Dissolution Percentage Research Articles

Formulation of Polyethylene Glycol Based Ibuprofen Nanosuppository Preparations and Assesment of Dissolution

Ibuprofen is widely formulated in oral and rectal dosage forms. Ibuprofen in the rectal route shows c max and t max longer than syrup preparations, this is due to the low solubility of ibuprofen. Nanoparticles are one of the technologies that are widely used to increase the solubility of an active substance. Nanoscale particle size, can increase the solubility of ibuprofen and allow dose reduction. This study aims to formulate ibuprofen nanosuppository preparations, and test the percent dissolution of nanosuppositories compared to conventional suppositories. The ibuprofen nanosuppository formulation consists of ibuprofen lipid component and PEG mix component (PEG 4000: PEG 6000). The ibuprofen lipid component consisted of ibuprofen VCO oil, tween 80 and propylenglycol. This lipid component was then tested for physical characteristics, transmittance, particle size and zeta potential, then the lipid was added to the suppository base component. The responses observed were disintegration time, hardness, and non-intrinsic dissolution efficiency. The test results showed transmittance values of 91.98%, 92.99%, 93.26%. Particle size and potential zeta values of FI = 107, 5 nm, FII 102 nm and FIII 103 nm. The zeta potential were -16.19 mV, -12.44 and -13.25 mV in the lipid component. The test results of the disintegration time of F1, F2, F3 nanosuppositories were 12 minutes, 11 minutes and 10 minutes. The hardness of F1, F2, and F3 were 1.53 kg, 1.43 kg and 1.26 kg and the dissolution efficiency value was higher than conventional suppositories. Modification of ibuprofen nanosuppositories had a significant effect on the percent dissolution of ibuprofen.

Study on the crystallinity of PEG on the crystalline size of flavonoids in a crystalline dispersion system

Poor water solubility and low bioavailability of flavonoids present significant barriers to their development and application. To address these challenges, this study explores the use of crystalline solid dispersions (CSDs) to reduce drug crystalline size and enhance in vivo bioavailability. The CSDs were prepared using a spray-drying technique with chrysin (CHY) and quercetin (QUR) as model drugs and various molecular weights of polyethylene glycol (PEG) as carriers. The authors systematically investigated the factors influencing the interaction between flavonoids and PEG in CSDs. These factors included the relationships between intermolecular interactions and PEG molecular weight, crystallinity, microstructures such as crystalline domain size and crystal morphology of the flavonoids and PEG in CSDs, crystalline size of the drug in CSDs, and in vitro dissolution rate and in vivo pharmacokinetics. Our results indicated that the interaction between flavonoids and PEG in CSDs was influenced more by PEG crystallinity than by its molecular weight. Lower crystallinity of PEG, achieved through recrystallization, led to stronger intermolecular interactions with the drugs. Specifically, PEG8000 exhibited the lowest crystallinity, indicating a higher content of PEG in the amorphous state, which interacted more effectively with the amorphous drug in CSDs. This interaction significantly inhibited drug crystallization growth, resulting in a marked decrease in drug crystalline domain size and crystalline size. Consequently, PEG8000 was identified as the optimal carrier for preparing CSDs, achieving the best cumulative dissolution percentage. The QUR/PEG8000-CSD formulation increased the cumulative dissolution percentage and oral bioavailability of QUR by 18.76 and 20.66 times, respectively, compared to QUR alone. This study demonstrates that PEG crystallinity, following recrystallization, directly affects its intermolecular interactions with the drug, thereby impacting drug crystalline size and dissolution rate.

