is a useful tool for rapidly analyzing molecular structures in drug development and materials science research.

The purpose of the study was to develop a novel, directly compressible, co-processed excipient capable of providing a controlled-release drug system for the pharmaceutical industry. A co-processed powder was formed by adsorption of solid lipid nanoparticles (SLN) as a controlled-release film onto a functional excipient, in this case, dicalcium phosphate dihydrate (DPD), for direct compression (Di-Tab®). The co-processed excipient has advantages: easy to implement; solvent-free; industrial scaling-up; good rheological and compressibility properties; and the capability to form an inert platform. Six different batches of Di-Tab®:SLN weight ratios were prepared (4:0.6, 3:0.6, 2:0.6, 1:0.6, 0.5:0.6, and 0.25:0.6). BCS class III ranitidine hydrochloride was selected as a drug model to evaluate the mixture’s controlled-release capabilities. The co-processed excipients were characterized in terms of powder rheology and dissolution rate. The best Di-Tab®:SLN ratio proved to be 2:0.6, as it showed high functionality with good flow and compressibility properties (Carr Index = 16 ± 1, Hausner Index = 1.19 ± 0.04). This ratio could control release for up to 8 h, so it fits the ideal profile calculated based on biopharmaceutical data. The compressed systems obtained using this powder mixture behave as a matrix platform in which Fickian diffusion governs the release. The Higuchi model can explain their behavior.

Objectives: The aim of this research was to assess regional difference in the intestinal absorption of ranitidine HCl as an indicator for the potential effect of P‐glycoprotein (P‐gp) efflux transporters. Methods: In situ rabbit intestinal perfusion was used to investigate absorption of ranitidine HCl, a substrate for P‐gp efflux from duodenum, jejunum, ileum and colon. This was conducted both in the presence and absence of piperine as P‐gp inhibitor. Key findings: Ranitidine HCl was incompletely absorbed from rabbit intestine. The length normalized absorptive clearance (PeA/L) of ranitidine HCl was ranked as colon > duodenum > jejunum > ileum. This is the reverse order of the magnitude of P‐gp expression. Coperfusion of piperine with ranitidine HCl significantly increased the PeA/L of ranitidine HCl from jejunum and ileum with no significant change on the absorption from duodenum and colon. This was confirmed by significant reduction in the length required for complete ranitidine HCl absorption from jejunum and ileum in presence piperine. Conclusions: The results indicate that P‐gp transporters play a major role in determining regional difference in intestinal absorption of ranitidine HCl. Thus, the regional absorption of drugs may be taken as an indirect indication for the role of P‐gp in intestinal absorption. [ABSTRACT FROM AUTHOR]

Sorption removal of ranitidine hydrochloride (RH) from aqueous solution, using activated carbon obtained from Lagenaria siceraria activated carbon (LSAC), in the presence and absence of ultrasound, was investigated in batch mode. Characterization of material by Brunauer–Emmett–Teller analysis shows high surface area of 665 m2/g. The value of pHPZC is found to be 7.2. The Fourier transform infrared spectroscopy spectrum is typical for carbon materials. Scanning electron microscopy and energy-dispersive X-ray spectroscopy (EDS) analyses show porous, sponge-like, and amorphous structure, with high carbon content, and very small amount of oxygen. In addition, Boehm's analysis indicates relatively small amount of oxygen functional groups. Time for sorption equilibrium was about six times shorter in presence of ultrasound. The Langmuir isotherm and pseudo-second order kinetic model the best describe the RH removal process, indicating monolayer sorption. Sorption capacity of LSAC increases by influence of ultrasound, and maximal sorption capacities are 328.71, 389.84, and 425.43 mg/g for power of 0, 25, and 50 W, respectively. When temperature increased from 10°C to 30°C, sorption capacity decreased. Thermodynamic analysis showed that sorption was exothermic and spontaneous, implying the physisorption mechanism of RH removal by LSAC. [ABSTRACT FROM AUTHOR]

