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Background: Currently, many natural gums are extensively utilized as suspending agents in the formulation of pharmaceutical suspensions. They are easily available, nontoxic, biodegradable, and cost‐effective to be used as pharmaceutical excipients. Objective: The present study was aimed at physicochemical characterization and evaluation of the suspending capacity of Boswellia papyrifera gum (BPG) in comparison with sodium carboxy methyl cellulose (SCMC) and tragacanth gum (TG). Methods: The extracted and powdered BPG was subjected to physicochemical properties such as micromeritics, solubility, swelling power, ash value, moisture content, conductivity, pH, and apparent viscosity using standard methods. Metronidazole benzoate suspensions were formulated using various concentrations of BPG, SCMC, and TG (1%–5% w/v). The apparent viscosity, flow rate, sedimentation volume, redispersibility number, pH, and drug content were studied as assessment parameters. Results: The micromeritic studies revealed that BPG exhibited good flow properties. There was also a significant increase in solubility and swelling power of the gum as a function of temperature. The gum had 2.78% ash value and 4.32% moisture content. Conductivity and apparent viscosity of the gum were found to be increased with concentration (p < 0.05). However, the apparent viscosity of BPG was decreased with shear rate (p < 0.05), rendering a pseudoplastic flow property of the gum, which is an ideal characteristic of suspending agents. The suspending capacity of the BPG was found to be comparable to SCMC, but higher than TG. Thus, it can be concluded that BPG could be used as the best alternative to natural and synthetic suspending agents. [ABSTRACT FROM AUTHOR]

The transportation of coal-based solid waste filling slurry (CSWFS) through pipelines for underground goaf injection is essential for enhancing mine safety and promoting green, low-carbon coal mining. To address the issue of pipeline blockage caused by the suspension sensitivity of CSWFS during long-distance transportation, this study proposes the addition of the suspending agent hydroxypropyl methyl cellulose (HPMC) to transform the filling slurry into a stable suspending slurry. The mechanism by which the suspending agent modifies the rheological property of CSWFS was elucidated and verified. Firstly, an evaluation index system for the suspending state of CSWFS based on the "experimental test and theoretical calculation" was established. The values for layering degree, bleeding rate time-loss, and the corresponding average time-loss rate over 0 to 120 min of A1–A5 CSWFS were recorded as 24 mm–2 mm, 3.0–0.2%, 252.4–54.2%, and 149.6–14.6%, respectively. The concentration gradient evaluation result, C/CA = 0.91 (≥0.8), confirmed that the suspending agent maintained a stable suspending state over time for CSWFS. Secondly, it was demonstrated that the suspending agent HPMC modified the rheological property of A1–A5 CSWFS by increasing its plastic viscosity, which strengthened the viscous resistance to particle settling, thereby transforming a semi-stable slurry into a stable one. Additionally, the formation of a spatial suspending network by the suspending agent ensures that no pipeline blockage accidents occured in practical engineering applications. Furthermore, the XRD and SEM tests were utilized to verify the microstructure of the top (T) and bottom (B) samples in A4 block. It was concluded that the type of hydration products, occurrence forms, lapping compactness, and microstructural development were consistent, ultimately forming a high-strength, dense, hardened filling block. Finally, numerical simulation confirmed that the addition of suspending agent in A4 slurry formed a comprehensive spatial suspending network and a well-structured, unified system. This is one effective approach which could contribute to addressing the technical issue of pipeline blockage during long-distance pipeline transportation. [ABSTRACT FROM AUTHOR]