Dissolution process and mechanism of montmorillonite in oxalic acid and sulfuric acid media at various pH levels

The dissolution of silicate minerals plays a crucial role in many natural geological processes. In order to better comprehend the reaction mechanisms and dissolution characteristics of montmorillonite in different acidic systems, the effects of interfacial reactions of montmorillonite with oxalic and sulfuric acid solutions at various pH levels on the ionic dissolution, crystal structure, and micro-morphology were studied, and the morphology of aluminum and saturation index of secondary mineral were simulated. It was shown that the dissolution amounts of Mg2+, Al3+ and Si4+ in montmorillonite structure decreased with the increase of pH value, which reflected the dependence of montmorillonite dissolution on the pH value of solution. The dissolution percentages of Mg2+, Al3+ and Si4+ after the reaction of montmorillonite with oxalic acid solution were greater than those in sulfuric acid solution, and the highest dissolution rate of Al3+, indicated that both ligands and protons attacked the surface sites of montmorillonite and accelerated the dissolution of ions. Moreover, oxalate ligands exerted specific binding effects on Al3+ ions. While reacting with oxalate and sulfate, the tetrahedral, octahedral and interlayer cations of montmorillonite exhibited the non-stoichiometric and inconsistent dissolution. The oxalate ligands have a strong complexation effect on Al3+, so that Al3+ in oxalate solution exists in the form of aluminum oxalate complex, which reduces the effective concentration of Al3+ in solution and promotes the dissolution of Al3+ in montmorillonite structure. The Mg2+ ions settled at octahedral substitution sites possessed weak stability, while those from the interlayer featured strong interlayer interchangeability, demonstrating the dissolution percentage up to 10.85 % and 8.62 % even in oxalic and sulfuric acid solutions at pH of 6.5. All secondary mineral phases in the solution were undersaturated, making the montmorillonite dissolution difficult to balance. Montmorillonite has a high cation exchange capacity, which makes it have a strong buffer capacity to exogenous acids. This study helps to explain the dissolution process of montmorillonite in inorganic and organic acid solutions at different pH value.

A Study on Formulation and Assessment of Heart Rate Lowering Agent Ivabradine Orally Tablets

This study aimed to develop a method for quantifying the amount of ivabradine in films that are ingested and administered with ease. To do this, a dry granulation technique was applied. The dry granulation process yielded good results when the F5 formulation was mixed with starch, anhydrous lactose, and microcrystalline cellulose PH 102. The strength of the tablet was modified by adding croscarmellose sodium. Sodium starch glycolate was used as the dissolving agent. Purified talc and colloidal silicon dioxide were utilised as glidents. In this mixture, magnesium stearate was employed as a lubricant. Purified talc was used to make tablets stronger and smoother, and titanium dioxide was used to make films opaque. Hydroxypropyl Methyl Cellulose 6 CPS was utilised as a film-forming agent, and polyethylene glycol 6000 was employed as a plasticizer. The manufactured tablet formulations were examined for friability (%), thickness, hardness, and disintegration time in addition to other medicinal properties. It was observed that the drug content was 99.94% and the in-vitro dissolution percentage was measured as 99.89%. Tablets coated with polymer film were manufactured by dry granulation. Ivabradine is administered to persons with coronary artery disease who have normal sinus rhythm and a heart rate more than 72 bpm in order to treat the symptoms of chronic stable angina pectoris. For the symptomatic treatment of stable angina pectorals and symptomatic eternal heart failure, ivabradine is a medication that reduces pulse rate.

Designing starch-based fenofibrate formulations using the melting method

Fenofibrate (FNF) is used to treat hyperlipidemia. However, FNF is a poorly water-soluble drug, and the dosage of commercial products is relatively high at 160 mg in a Lipidil® tablet. Therefore, this study aimed to develop an FNF-solid dispersion (SD) that solubilizes and stabilizes FNF. The melting method that uses the low melting point of FNF was employed. The dissolution percentage of FNF in the optimal formulation (SD2) increased by 1.2-, 1.3-, and 1.3-fold at 5 min compared to that of Lipidil® and increased by 2.0-, 2.1-, and 2.0-fold compared to the pure FNF in pH 1.2 media, distilled water, and pH 6.8 buffer, which included 0.025 M sodium lauryl sulfate, respectively. The SD2 formulation showed a dissolution percentage of nearly 100 % in all dissolution media after 60 min. The physicochemical properties of the SD2 formulation exhibited slight changes in the melting point and crystallinity of FNF. Moreover, the stability of the SD2 formulation was maintained for six months. In particular, it was challenging to secure stability when starch#1500 was excluded from the SD2 formulation. In conclusion, the dissolution percentage of FNF in the SD2 formulation was improved owing to the weak binding force between FNF and the excipients, stability was secured, and favorable results are expected in future animal experiments.

