Effect of Cobalt and Chromium Ions on the Chlorhexidine Digluconate as Seen by Intermolecular Diffusion

Metal ions such as cobalt (II) and chromium (III) might be present in the oral cavity, as a consequence of the corrosion of Co-Cr dental alloys. The diffusion of such metal ions into the organism, carried by saliva, can cause health problems as a consequence of their toxicity, enhanced by a cumulative effect in the body. The effect of the chlorhexidine digluconate, which is commonly used in mouthwash formulations, on the transport of these salts is evaluated in this paper by using the Taylor dispersion technique, which will allow an assessment of how the presence of chlorhexidine digluconate (either in aqueous solution or in a commercial formulation) may affect the diffusion of metal ions. The ternary mutual diffusion coefficients of metal ions (Co and Cr) in the presence of chlorhexidine digluconate, in an artificial saliva media, were measured. Significant coupled diffusion of CoCl2 (and CrCl3) and chlorhexidine digluconate is observed by analysis of the non-zero values of the cross-diffusion coefficients, D12 and D21. The observed interactions between metal ions and chlorhexidine digluconate suggest that the latter might be considered as an advantageous therapeutic agent, once they contribute to the reduction of the concentration of those ions inside the mouth.

Development of Lipid-Based Gastroretentive Delivery System for Gentian Extract by Double Emulsion–Melt Dispersion Technique

Gentian (Gentiana lutea L., Gentianaceae) root extract (GRE) is used for the treatment of gastrointestinal disorders. However, its bioactive potential is limited in conventional forms due to the low bioavailability and short elimination half-life of the dominant bioactive compound, gentiopicroside. The aim of study was to encapsulate GRE in the lipid-based gastroretentive delivery system that could provide high yield and encapsulation efficiency, as well as the biphasic release of gentiopicroside from the tablets obtained by direct compression. Solid lipid microparticles (SLM) loaded with GRE were prepared by freeze-drying double (W/O/W) emulsions, which were obtained by a multiple emulsion–melt dispersion technique, with GRE as the inner water phase, Gelucire® 39/01 or 43/01, as lipid components, with or without the addition of porous silica (Sylysia® 350) in the outer water phase. Formulated SLM powders were examined by SEM and mercury intrusion porosimetry, as well as by determination of yield, encapsulation efficiency, and flow properties. Furthermore, in vitro dissolution of gentiopicroside, the size of the dispersed systems, mechanical properties, and mucoadhesion of tablets obtained by direct compression were investigated. The results have revealed that SLM with the macroporous structure were formulated, and, consequently, the powders floated immediately in the acidic medium. Formulation with porous silica (Sylysia® 350) and Gelucire® 43/01 as a solid lipid was characterized with the high yield end encapsulation efficiency. Furthermore, the mucoadhesive properties of tablets obtained by direct compression of that formulation, as well as the biphasic release of gentiopicroside, presence of nanoassociates in dissolution medium, and optimal mechanical properties indicated that a promising lipid-based gastroretentive system for GRE was developed.

Enteric methane emission estimates for Kenyan cattle in a nighttime enclosure using a backward Lagrangian Stochastic dispersion technique

This study provides methane (CH4) emission estimates for mature female African beef cattle in a semi-arid region in Southern Kenya using open-path laser spectroscopy together with a backward Lagrangian Stochastic (bLS) dispersion modeling technique. We deployed two open-path lasers to determine 10-min averages of line-integrated CH4 measurements upwind and downwind of fenced enclosures (so-called bomas: a location where the cattle are gathered at night) during 14 nights in September/October 2019. The measurements were filtered for wind direction deviations and friction velocity before the model was applied. We compared the obtained emission factors (EFs) with the Intergovernmental Panel on Climate Change (IPCC) Tier 1 estimates for the Sub-Saharan African (SSA) countries, which were mostly derived from studies carried out in developed countries and adapted to the conditions in Africa. The resulting EF of 75.4 ± 15.99 kg year−1 and the EFs calculated from other studies carried out in Africa indicate the need for the further development of region-specific EFs depending on animal breed, livestock systems, feed quantity, and composition to improve the IPCC Tier 1 estimates.