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The solubility is the preferential criteria for the medicament to show pharmacological action. A pharmaceutical suspension is a coarse dispersion of insoluble solid particle in a liquid medium. One of the best suitable dosage forms for people who cannot take solid dosage forms. It contain solvents, buffering agent, preservative, antioxidants, wetting agent, anti-foaming agent, suspending agent and flavouring agent. Suspension dosage form incorporate effective distribution of lipophilic drug; mask a bitter taste, avoid the use of cosolvents and provide resistance to deterioration of drug due to hydrolysis, oxidation or microbial activity. In addition, nanosuspension is the novel and recent advancement in enhancing aqueous solubility of weakly soluble drugs. It not only increases aqueous solubility but increases bioavailability as well. As a result of the significant improvement in bioavailability, the flexibility for surface modification and mucoadhesion for drug targeting have significantly expanded the scope of this novel formulation technology. Suspension allows for the absorption drug relatively higher than any other solution dosage forms. Different method of preparation are used with a solvent, suspending agent (HPMC and Methyl Cellulose) and Surfactant (Tween-80, and SLS). Introduction, preparation techniques, characterisation, and applications of the nano suspension are covered in this review article. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this work is to assess the suitability of Parkia biglobosa mucilage (PBM) as a suspending agent in metronidazole suspension. Methods and Materials: Metronidazole suspension was formulated with mucilage (0.1%, 0.5%, 1%, and 2% w/v) from P biglobosa seeds as the suspending agent. Similar suspensions of metronidazole that contained (0.1%, 0.5%, 1%, and 2% w/v) tragacanth or gelatin were also prepared for comparison to PBM-based formulations. The suspensions were assessed for rheological properties, sedimentation volume, degree of flocculation, ease of redispersion, flow rate (flowability), and drug-excipient compatibility using Fourier-transform infrared spectroscopy. Results: Brownish metronidazole suspensions with a smooth and elegant appearance were obtained. After 2 weeks of storage at ambient temperature (28 ± 2°C), the ease of redispersion was in the following order: tragacanth < PBM < gelatin-containing formulations. The optimal pH of the formulation was slightly acidic and did not significantly change (p > 0.05) after 3 months of storage at ambient temperature (28 ± 2°C). However, the viscosity of the formulations was reduced by more than 30%, and the flow rate was significantly increased (P < 0.05). Suspensions formulated with 2% PBM were well-flocculated and easily redispersible. Furthermore, the sedimentation volume and sedimentation rate of suspensions formulated with 2% PBM were comparable to that of tragacanth- and gelatin-containing suspensions. Conclusion: PBM hence has great promise as a suspending agent for pharmaceutical preparations. [ABSTRACT FROM AUTHOR]

Suspensions are two phase systems composed of solid materials dispersed in liquid. Detarium microcarpum gum (DMG) was obtained by acetone precipitation of filtrate obtained from maceration of Detarium microcarpum seed powder using distilled water. Ibuprofen was pulverized using a mortar and dispersed in distilled water to form ibuprofen suspension formulation (IS1). Five other ibuprofen suspension formulations were prepared using either DMG or acacia as the suspending agent (IS2-IS6). Benzoic acid was added during the preparation of formulations IS4 and IS6 as preservative. Physicochemical properties like pH, viscosity and the total microbial count for the suspensions were evaluated. Drug-excipient compatibility was studied using FTIR spectroscopy. The pH of the suspensions ranged from 3.7±0.0 -5.3±0.0 on day 0 to 3.9±0.0 - 6.3±0.0 on day 35. Flow rate was from 2.21±0.13 - 33.00±3.70 mls-1 on day 0 to 1.88±0.12 - 20.19±0.16 mls-1 on day 35. The viscosity at 25oC ranged from 2391.3 - 5702.2 mPas on day 0 to 3793.0 - 3828.2 mPas on day 35. It was a shear thinning system. Formulation IS6 was the most stable and IS1 was the least stable. The suspensions contained high level of bacteria on day 0 which increased significantly on day 35, with exception of formulations IS4 and IS6. Ibuprofen suspensions with good physicochemical properties were produced using DMG but the level of microbial contamination observed highlighted the need of having good environmental hygiene and use of preservatives when natural gums are used in formulations. [ABSTRACT FROM AUTHOR]