Enhanced Dissolution and Bioavailability of Curcumin Nanocrystals Prepared by Hot Melt Extrusion Technology.

Curcumin nanocrystals (Cur-NCs) were prepared by hot melt extrusion (HME) technology to improve the dissolution and bioavailability of curcumin (Cur). Cur-NCs with different drug-carrier ratios were prepared by one-step extrusion process with Eudragit® EPO (EEP) as the carrier. The dispersed size and solid state of Cur in extruded samples were characterized by dynamic light scattering (DLS), scanning electron microscope (SEM), differential scanning calorimetry (DSC), and X-ray diffraction (XRD). The thermal stability of Cur was analyzed by thermogravimetric analysis (TGA) and high performance liquid chromatography (HPLC). Dissolution and pharmacokinetics were studied to evaluate the improvement of dissolution and absorption of Cur by nano-preparation. Cur-NCs with particle sizes in the range of 50~150 nm were successfully prepared by using drug-carrier ratios of 1:1, 2:1 and 4:1, and the crystal form of Cur was Form 1 both before and after HME. The extrudate powders showed very efficient dissolution with the cumulative dissolution percentage of 80% in less than 2 min, and the intrinsic dissolution rates of them were 13.68 ± 1.20 mg/min/cm2, 11.78 ± 0.57 mg/min/cm2 and 4.35 ± 0.20 mg/min/cm2, respectively, whereas that of pure Cur was only 0.04 ± 0.00 mg/min/cm2. The TGA data demonstrated that the degradation temperature of Cur was about 250 °C, while the HPLC results showed Cur was degraded when extruded at the temperature over 150 °C. Pharmacokinetic experiment showed a significant improvement in the absorption of Cur. The Cmax of Cur in the Cur-NC group was 1.68 times that of pure Cur group, and the Cmax and area under the curve (AUC0-∞) of metabolites were 2.79 and 4.07 times compared with pure Cur group. Cur-NCs can be prepared by HME technology in one step, which significantly improves the dissolution and bioavailability of Cur. Such a novel method for preparing insoluble drug nanocrystals has broad application prospects.

A Comparative Quality Control Study of Brand and Generic Amlodipine Tablets by In-Vitro Testing

The objective of this study was to conduct in-vitro quality control testing of brand versus generics of Amlodipine tablets. One brand and two generic Amlodipine tablets were used in the study. In the terms of weight variation, Brand, Generic A and Generic B have an above the mean weight limit variation of 2.15%, 2.23%, & 1.43% respectively. The lower mean weight limit variations are 1.85%, 1.92% & 1.23% respectively which are within the 7.5% standard limit of IP. Friability test shows that Brand, Generic A & Generic B have an average friability of 0.5%, 0.480% ,0.3% mass loss, which are within 1%. mass lost limit of IP. Hardness test shows that Brand, Generic A & Generic B have an average hardness of 0.9 kg/cm2, 2.3 kg/cm2 and 1 kg/cm2 respectively. The disintegration test shows that Brand, Generic A & Generic B fall within 15-minutes time interval segment with disintegration time determined 20 sec, 3 min, 2.5 min respectively. In terms of drug assay brand, Generic A & Generic B fall under IP limit of 90% to 110%. The Brand, Generic A & Generic B have a drug dissolution percentage of 101%, 104%, 104% respectively within 30 minutes sampling time interval. The QC tests results for amlodipine tablets show that Brand, Generic A and Generic B confirm to the IP standards.