Objective: Oral gastroretentive system is one of the site-specific drug delivery system, which is designed to be retained in upper GIT for a prolonged time. Ranitidine hydrochloride (RHCl), which is used frequently in treatment of peptic ulcer, is a suitable candidate for gastroretentive delivery systems. Dependently, floating oil-entrapped alginate beads of RHCl were developed and evaluated as an approach to site-specific delivery avoiding colonic degradation and enhancing both bioavailability and the proposed local effect. Methods: Different formulations of floating beads were suggested and randomized using 24 full factorial design. Optimized formulation was subjected for in vivo studies to measure the oral bioavailability and the healing effect of induced peptic ulcers. Results: Beads size ranged from 1.32 to 2.3 mm. All beads revealed excellent floating capabilities. Optimum formulation (F12) has entrapment efficiency of 70%, drug loading of 7% and 71% RHCl released after 6 h. SEM of F12 shows a grossly spherical structure with presence of oil droplets distributed throughout structure. AUC obtained from F12 was nonsignificantly higher than that of a commercial tablet. Signs of ulcer healing appeared clearly with F12 through appearance of granulation tissue, collagen fibers and newly formed blood vessels. Healing rate and extent obtained with a commercial tablet were less than F12. Quantitative analysis confirmed histopathological findings. Conclusion: Floating oil-entrapped beads are a promising approach for RHCl delivery to remain in stomach for a longer time ensuring site-specific delivery and consequently, enhancing local healing effect of peptic ulcers. [ABSTRACT FROM AUTHOR]

Incorporation and controlled release of active substances from the conductive polypyrrole films by electric stimulation were investigated. Change of the redox state of the conductive polymer was induced by this stimulation, which allowed the incorporation and release of the drug at different rates. Polymerization of pyrrol on a stainless steel substrate was performed by cycling the potential 40 times in predetermined potential window, after which uniform polymeric film was formed and used as a medium for incorporation and release of the active substance. Stability of obtained films, as well as the electrochemical behaviour of ranitidine hydrochloride was investigated by cycling the potential of the film electrode in 0.9 % NaCl in the same potential window used for the polymerization. Uptake and release of the active substance was performed at constant potential and monitored by chronoamperometry. Although incorporation of the ranitidine hydrochloride was not obvious from the measured infrared spectra, incorporation and release was confirmed and quantified by monitoring the concentration of the active substance in the electrolyte. It was determined that maximum reversible uptake was 351 µg cm-2. However, successive potential stimuli did not result in the equal released quantity, as expected for the ideal controlledrelease system based on conducting polymers. [ABSTRACT FROM AUTHOR]

In this study, the feasibility of using microwave-irradiated Aegle marmelos Correa fruit shell was investigated in a fixed-bed column towards sorptive removal of ranitidine hydrochloride (RH) from simulated aqueous solution. Characterizations of adsorbent such as SEM, point of zero charge, BET surface area, Boehm surface functional groups, thermal and elemental analysis were carried out. Box-Behnken response surface methodology was utilized to optimize the process parameters such as influent flow rate (2.5-4.5 ml min−1), initial RH concentration (100-200 mg l−1), adsorbent particle size (0.082-0.20 mm), and fixed-bed height (5-10 cm). The highest fixed-bed adsorptive removal of RH at optimum conditions viz. bed height 9.19 cm, initial RH concentration 184.94 mg l−1, flow rate 3.76 ml min−1 and adsorbent particle size 0.2 mm was estimated to be 72.86%. Fixed-bed adsorption experiments were carried out at optimum conditions obtained at different bed heights, and the data obtained were fitted into different kinetic models to predict the applicable breakthrough curve model. Dose-response model was observed to be the best suited model for mathematical description of RH removal in fixed-bed column studies over other selected models. [ABSTRACT FROM AUTHOR]