The aim of the article was to obtain maximum information about plant mucilage, its sources and applications in the pharmaceutical industry. This study focuses on the scientific articles and books available in Internet resources and college library that deal with the sources, applications, extraction and isolation of plant mucilage. Mucilage is obtained mainly from plant sources and can be isolated easily. Due to the low cost, easy availability, non-toxicity, non-irritancy, and biocompatibility, mucilage is of great demand in the field of pharmaceuticals. Hibiscus rosa-sinensis L., Trigonella foenum-graecum L., Abelmoschus esculentus L, Plantago ovata Forssk. and Aloe barbadensis L. are some common sources of mucilage. The isolation methods vary depending on the part of the plant where mucilage is present. It is commonly used as gelling agent, suspending agent, binder, and disintegrant. Since it is hydrophilic in nature, chances of deterioration are higher. In this review, different mucilage sources and their isolation methods are discussed in detail. Mucilage is used as excipient in many formulations of tablets, suspensions, gels, etc. The study explores the potential of plant mucilage as an excipient in pharmaceutical formulations. The biodegradable and biocompatible properties of this inexpensive excipient make it more favourable for the newer formulation development.

The objective of this investigation is to formulate reconstitutable indomethacin oral suspension as indomethacin dry syrup with co-processed composite of Zea mays husk cellulose and sodium carboxymethylcellulose for evaluation in indomethacin delivery. Pre-formulation studies were carried out on the Zea mays husk cellulose. Compatibility studies were carried out for the Zea mays husk cellulose and indomethacin. Dry syrup was formulated with composites of Avicel CE 15, Avicel HF E-102, Zea mays husk cellulose, and starch respectively in sodium carboxymethylcellulose. The dry syrups were reconstituted to suspension, and evaluated. The pre-formulation properties were within limits. FTIR result of Zea mays husk cellulose showed purity of cellulose. FTIR spectroscopy of Zea mays husk cellulose and indomethacin showed no interaction of cellulose with indomethacin. The release of indomethacin from reconstituted suspensions followed apparent (pseudo) first order kinetics, indicative of no reservoir entrapment, complexation, nor encapsulation of the active drug. With re-dispersion number of 3.47 ± 0.47, the re-dispersion of the reconstituted suspension, and other rheological properties were significantly (p < 0.5) improved by the Zea mays husk cellulose - sodium carboxymethylcellulose composite. It was found that Zea mays husk cellulose - sodium carboxymethylcellulose composite can substitute the standard suspending agent in formulation of reconstitutable indomethacin suspension based on its improved rheological, suspending and thixotropic properties. [ABSTRACT FROM AUTHOR]

In order to prepare detergents with high suspension ability, low viscosity, high transparency and low film-forming ability, two monomers of ethyl acrylate and methacrylic acid were used to prepare the polymer as the suspending agent in detergent (experimental group A). The influence of different monomer ratios on the suspension ability of the suspension agent was investigated. The viscosity and turbidity, suspension ability, film-forming ability and shear thinning ability in detergent of the experimental group A was compared with two commonly used acrylic suspension agents, namely Carbopol® Aqua SF-1 Polymer (control group B) and Carbopol® Aqua SF-2CN Polymer (control group C). The results show that the ductility in application of the experimental group A is the best due to the smallest viscosity in the same experimental conditions. When the mass fraction of the suspending agent is ≥1.8%, all three suspending agents have good transparency and suspending ability. The film forming ability of the experimental group A is the worst, therefore it is not easy to block the pump head. The spray extrusion strength and spray uniformity of the experimental group A are better than those of the control group B and the control group C. Overall, the performances of the experimental group A are the best. [ABSTRACT FROM AUTHOR]

The properties of modified starch derived from Pennisetum glaucum (PT) seed as a suspending agent in metronidazole benzoate suspension was evaluated. Matured PT seeds were steeped for 72h, wet milled and the slurry washed with water through a muslin cloth to obtain native PT starch (NPS) which was dried at 60°C. NPS slurry was heated (70°C), cooled (40°C), and submerged in 3.5%w/v sodium hypochlorite for 10 min, washed with 95%v/v alcohol till neutral to litmus. The modified starch (MPS) was dried (50°C), classified (180µm). NPS and MPS were characterized using standard methods. Metronidazole benzoate (MTBZ) suspensions were formulated using 2.5%w/v, 5.0%w/v and 7.5%w/v of MPS as suspending agent. Similar concentrations of acacia and methylcellulose were used as standard. An MTBZ suspension without polymer served as control. The suspensions were evaluated for pH, sedimentation, flow rate, viscosity and re-dispersibility within 28 days. Results show that modification enhanced the densities, compressibility, hydration capacity and swelling index of MPS. The suspensions had stable pH and viscosities. Sedimentation volume increased with increase in concentration of polymer (MPS>Methylcellulose>acacia>control) while flow rate decreased with increased polymer concentrations. The MTBZ suspensions were re-dispersed on agitation. MPS formed more stable suspensions than acacia and methylcellulose at similar concentrations. [ABSTRACT FROM AUTHOR]