Antiurolithiatic activity of Indian medicinal plant: Ocimum kilimandscharicum Gurke (Lamiaceae)

Urolithiasis is the most prevalent condition of the urinary system, characterized by the formation of stones inside the urinary tract. It is urgent to look for a natural urolithiasis therapy due to the serious side effects of conventional medications. Hydro-alcoholic (80% v/v) extract of the aerial parts of Ocimum kilimandscharicum (OK) and its ethyl acetate, chloroform, n-butanol, aqueous, and n-hexane fractions were subjected to in vitro antiurolithiatic screening as well as preliminary screening of phytochemicals. The in vitro antiurolithiatic activity of O. kilimandscharicum was studied using its hydroalcoholic extract (HAEOK). Calcium phosphate test using a colorimetric approach and calcium oxalate assay using a titrimetric model were used to determine the proportion of calcium oxalate crystals that dissolved. Total phenolic content (TPC) and total flavonoid content (TFC) were measured for the extract and fractions of OK. Ethyl acetate fraction (EAFOK) had a greater capacity to suppress crystal formation in both the calcium phosphate and calcium oxalate assays. The percent dissolution of calcium oxalate by HAEOK and EAFOK (31.48 ± 0.920% and 39.21 ± 0.903%) and calcium phosphate crystals by HAEOK and EAFOK (59.03 ± 0.820% and 66.62 ± 0.468%) was determined, respectively. At p < 0.05 and p < 0.01, differences between the results were regarded as significant. Cystone was employed as a standard drug. This study revealed that EAFOK showed significant antiurolithiatic activity. The antiurolithiatic activity of the extract/fraction was attributed to the steroids, triterpenoids, and flavonoid content of OK.

Comparison of diterpenoid contents and dissolution profiles of selected Andrographis paniculata crude and extract capsules.

Andrographis paniculata (AP) has been approved by the Thai government for the treatment of mild cases of COVID-19 patients. Increasing use of AP products requires quality control to ensure efficacy and safety. At present, there is no requirement for dissolution test of AP products in the Thai Herbal Pharmacopoeia (THP). This work aimed to examine the contents and dissolution profiles of active diterpenoids, andrographolide (AP1), 14-deoxy-11,12-didehydroandrographolide (AP3), neoandrographolide (AP4), and 14-deoxyandrographolide (AP6) in AP capsules available in Thai markets. Four extract products (EXT. A-D) and three crude powder products (CRD. A-C) were tested for contents by using HPLC-DAD. Dissolution profiles of four diterpenoids were investigated in different media (pH 1.2, 4.5, 6.8, and 0.01 N HCl + SLS) with apparatus II (paddle type). The AP1 contents were 1.99%-2.90% w/w for crude capsules and 2.84%-16.27% w/w for extract capsules. In the dissolution test, the dissolution percentages of four diterpenoids from crude capsules were higher than those from extract capsules except EXT. A. AP1 in most extract products (EXT. B, C, D) was dissolved in all dissolution media at a lower percentage than the other three diterpenoids. EXT. A (aqueous extract) was the only extract capsule showing the amounts of all diterpenoids dissolved in all media >80% in 45 min. The study demonstrated that AP1 content in AP products complied with the acceptance criteria in the THP (80%-120%), and the weight variation also met the United States Pharmacopeia (USP) requirements. However, different dissolution profiles of AP products may lead to different bioavailability of diterpenoids and further affect their efficacy.