Two zwitterionic stationary phases with largely corroborated capacities were obtained by attachment sulfobetaine monomers (H2C=CHC6H4CH2N+(CH3)2-CH2-SO3 - and H2C=CHC6H4CH2N+(CH3)2-(CH2)5-SO3 -) onto a PS/DVB particles were investigated for chromatographic separation of ranitidine hydrochloride. The different chain lengths are used as an investigative tool for the retention behavior of pharmaceutical ranitidine hydrochloride. The retention behavior of ranitidine hydrochloride was examined with eluent at various ACN contain, buffer concentrations and pH. The separation mechanism is based on partitioning in reversed phase and ZIC ion exchange resulting in a mixed mode for the ranitidine hydrochloride. A direct calibration graph was constructed for ZIC1 and ZIC5 columns and it was found that the linear range (10-1000 ng.ml-1), RSD% (0.41-1.55), LOD (1.55 and 2.56 ng.ml-1), LOQ (5.17 and 8.53 ng.ml-1), Recovery% (101.06 ± 1.15 and 100.47 ± 0.12) and Erel% (1.666 ± 0.78 and 0.47 ± 0.12), respectively. [ABSTRACT FROM AUTHOR]

The present study investigated the feasibility of utilizing Parthenium hysterophorus derived activated N-biochar (PH-ANB) as a potential low cost adsorbent for the effective removal of micro-pollutant and water-soluble cationic pharmaceutical ranitidine hydrochloride (RH) from simulated aqueous system. The structural characteristic features of PH-ANB were analysed using FTIR, SEM, BET and point of zero charge (pHPZC). The process of RH removal was conducted under the influence of varying parameters viz. adsorbent dose (0.01 g–0.1 g), contact time (5 min–180 min), pH (2–10), speed of agitation (40–240 rpm), temperature (293–313 K) and initial RH concentration (25–200 mg L−1) by performing a sequence of single parametric batch sorption experiments. The parametric conditions at which more than 99% removal of RH achieved were: adsorbent dose 0.05 g L−1, agitation speed 120 rpm, pH 2, equilibrium time 90 min and temperature 20 °C. The isothermal Langmuir model was well fitted with the equilibrium adsorption data while kinetic data suggested pseudo second order kinetics. The effects of process parameters on the removal efficiency of RH was optimized following the experimental matrix developed through a 23 full factorial central composite design (CCD) method of response surface methodology (RSM). The ideinvestigational data was then used to train artificial neural network (ANN). Results showed that ANN has superior predictability than RSM in optimization of RH removal. The study suggested that PH-ANB could be a reasonable and promising adsorbent for the elimination of RH from aqueous solution. [ABSTRACT FROM AUTHOR]

The main aim of the present work is to formulate and evaluate a chronotherapeutic drug delivery system of ranitidine hydrochloride using suitable mucoadhesive polymers by press coating technique. For elucidating the effect of formulation factors of press coated tablets a 33 full factorial design was employed. The effect of two factors, ratio of hydroxy propyl methyl cellulose (HPMC) K4M to ethyl cellulose (EC) in the core (X1) and ratio of HPMC K4M to carbopol 934P in the coat(X2) as independent variables. Y1 (drug release lag time), Y2 (% drug release after 6 hours) and Y3 (mucoadhesion strength) were selected as dependent variables. Thirteen formulations were formulated and subjected to various physiochemical evaluations like weight variation, friability, hardness, drug content, in vitro drug release and kinetic studies, swelling index and ex vivo mucoadhesion studies. The optimum formulation consists of ranitidine HCl 150mg, HPMC K4M: EC (0.72:1) in the inner core and HPMC K4M: carbopol 934P (1:1) in the outer coat with drug release lag time 1.89 hrs, cumulative % drug release after 6 hrs 41.15% and mucoadhesion strength 43.67 g. Ranitidine HCl tablets exhibited zero order release kinetics, resulting in regulated and complete release until 11 hrs. [ABSTRACT FROM AUTHOR]