Solubility enhancement of glipizide and development of its fast-dissolving oral film

Background: Difficulty in swallowing tablet dosage form is common among all ages people, especially old and pediatrics. Fast dissolving oral films (FDOFs) may represent an innovative dosage type that settles the issue of gulping and supply fast onset of action. Objective: The objective of the present investigation was to increase the solubility of poorly soluble Glipizide (BCS Class II) by solid dispersion technique and develop its FDOFs. Methods: A solvent evaporation process was used to make a solid dispersion of the Glipizide. The saturation solubility of glipizide and its solid dispersion was determined in a different solvent. For the film preparation, solvent casting method was chosen. The excipients were selected based on pre-formulation data. The composition of the film was optimized based on a trial-and-error basis using different concentrations of plasticizer. The average weight, thickness, disintegration time, tensile strength, surface pH, folding endurance, drug content, and in-vitro dissolution analysis of the films were all taken into consideration. Results: There was no incompatibility between drug / solid dispersion and the excipients. The solid dispersion of the glipizide showed improved solubility by almost 10 folds. Many of the formulated films disintegrated in less than 30 seconds. At the end of 5 minutes, the optimized film had released more than 90% of the compound. The prepared films were found to be stable at room temperature. Conclusion: The solubility of Glipizide was improved successfully by solubilization technique using soluplus. The FDOFs of the glipizide were successfully formulated using pullulan as polymer.

Enhancement of Solubility Ibuprofen by Solid Dispersion Technique on Natural Mucilage

In this study generally solid dispersions (SDs) of ibuprofen were prepared by for all intents and purposes melt dispersion technique using natural mucilage of Lemon seed as carrier, which really is quite significant. Physical mixtures (PMs) of ibuprofen literally were also prepared with the same carrier and in the same drug-carrier ratio (1:0.5, 1:1 and 1:1.5) to compare the dissolution profile, which generally is fairly significant. The solid dispersions and kind of physical mixtures for all intents and purposes were investigated for drug loading, saturation solubility and dissolution behavior in a subtle way. Saturation solubility study really actually was basically carried out in phosphate buffer (pH 7.4), 0.1 N HCL solution and distilled water, which kind of literally is quite significant. Solid dispersions for all intents and purposes particularly were mostly really found definitely fairly effective to literally kind of enhance the solubility of ibuprofen significantly in all the media, which actually is quite significant. Dissolution test specifically was mostly carried out in two different media, phosphate buffer (pH 7.4) and 0.1 N HCL. Solid dispersion containing Lemon seed mucilage at the ratio of 1:1.5 (drug: carrier) basically showed faster and sort of definitely higher drug release and basically was specifically really found to for the most part actually be most sort of effective among all the very actually solid dispersions in a generally big way, which kind of is fairly significant. Drug carrier interactions specifically specifically were studied by comparing Fourier definitely mostly Transform generally Infrared Spectroscopy (FT-IR) of particularly solid dispersions with pure drug which essentially revealed that the SDs specifically were kind of really stable in a pretty big way, which is fairly significant. So, fairly very solid dispersion may particularly be an definitely really effective technique to specifically enhance dissolution rate of ibuprofen, which kind of literally is fairly significant in a fairly big way.

Bioavailability Enhancement of Ritonavir by Solid Dispersion Technique

Ritonavir is an antiretroviral agent used in the treatment of HIV-infection. It is a BCS class IV drug having poor aqueous solubility leading to poor bioavailability. Bioavailability is the amount of drug that enters the systemic circulation. The bioavailability is affected by various factors like solubility, dissolution and stability. In order to improve bioavailability, many techniques like solid dispersions, nanoparticles, liposomes, encapsulation methods were present. The main aim of this study is to improve the bioavailability of ritonavir with the help of Polyvinyl Pyrrolidone (PVP) K-30 by using solid dispersion technique. Different formulations were made with varied concentrations of polymer. Characterization of solid dispersion was done by phase solubility, drug content, Fourier transformed infrared spectroscopy (FT-IR), Differential Scanning Calorimetry (DSC) and in-vitro dissolution studies. From phase solubility studies that apparent solubility constant was found to be 42.227M-1. The drug content of the binary system of ritonavir and PVP was found to be ranging from 99.17% to 103.06%. %. FT-IR studies revealed that there was no drastic change in the wave number indicating polymer compatibility with drug. In-vitro dissolution studies proved that there was an increase in drug release of ritonavir with incremental ratios of polymer and F5 formulation has shown almost 95% of drug release. Keywords: Bioavailability, Solid dispersion, Polyvinyl pyrrolidine, Solvent evaporation, Dissolution.