Novel fast dissolving freeze dried sublingual baicalin tablets for enhanced hepatoprotective effect: in-vitro characterization, cell viability, and in-vivo evaluation

Baicalin (BG), a natural product, has been used in the prevention and treatment of drug-induced liver injury (DILI); however, its poor solubility and extensive liver metabolism limit its pharmacological use. The aim of the present study was the formulation of fast-dissolving freeze-dried sublingual tablets (FFSTs) to increase BG dissolution, avoid first-pass metabolism, and overcome swallowing difficulties. FFSTs were prepared following a 23 factorial design. The effect of three independent variables namely matrix former, Maltodextrin, concentration (4%, and 6%), binder concentration (2%, and 3%), and binder type (Methocel E5, and Methocel E15) on the FFSTs’ in-vitro disintegration time and percentage dissolution was studied along with other tablet characteristics. Differential scanning calorimetry, scanning electron microscopy, in-vitro HepG2 cell viability assay, and in-vivo characterization were also performed. F8 (6% Maltodextrin, 2% Mannitol, 2% Methocel E5), with desirability of 0.852, has been furtherly enhanced using 1%PEG (F10). F10 has achieved an in-vitro disintegration time of 41 secs, and 60.83% in-vitro dissolution after 2 min. Cell viability assay, in-vivo study in rats, and histopathological studies confirmed that pretreatment with F10 has achieved a significant hepatoprotective effect against acetaminophen-induced hepatotoxicity. The outcome of this study demonstrated that FFSTs may present a patient-friendly dosage form against DILI.

Enhancing the bioavailability of clozapine through microwave-assisted formulation of a stable β-cyclodextrin inclusion complex

The low oral bioavailability of clozapine due to its poor aqueous solubility, poor dissolution rate, and extensive hepatic first-pass metabolism poses a challenge to the effective treatment of psychiatric disorders. The objective of the current research was to address the above issues by developing a clozapine inclusion complex (CLZ-IC) using the microwave irradiation method. To optimize the formulation and processing variables, namely the molar ratio of CLZ to β-CD (X1) and the irritation reaction time (X2), a 32 factorial design was performed. The phase solubility study revealed the formation of a stable inclusion complex with a stoichiometry of 1:1, suggesting that β-cyclodextrin could effectively solubilize clozapine. The characterization data confirmed the formation of the inclusion complex of clozapine in β-cyclodextrin. The optimized inclusion complex showed a solubility of 342 ± 26 µg/ml and a percentage dissolution of 91.1 ± 3.4% after four hours. The inclusion-complex tablets exhibited excellent physical properties and showed an improved in vitro dissolution profile, with 80% of the drug being released within 100 minutes, compared to marketed tablets (80% release in 300 min). In vivo pharmacokinetic studies conducted in a rat model demonstrated an increase in Cmax, area under the curve (AUC), and relative bioavailability by a factor of 2.26 with the optimized formulation, indicating a significant improvement in drug absorption compared to the marketed tablet. The techno-economic analysis suggests a cost-benefit ratio of 25.08 after 7 years, indicating the suitability for large-scale production. Overall, using Design of Experiment, in silico, and in vivo studies proved effective in optimizing the inclusion-complex formation and enhancing the bioavailability of clozapine. In conclusion, the optimized clozapine-β-cyclodextrin inclusion complex prepared using a time-saving (90 sec) and cost-effective microwave irradiation method exhibited excellent physical properties and demonstrated significant improvements in the drug's solubility, dissolution rate, and pharmacokinetic performance.

Enhancing reactivity of granite waste powder toward geopolymer preparation by mechanical activation

Granite waste powder (GWP) is a solid waste produced during stone processing, and its accumulation has brought serious environmental and ecological problems. Due to its rich Si and Al components, GWP is a potential raw material for the preparation of geopolymers, but its low reactivity limits its utilization. This study aimed to enhance the reactivity of GWP toward geopolymer preparation by mechanical activation. During mechanical activation, the particle size of GWP decreased rapidly, and its internal pore volume gradually increased, which made its specific surface area continuously increase. The relative crystallinity of the main mineral phases in GWP decreases continuously with mechanical activation, and the aluminosilicate minerals (including albite, microcline, and biotite) are more easily amorphized than quartz. Leaching tests show that activated GWP can dissolve higher percentages of silicon and aluminum components in alkaline solutions. After 120 min of activation, the dissolution percentage of Si increased from 1.55% to 6.25%, and that of Al increased from 4.83% to 20.86%. The reaction heat result shows that the early geopolymerization involving activated GWP releases higher cumulative heat, which reflects a higher degree of reaction. Also, geopolymer incorporated with activated GWP, its compressive strength increased from 50.83 MPa to 78.94 MPa, and its flexural strength increased from 7.2 MPa to 10.0 MPa. These results confirmed that the reactivity of GWP can be significantly enhanced by mechanical activation. This technology may provide an efficient and promising method to improve the reactivity of GWP and promote its utilization in the preparation of geopolymers.