Objective: In this study efforts have been made to design a drug delivery system based on a superporous hydrogel composite, for floating and sustained delivery of Ranitidine hydrochloride. Materials and Methods: The characterization studies were performed by the measurement of apparent density, porosity, swelling studies, mechanical strength studies, and scanning electron microscopy studies. The prepared formulation was evaluated for buoyant behavior, in vitro drug release, kinetics of drug release, and stability. The release profile of Ranitidine hydrochloride was investigated by changing the release retardant polymer in the formulation. To ascertain the kinetics of drug release, the drug release profiles were fitted to mathematical models that included zero-order, first-order, Higuchi, Hixson-Crowell, Korsmeyer-Peppas, Weibull, and Hopfenberg models. Results: Scanning electron microscopy images clearly indicated the formation of interconnected pores and capillary channels, and cross-linked Chitosan molecules were observed around the peripheries of the pores. The prepared drug delivery system floated and delivered the Ranitidine hydrochloride for about 17 hours. The in vitro drug release from the proposed system was best explained by the Korsmeyer-Peppas model. The values of the diffusion exponent in the Korsmeyer-Peppas model ranged between 0.47 ± 0.02 and 0.66 ± 0.02, which appeared to indicate a coupling of the diffusion and erosion mechanisms, anomalous non-Fickian transport. Conclusion: It was concluded that the proposed floating drug delivery system, based on the superporous hydrogel composite containing Chitosan as a composite material, is promising for stomach-specific delivery of Ranitidine hydrochloride.

The removal of ranitidine hydrochloride (RH) from simulated pharmaceutical aqueous solution using steam-activated charcoal from mung bean husk (MBH) by batch adsorption technique was investigated. The adsorbent was characterized by Brunauer–Emmett–Teller surface area analyzer, SEM, and point of zero charge. The influence of three process parameters such as adsorbent dose, solution pH, and agitation on the performance of the activated carbon was studied. The removal of 100 mg L−1RH was 99.16% at pH 2, adsorbent dose 0.75 gm L−1, and agitation speed of 180 rpm. The effects of process parameters on the removal efficiency were optimized as per central composite design of response surface methodology (RSM), and the same design was used for training set for artificial neural network (ANN). The results showed that ANN has better prediction capability as compared to RSM and SAC developed from MBH could be a promising adsorbent for RH removal from simulated pharmaceutical waste. [ABSTRACT FROM AUTHOR]

The present study was aimed to prepare and evaluate raft forming chewable tablets of ranitidine hydrochloride for effective treatment of Gastro Esophageal Reflux Disease.. The tablets were evaluated for various physicochemical parameters and in vitro drug release study. Tablets have shown satisfactory results when evaluated for hardness, friability, weight variation, drug content, raft strength and acid neutralizing capacity. Out of all factorial batches i.e. PB1 to PB10, PB8 has shown promising results of raft strength as it is sufficient for the prevention of the reflux in the esophagus. [ABSTRACT FROM AUTHOR]

The present investigation highlights the sorption of ranitidine hydrochloride (RH) from aqueous solution onto superheated steam activated mung bean husk derived biochar (SMBB) in fixed bed column. The SMBB were well characterized by Brunauer–Emmett–Teller (BET) surface area analyzer, Fourier transform IR spectroscopy (FTIR), scanning electron microscope (SEM), point of zero charge (pH PZC ) and X-ray diffractory (XRD). The influence of various parameters viz. bed depths (1, 2, and 3 cm), RH initial concentrations (100, 150, and 200 mg/L), and volumetric flow rates (2.0, 4.0, and 6.0 ml/min) on the performance of the breakthrough curve was studied. The highest adsorptive capacity of sorbent was observed to be 12 mg/g using bed height 3 cm, flow rate 2 ml/min and inlet RH concentration 200 mg/L. The breakthrough time was found to increase with increase in bed depth, and decrease with increase in initial concentration and volumetric flow rate. Among all the kinetic models examined, Yoon–Nelson model was found to be most suitable for simulation of the breakthrough curve of RH uptake on SMBB in fixed bed column. The study revealed that SMBB could be a potential sorbent for efficient removal of RH in fixed-bed adsorption column. [ABSTRACT FROM AUTHOR]