The morphology and encapsulation efficiency of thermoregulating microcapsules based on a spreading coefficient theory and polar surface energy component were evaluated. For this purpose the microencapsulation of phase change materials (PCMs) with different copolymer shells and using different suspending agents by the suspension-like polymerization technique has been carried out. Contact angles and interfacial tensions were measured, and results were discussed with respect to the internal structure as well as encapsulation efficiency of the microcapsules. A core/shell structure was expected as the equilibrium morphology, whereas the experimental structure exhibited a matrix morphology. A core-shell structure was favored by increasing the polarity of the polymer and decreasing the solubility between the core and shell. The type and amount of suspending agent do not have a significant influence on the final characteristic of the microcapsules. Shells with various polarities were synthesized from styrene (S), divinylbenzene (DVB) and hexa(methacryloylethylenedioxy)cyclotriphosphazene (PNC-HEMA), and it was found that a core-shell structure was only obtained for microcapsules with a high polar surface energy component. [ABSTRACT FROM AUTHOR]

The adsorption of polyvinylpyrrolidone (PVP) by the thermoregulating microcapsules has been studied. The mass ratio of PVP has been changed from 1 to 20, with respect to the lowest amount of PVP value (4.08 g). The results confirmed that a large amount of PVP was adsorbed by the polymeric shell. Experimental data were perfectly fitted by Langmuir model, obtaining at a confidence level of 95% values of 192.9 ± 0.4 g/kg and 0.18 ± 0.11 m/kg for the maximum adsorption capacity and the equilibrium constant, respectively. It was found that utilizing PVP, at a concentration of 5.03 wt% of the total mass provided optimum conditions for synthesizing thermoregulating microcapsules containing Rubitherm®RT27 from poly(styrene-divinylbenzene) (P(St-DVB)), with the best thermal and physical properties. Finally, the robustness of the process was checked at a large scale by using a reactor that maintains geometrical similarities with that used at laboratory scale. The thermal properties, the encapsulation efficiency, and the microcapsule yield were similar, but at pilot plant scale, narrower particle size distributions were obtained. [ABSTRACT FROM AUTHOR]

The present study was undertaken to evaluate the mucilage isolated from Spinacia oleracea L. leaves, commonly named spinach (family: Amaranthaceae) as an innovative suspending agent. Zinc oxide suspensions (20% w/v) were prepared using the mucilage of S. oleracea L. leaves as a suspending agent, and it was evaluated for its stability by using parameters like, sedimentation profile, degree of flocculation, and redispersibility. The effect of the tested mucilage on the suspension was compared with various commonly used suspending agents, such as, tragacanth, bentonite, and sodium carboxymethyl cellulose (NaCMC) at concentrations of 0.5, 1.0, and 2.0% w/v. The results obtained indicated that the mucilage of S. oleracea L. leaves could be used as a suspending agent, and the performance was found to be superior to both tragacanth and bentonite.

Due to the physicochemical properties of jackfruit (JK) seed starch, it is interesting to use jackfruit mucilage for cosmetic application. The aim of this study was to investigate the physical properties and the effectiveness of JK mucilage at the range of 1 to 5% w/v for using as suspending agent and emulsifying agent. It was found that the pH of 3% w/v JK mucilage was 4.63±0.11. At the concentrations lower than 3% w/v the mucilage exhibited newtonian flow whereas at higher concentration the mucilage showed pseudoplastic with thixotropic flow. As increased the concentration of JK mucilage, the surface tension of purified water was reduced to the range of 1.77-3.8 mN/m and the interfacial tension between water and mineral oil was reduced to the range of 9.07-12.43 mN/m. The viscosity of the mucilage was reduced dramatically in acid pH but in salt solution at the concentrations lower than 2% w/v, the viscosity was increased. In addition, the JK mucilage was able to flocculate Titanium dioxide. Even though the JK mucilage was able to thicken the external phase of emulsion, it exhibited as a poor emulsifier. The JK mucilage, therefore, has the potential for use as a suspending agent and thickening agent in cosmetic products.