Quabodepistat (OPC-167832), a Novel Antituberculosis Drug Candidate: Enhancing Oral Bioavailability via Cocrystallization and Mechanistic Analysis of Bioavailability in Two Cocrystals.

Quabodepistat (code name OPC-167832) is a novel antituberculosis drug candidate. This study aimed to discover cocrystals that improve oral bioavailability and to elucidate the mechanistic differences underlying the bioavailability of different cocrystals. Screening yielded two cocrystals containing 2,5-dihydroxybenzoic acid (2,5DHBA) or 2-hydroxybenzoic acid (2HBA). In bioavailability studies in beagle dogs, both cocrystals exhibited better bioavailability than the free form; however, the extent of bioavailability of cocrystals with 2HBA (quabodepistat-2HBA) was 1.4-fold greater than that of cocrystals with 2,5DHBA (quabodepistat-2,5DHBA). Dissolution studies at pH 1.2 yielded similar profiles for both cocrystals, although the percent dissolution differed: quabodepistat-2HBA dissolved more slowly than quabodepistat-2,5DHBA. The poor solubility of quabodepistat-2HBA is likely the primary factor limiting dissolution at pH 1.2. To identify a dissolution method that maintains the bioavailability in beagle dogs, we performed pH-shift dissolution studies that mimic the dynamic pH change from the stomach to the small intestine. Quabodepistat-2HBA demonstrated supersaturation after the pH was increased to 6.8, while quabodepistat-2,5DHBA did not demonstrate supersaturation. This result was consistent with the results of bioavailability studies in beagle dogs. We conclude that a larger quantity of orally administered quabodepistat-2HBA remained in its cocrystal form while being transferred to the small intestine compared with quabodepistat-2,5DHBA.

Spilanthes acmella Extract-Based Natural Oils Loaded Emulgel for Anti-Microbial Action against Dermatitis.

Dermatitis is skin disorder that is complicated by recurrent infections of skin by bacteria, viruses, and fungi. Spilanthol is an active constituent of Spilanthes acmella, which possess strong anti-bacterial properties. The purpose of this study was to develop a herbal emulgel for the treatment of dermal bacterial infections, as microscopic organisms have created solid resistance against anti-microbials. Emulgels were prepared and characterized for parameters such as physical examination, rheological studies, spreading coefficient, bio-adhesive strength measurement, extrudability study, antibacterial activity, FTIR analysis, in vitro drug dissolution, and ex vivo permeation studies. With a statistically significant p-value = 0.024, 100% antibacterial activity was observed by F4 against Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli (mean ± S.D) (25.33 ± 0.28, 27.33 ± 0.5, and 27 ± 0.5). However, maximum antibacterial effect 100% formulations produced zones of inhibitions against E. colip-value = 0.001. The mean zone of inhibition produced by F4 was greatest among all at 26.44 ± 0.37 mm (mean ± S.D). The F4 formulation produced a maximum percentage dissolution, permeation, and flux of 86.35 ± 0.576, 55.29 ± 0.127%, and 0.5532 ug/cm2/min, respectively. The present study therefore, suggests the use of S. acmella extract and olive oil containing emulgel for treating bacterial skin infections.