ROLE OF FUNCTIONALIZED GUAR GUM IN SOLID DISPERSION OF NON-STEOIDAL ANTI-INFLAMMATORY DRUG

The current investigation was developed to study the role of functionalized guar gum as carrier in solid dispersion of iboprofen. The solid dispersion technique using aminated guar gum would be an effective approach for increasing the solubility and increasing dissolution behaviour of ill fathomable medicament than the native guar gum. The results of FTIR and DSC studies confirmed that there is no chemical interaction or no incompatability between the drug and excipients. The invitro dissolution study was performed for the the prepared formulations. Based on the results SD3 was shown highest drug release 99.41% within 24hrs. Stabiliy study was conducted as per ICH guidelines and the falloutsrevealed that there is no physical or chemical change.it may be concluded that solubility of ibuprofen can br improved by using functionalized guar gum in the solid dispersion, which provides a wide scope for the therapeutic efficiency.

Dependence of Viscosity and Diffusion on β-Cyclodextrin and Chloroquine Diphosphate Interactions

Mutual diffusion coefficients of chloroquine diphosphate (CDP) in aqueous solutions both without and with β-cyclodextrin (β-CD) were measured at concentrations from (0.0000 to 0.0100) mol dm−3 and 298.15 K, using the Taylor dispersion technique. Ternary mutual diffusion coefficients (Dik) measured by the same technique are reported for aqueous CDP + β-CD solutions at 298.15 K. The presence of β CD led to relevant changes in the diffusion process, as showed by nonzero values of the cross-diffusion coefficients, D12 and D21. β-CD concentration gradients produced significant co-current coupled flows of CDP. In addition, the effects of β-CD on the transport of CDP are assessed by comparing the binary diffusion coefficient of aqueous CDP solutions with the main diffusion coefficient (D11) measured for ternary {CDP(1) + β-CD(2)} solutions. These observations are supported by viscosity analysis. All data allow to have a better interpretation on the effect of cyclodextrin on the transport behavior of CDP.

Characterization and in-vivo toxicological evaluation of imidacloprid nanoemulsion in rats

Acute pesticide poisoning is an important public health problem worldwide and accounts for a significant number of deaths occurring each year. The present article aimed to investigate toxic effects of imidacloprid (IMD) nanoemulsion formulated using ultrasound dispersion technique, and characterized using FTIR, TEM anddynamic light scattering in adult rats. The synthesized Nano-emulsion droplets are mainly spherical in shape and their sizes ranged between (19nm –128 nm) with zeta potential of −38.8± 0.mV. Also, The median lethal dose (LD50) of nano imidacloprid in rats was 39 mg/kg body weight. Administration of different doses of 3, 1.4 and 0.8 mg.kg mg/kg b.wt. of IMD Nano emulsion to rats for 21 days, adversely affects the body weight and weight gain, and resulted in a significant increase in serum serum ALT, AST activities , glucose, Creatinine, urea and cholesterol concentrations, as well as reduced serum total proteins, Albumin and globulin as compared to control rats. The results clearly suggest that treatment with IMD nanoemulsion adversely affects the liver & kidney functions which confirmed by the histopathological findings. Nanoemulsion form and also increases the DNA damage as confirmed by the comet test

Solubility and Dissolution Enhancement of Ebastine by Surface Solid Dispersion Technique

Ebastine (EBS) is a non-sedating antihistamine with a long duration of action. This drug has predominantly hydrophobic property causing a low solubility and low bioavailability. Surface solid dispersions (SSD) is an effective technique for improving the solubility and dissolution rate of poorly soluble drugs by using hydrophilic water insoluble carriers. The present study aims to enhance the solubility and dissolution rate of EBS by using surface solid dispersion technique. Avicel® PH101, Avicel® PH 102, croscarmellose sodium(CCS) and sodium starch glycolate(SSG) were used as water insoluble hydrophilic carriers. The SSD formulations of EBS were prepared by the solvent evaporation method in different drug: carrier weight ratios and evaluated for their percentage yield, drug content , water solubility, dissolution study in 0.1 N HCl, crystal lattice using powder X-ray diffraction (PXRD) and Fourier Transform Infrared Spectroscopy (FTIR) for determination the drug-carrier interaction. Most of the prepared SSD formulas showed improvement of drug solubility. The best result was obtained with formula SSD16 (EBS:CCS 1:15) that showed high percentage yield (98.5%), high drug content (98.39%) and 8.2 fold increase in solubility compared to solubility of pure drug with improved dissolution rate. The drug was converted to amorphous form without chemical interaction with the carrier.