The purpose of this study is to evaluate the use of arabinoxylan as potential suspending agent, an effective alternative to commercially used excipients for the preparation of pharmaceutical suspensions. Alkali extraction was done to separate arabinoxylan from ispaghula (Plantago ovata) seed husk by alkali extraction its physicochemical characterization was done and the suspending properties of arabinoxylan isolated were evaluated comparatively with those of bentonite at different concentration ranges of 0.125,0.25,0.5 and 1% in Zinc oxide suspension. The parameters employed for evaluation were sedimentation volume, degree of flocculation, flow rate, density, pH, redispersibility, microbiological evaluation and particle size analysis. Physicochemical characterization of arabinoxylan indicates its suitability as excipient as it has fair flow properties, low moisture content and almost neutral pH. Arabinoxylan at low cone. 0.125% showed sedimentation volume comparable to commercially used suspending agents such as bentonite 1% while suspensions containing higher concentrations such as 0.25% (sedimentation volume 92%), 0.5% (sedimentation volume 94%) and 1% cone, (sedimentation volume 98%) of arabinoxylan remained almost completely suspended during study period of 7 days. Formulations containing 0.125% and 0.25% arabinoxylan as suspending agents are easily redispersible as compared to bentonite containing formulation while formulation containing 0.5% arabinoxylan are moderately redispersible while formulation containing 1% suspending agent gel upon storage and was not redispersible. Furthermore arabinoxylan produces stable, highly flocculated suspension, which fulfilled microbiological, and particle size specifications, however the formulations containing higher arabinoxylan 1% concentration gel upon storage. So it is concluded that arabinoxylan could be used as effective suspending agent at low concentrations in Zinc oxide suspension. [ABSTRACT FROM AUTHOR]

Introduction: Present work, is an effort toward exploring the potential of Cassia fistula Linn. seed gum as an extended release polymer and laxative. While, C. fistula pulp polymer has evaluated as suspending agent. Materials and Methods: For extended release application, total five batches (F1-F5) were prepared by varying the ratio of drug:polymer as 1:1, 1:2, 1:3, 1:4, and 1:5, respectively. The granules were prepared by wet granulation method and further evaluated for micromeritic properties such as angle of repose (θ), Carr's compressibility index (CCI), and Hausner's ratio. Further compacts were evaluated by hardness, thickness, swelling index, in-vitro dissolution, and so on. Laxative activity was evaluated by administration of seed polymer (100 mg/kg) alone or in combination with bisacodyl (2.5 mg/kg) in 1% Tween 80. Zinc oxide suspension was prepared by varying the concentration of C. fistula pulp polymer and compared with suspension made by use of tragacanth, sodium carboxymethyl cellulose and bentonite. Results: Result showed that granules were free flowing, while the compact extended the drug release up to 10 h (72.84 ± 0.98; batch F5) and followed Higuchi matrix release kinetics. This extended release might be due to the formation of polyelectrolyte complex because of gluco-mannose in seed gum. Result of in-vivo laxative activity showed that seed polymer reduced faeces weight after 24 h compared to control (P < 0.01). Conclusions: Pulp polymer showed good sedimentation volume, but alone fails to stabilize the suspension for a longer period, so it could be useful in combination with other suspending agents and can be useful as novel excipient. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the suspending properties of the co-precipitate from Irvingia gabonensis gum variety Excelsa (Fam: Irvingiaceae) and gelatin. Methods: The gum from Irvingia gabonensis was extracted and co-precipitated with gelatin in gum/gelatin ratios of 1:1, 1:2, 1:3, 1:4, 1:0 and 0:1. The suspending ability of the different ratios was evaluated in magnesium trisilicate suspension, and compared with a suspension prepared with Compound Tragacanth Powder BP (CTP) as well as a commercially available magnesium trisilicate suspension (MTS). The parameters tested were sedimentation rate, flow rate, viscosity, and pH. The effect of mono- and divalent electrolytes on the sedimentation rate of the suspensions was also studied. Results: In terms of suspending ability, co-precipitated gum-gelatin ratio of 1:2 was comparable to CTP while gum-gelatin ratio 1:3 was a superior suspending agent than CTP with regard to the parameters determined. At 2 % w/v concentration, the suspending ability of the suspending agents were in the rank order: 1:4 > 1:3 > 1:2 > CTP > 1:1 > 1:0 > MTS > 0:1. The 1:3 ratio suspensions also exhibited good stability following addition of mono- and divalent electrolytes although there was significant (p > 0.05) reduction in sedimentation volume. Conclusion: It can be inferred from the results of this investigation that the suspension prepared with the co-precipitate of Irvingia gabonensis gum and gelatin as a suspending agent appears to be superior to those prepared with the gum or gelatin alone as well as MTS. [ABSTRACT FROM AUTHOR]