This method shows a novel, fast, and simple magnetic solid-phase extraction (SPE) and spectrophotometric procedure for preconcentration and determination of ranitidine hydrochloride in human plasma and aquatic samples by using Fe3O4 nanoparticles (NPs) modified by sodium dodecyl sulfate (SDS) as an extractor. The unique properties of Fe3O4 NPs including high surface area and strong magnetism were utilized effectively in the magnetic SPE process. The determination method is based on the SDS-coated Fe3O4 NPs with extracted ranitidine-HCl, which was subsequently monitored spectrophotometrically at λmax = 320 nm. Effects of different parameters influencing the extraction efficiency of ranitidine-HCl including the pH value, amount of SDS, and Fe3O4 NPs, extraction time, desorption solvent, desorption time, and sample volume were optimized. Under optimized conditions, the method was successfully applied to the extraction of ranitidine-HCl from human plasma and aquatic samples. The extraction recovery in human plasma and different matrixes of waters were investigated and values of 89.0%-103.4% were obtained. The calibration graph for the determination of ranitidine-HCl was linear in the range of 0.025-1.50 μg mL−1 with R2 = 0.9946. The limit of detection of the proposed method was 7.5 × 10−3 μg mL−1. The repeatability and reproducibility (relative standard deviation) of the mentioned method were 0.83% and 1.22%, respectively. The experimental results showed that the proposed method was feasible for the analysis of ranitidine-HCl in environmental and biological samples. [ABSTRACT FROM AUTHOR]

Understanding the characteristics of crystal polymorphism of active pharmaceutical ingredients and analyzing them with high sensitivity is important for quality of drug products, appropriate characterization strategies, and appropriate screening and selection processes. However, there are few methods to measure intra- and intermolecular correlations in crystals other than X-ray crystallography, for which it is sometimes difficult to obtain suitable single crystals. Recently, solid-state NMR has been recognized as a straightforward method for measuring molecular correlations. In this study, we selected ranitidine hydrochloride, which is known to exist in two forms, 1 and 2, as the model drug and investigated each form using solid-state NMR. In conducting the analysis, rotating the sample tube, which had a 1-mm inner diameter, increased the solid-state NMR resolution at 70 kHz. The 1 H- 14 N dipolar-based heteronuclear multiple quantum coherence (D-HMQC) analysis revealed the intermolecular correlation of Form 1 between the N atom of the nitro group and a proton of the furan moiety, which were closer than those of the intramolecular correlation reported using single X-ray crystal analysis. Thus, 1 H- 14 N D-HMQC analysis could be useful for characterizing intermolecular interaction in ranitidine hydrochloride crystals. In addition, we reassigned the 13 C solid-state NMR signals of ranitidine hydrochloride according to the liquid-state and multiple solid-state NMR experiments.

In the present communication, we report the activities and activity coefficients of a model drug, ranitidine hydrochloride (RT·HCl) in aqueous solutions at 298.15 K. These calculations are based on the experimental measurements of densities and osmotic coefficients of RT·HCl in aqueous solutions as a function of concentration of the drug at 298.15 K. The density data have been used to obtain apparent and partial molar volumes at finite concentrations as well at infinite dilution and the experimental osmotic coefficient data are used to determine the activity and mean ionic activity coefficients of solute and solvent, respectively. The activity data have been processed to obtain the mixing and excess Gibbs energy changes as well as to obtain the osmotic pressure and osmotic virial coefficient of the drug. The variation of osmotic coefficient ( ϕ) and ln γ as functions of concentration are studied; we observed a negative deviation from the limiting law in solution. The values of critical micelle concentration (cmc) and aggregation number ( n) are estimated by applying the pseudo-phase separation model to the ϕ data. The data have been examined by applying the McMillan-Mayer theory of solutions and Pitzer approach for aqueous ionic solutions. The results are interpreted in terms of hydrophobic stacking interactions, structure making/breaking effects (kosmotropic/chaotropic effects) and cation-cation, cation-anion-cation attractions in aqueous solutions. [ABSTRACT FROM AUTHOR]