Some excipients are currently available for the formulation of pharmaceutical suspensions. The purpose of this study is to develop cheap and effective natural excipient that can be used as an effective alternative for the formulation of pharmaceutical suspensions. The suspending properties of Opuntia ficus-indica and Opuntia stricta mucilages (family Cactaceae) were evaluated comparatively with that of NaCMC at concentration range of 2-6% (w/v) in Paracetamol suspension. Sedimentation volume (%) (with and without electrolyte), rheology, redispersibility, and dissolution rate of the suspensions were employed as evaluation parameters. The values obtained were used as basis for comparison of the suspending agents. The apparent viscosities of the suspensions in all the suspending agents concentration levels and applied shear rates were in the order of NaCMC>OS>OFI with non-Newtonian flow and accordingly the flow rates of the suspensions were in the order of OFI>OS>NaCMC. The sedimentation volumes (%) of the suspensions in all the suspending agent concentration levels were higher for OS followed by OFI and then NaCMC. The high sedimentation volumes (%) of suspensions, in turn, were accompanied by ease of redispersibility of that order. The effect of electrolyte on sedimentation volume (%) had dual effect. It was only the suspensions that had NaCMC that showed increase in sedimentation volume (%) in all molar NaCl concentration. However, in suspensions that had mucilages of OS and OFI, an initial increase in sediment volumes (%) were accompanied by decrease after 1x10-3M and 1x10-2M of NaCl, respectively. Dissolution of the suspensions which had mucilages attained the acceptable ranges (≥ 80% drug release in 30 min) in 5 min. Similarly, except A6 formulations A2, A3, A4 and A5 have attained the limit but the release was not as quick as the previous formulations. Hence, it can be concluded that mucilages of Opuntia spp. (Opuntia ficus-indica and Opuntia stricta) can be used as alternatives to NaCMC as suspending agent in suspension formulations. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study was to extend the application of pectin extracted from pomelo peel to pharmaceutical suspensions. Particularly, the influence of pectin on the stability of indomethacin suspension was investigated. The use of cation, type and concentration of pectin, pH and temperature influenced the flocculating activity of pectin in suspension. The extracted pectin has comparable activity to commercial pectins. Low concentration of pectin and ferric ions allowed obtaining indomethacin suspensions with adequate properties, i.e., suitable stability and redispersibility. The use of pectin as a suspending agent was achieved with higher concentration; the flocculated, redispersible and stable indomethacin suspension could be produced. The pharmaceutical suspension containing pectin as a flocculating or suspending agent may be applied as liquid drug delivery system for pediatric and geriatric patients. [ABSTRACT FROM AUTHOR]

Grewia gum was extracted from the inner stem bark of Grewia mollis and characterized by several techniques such as gas chromatography (GC), gel permeation chromatography (GPC), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and thermogravimetric analysis of the extracted sample. Spectroscopic techniques such as x-ray photoelectron spectroscopy (XPS), fourier-transformed infrared (FT-IR), solid-state nuclear magnetic resonance (NMR), and 1H and 13C NMR techniques were also used to characterize the gum. The results showed that grewia gum is a typically amorphous polysaccharide gum containing glucose, rhamnose, galactose, arabinose and xylose as neutral sugars. It has an average molecular weight of 5925 kDa expressed as the pullulan equivalent. The gum slowly hydrated in water, dispersing and swelling to form a highly viscous dispersion exhibiting pseudoplastic flow behaviour. The polysaccharide gum is thermally stable and may have application as stabilizer or suspending agent in foods, cosmetics and in pharmaceuticals. It may have application as a binder or sustained-release polymer matrix in tablets or granulations. [ABSTRACT FROM AUTHOR]

An oral controlled release suspension of chlorpheniramine maleate was prepared using ion-exchange resin technology. A strong cation exchange resin Indion 244 was utilized for the sorption of the drug and the drug resinates was evaluated for various physical and chemical parameters. The drug-resinate complex was microencapsulated with a polymer Eudragit RS 100 to further retard the release characteristics. Both the drug-resinate complex and microencapsulated drug resinate were suspended in a palatable aqueous suspension base and were evaluated for controlled release characteristic. Stability study indicated that elevated temperature did not alter the sustained release nature of the dosage form indicating that polymer membrane surrounding the core material remained intact throughout the storage period. [ABSTRACT FROM AUTHOR]

Abstract: Ammonium polymethacrylate (APMA) was used as a suspending agent for the suspension polymerisation of methyl methacrylate. Aqueous APMA solutions were found to exhibit non-Newtonian behaviour. Their high viscosity decreased with increasing pH. Experimental data for drop break up were in agreement with Taylor''s theory of viscous shear break up. It was also found that APMA interferes with the polymerisation kinetics. [Copyright &y& Elsevier]

Three sodium carboxymethyl mungbean starches (SCMMSs) were selected, based on the physicochemical profiles and evaluated as potential pharmaceutical suspending agent in comparison with a sodium carboxymethyl tapioca starch and other five commercial suspending agents. Ibuprofen suspension was employed as a model formulation with 0.5, 1.0, and 2.0% w/v of suspending agents. Evaluation parameters included the determination of sedimentation volume ratio, redispersibility, viscosity and rheological properties and content uniformity studies. The results revealed that a high-viscosity modified mungbean starch, MMS-M-04, possessed suitable properties as a suspending agent and, at 1% concentration, was as effective as sodium carboxymethylcellulose and xanthan gum, two most-commonly used suspending agents. This modified starch could be further developed and employed as a new commercial suspending agent in the pharmaceutical industry. [ABSTRACT FROM AUTHOR]

The synthesis of homo-polymers of acrylic acid and co-polymers of acrylic acid–methyl methacrylate as suspension agents (SA) was performed in aqueous media, and SA were used as stabilizer in the suspension polymerization of styrene. The behavior of water solutions in the interfacial tension of SA against styrene was studied. The composition of the co-polymers and their molecular weights are related to the Zykonski model coefficients and to the molecular configuration of the stabilizer at the interface. It was found that the molecular weight, the composition of SA, the concentration used in the reaction system and the time at which it was added had a marked effect on the stability of the suspension during the reaction and on the final particle size distribution of the polystyrene beads. The homo-polymers of acrylic acid do not prevent correctly the coalescence during the suspension polymerization, while the co-polymers of acrylic acid and methyl methacrylate are well adsorbed into the oil/water interface and then work as good stabilizers for styrene suspension polymerizations. Provided a good stabilizer was used, i.e., with a high molecular weight and enough hydrophobic character, its addition delayed up to the beginning of the sticky stage produced a quite narrow particle size distribution. [ABSTRACT FROM AUTHOR]

Aiming at the problem that the oil well cement slurry is easy to settle and lose its stability under high temperature environment, and combining with the characteristics of traditional cement admixtures "thickening at low temperature and thinning at high temperature", we developed a kind of high-temperature resistant cement suspension agent. A quadripolymer suspension agent P-AN18 was synthesized by free radical polymerization using 2-Acrylamido-2-methylpropane sulfonic acid (AMPS), acrylamide (AM), quaternary ammonium salt monomer N-N octadecyl dimethyl allyl ammonium chloride (DMAAC-18), and high-temperature resistant monomer N-Vinyl-2-Pyrrolidinone (NVP). The synthesis conditions were optimized using the response surface method (RSM) innovatively, the response surface graph (3D) showed the influence of independent variables on the rheological properties and density difference of cement slurry influence. The hydrophobic association structure and high-temperature resistance mechanism of P-AN18 were analyzed by infrared spectroscopy, nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA), nanoparticle size analyzer, fluorescence probe test and scanning electron microscope (SEM) in a freezing environment. The effect of P-AN18 on maintaining the stability of cement slurry system at high temperature was evaluated. The results showed that the polymer suspension P-AN18 has good temperature resistance and compatibility with cement slurry. At 200 ℃, P-AN18 can keep the cement slurry system stable, and the density difference between the upper and lower part of the solidified cement column is less than 0.01 g/cm3. P-AN18 provides a new method for controlling the settlement stability of high-temperature cement slurry, which is expected to be used to improve the safety and cementing quality of deep well cementing. [Display omitted] • Predicting density contrast using RSM model. • Characterizing Polymer suspensions from macro and micro perspectives. • Effective prevention of thermal thinning and particle settling of cement slurry. [ABSTRACT FROM AUTHOR]

Background: Natural polymers have been used in medical, pharmaceutical, cosmetic and food industry. They should be characterized before their possible applications in different industries., Objectives: The objective of this study was to characterize Kheri (Acacia chundra, family: Mimosaceae) gum using analytical, mathematical and pharmaceutical approaches., Material and Methods: Crude Kheri gum (KG) was purified using distilled water as a solvent and ethanol as a precipitating agent. KG was characterized in terms of phytochemical screening, micromeritic properties, microbial load, ash value, rheological behavior, solid state 1H nuclear magnetic resonance (NMR), mass spectra and Fourier-transform infrared spectroscopy (FTIR) studies for their possible applications in food, cosmetics and pharmaceutical industry., Results: Studies show that KG contains carbohydrates, while protein, fat, volatile oils, alkaloids and glycosides are absent. 1% aqueous solution of polysaccharide showed 25.58 × 103 kJ/kg activation energy and 1.39 Reynold's number. Viscosity average molecular weight of purified gum was found 1.73 × 105 D. Thermodynamic parameters, i.e., change in enthalpy ΔHv and change in enthalpy ΔHv, were found to be 12.26 × 103 kJ/mol and 24.47 kJ/mol, respectively. Mathematical approach also determined the rod shaped conformation of KG in aqueous solution. IR spectroscopic study shows the presence of free (COO-) and esterified (COO-R) carboxylic acid, ether (C-O stretching), galacturonic acid and mannose in polysaccharide 1H NMR study predicts presence of tetrahydropyran hydrogen in molecule. Furthermore, KG was also characterized as a suspending agent using paracetamol as a model drug. Flow rate, pH, particle size and settling behavior of suspensions were evaluated. Initial particle size of dispersed phase particles does not change significantly after 45 days., Conclusions: From the findings of the research it can be concluded that KG can be used as an excipient in cosmaceuticals and pharmaceuticals and its characteristic rheological behavior may attract rheologists.

The present study was undertaken to evaluate the mucilage isolated from Spinacia oleracea L. leaves, commonly named spinach (family: Amaranthaceae) as an innovative suspending agent. Zinc oxide suspensions (20% w/v) were prepared using the mucilage of S. oleracea L. leaves as a suspending agent, and it was evaluated for its stability by using parameters like, sedimentation profile, degree of flocculation, and redispersibility. The effect of the tested mucilage on the suspension was compared with various commonly used suspending agents, such as, tragacanth, bentonite, and sodium carboxymethyl cellulose (NaCMC) at concentrations of 0.5, 1.0, and 2.0% w/v. The results obtained indicated that the mucilage of S. oleracea L. leaves could be used as a suspending agent, and the performance was found to be superior to both tragacanth and bentonite.