Optimization of Fast Disintegrating Tablets Diphenhydramine HCl using Co-process of Cross-link Yellow Kepok Banana Starch, Crospovidone, and Microcrystalline Cellulose

Diphenhydramine HCl is an antihistamine drug that is available in conventional tablet form. This study aimed to produce the optimum formula for a diphenhydramine fast disintegrating tablet (FDT) using a modification of starch, crospovidone, and microcrystalline cellulose (MCC) to produce quality tablets that meet the tablet's physical requirements and tablet dissolution. Starch modification was made using a two-step method of starch cross-link, then continued with silica coprecipitation. FDT was prepared by the direct compression method. Optimisation with the simplex lattice design (SLD) model uses three components: co-process starch crosslink-silica, crospovidone, and MCC, which obtained 14 formula designs. The hardness, wetting time, disintegration time, and percent dissolution are optimisation parameters. Equations, contour plots, and desirability values were determined as the optimum formula. Based on the research results, an optimum formula was obtained with the proportion of co-process cross-link starch-silica was 56.185 mg, crospovidone at 6 mg, and MCC at 45.815 mg. The result of hardness was 5 kg, wetting time 51.061 seconds, disintegration time 63.129 seconds, and dissolution was 100.972%. The interaction of the three components reduces hardness and increases disintegration time, wetting time, and percent dissolution.

Insight into the role of dissolution mechanism in the sonochemistry of acoustic cavitation bubble

AbstractUsing a detailed numerical model, in the present work, the dissolution process of the different species generated by the acoustic cavitation bubble was investigated through the analysis of bubble chemistry over a range of wave frequencies from 140 to 515 kHz. It has been observed that during the first bubble collapse, at 140 and 213 kHz, significant amounts of ●OH, O, H●, H2, and O2 molecules (from ~ 2.1×10‐20 to 4.86×10‐18 mol) are dissolved into the bulk liquid (2.84‐0.067%). However, with the rise of ultrasound frequency (>213 kHz), the number and the quantity of the dissolved substances are decreased (<1.16×10‐20 mol) until to be completely suppressed at 515 kHz. Over the first compression period, at 140 and 213 kHz, the dissolution tendency is in the order: H2 (4.86×10‐18‐9.44×10‐19 mol) > H● (4.41×10‐18‐7.76×10‐19 mol) > O (1.8×10‐18‐2.75×10‐19 mol) > ●OH (4.68×10‐19‐1.91×10‐19 mol) > O2 (8.43×10‐20‐2.1×10‐20 mol). Nevertheless, at 355 kHz, the dissolution of the main substances is in the order: H● (1.16×10‐20 mol)>●OH (5.13×10‐21 mol)>H2 (3.59×10‐21 mol). Despite the low dissolution percentages of the different species (compared to the total yield) during the first bubble collapse (<3%), it has been observed that the corresponding molar amounts (depending on the applied frequency) are of great importance (≤ 4.86×10‐18 mol). On the other hand, independently of the number of acoustic cycles (1, 2 or 3), the dissolution tendency of the different species, at 140 and 213 kHz, is in the order: H2 > H● > O > O2 > ●OH > O3 > HO2● > H2O2. Nevertheless, above 213 kHz, this ranking starts to be disturbed with the dominance of the main species, i.e. H2, H●, O, ●OH, and O2 molecules. According to the obtained findings in the present paper, the importance of the dissolution mechanism (into the bubble chemistry) is clearly evidenced; therefore, for an accurate simulation of the chemistry of an acoustic cavitation bubble, the consideration of the dissolution process should be taken into account throughout the bubble's oscillation.

Effectiveness of Dry Grinding and Wet Grinding Methods on Solution and Dissolution Rate of Nimodipine-HPMC Nanoparticles

Nimodipine is a dihydropyridine calcium channel blocker that shares the general properties of nifedipine, but acts mainly on cerebral blood vessels. Nimodipine belongs to the Class II Biopharmaceutical Classification System (BCS) drug group, which has low solubility and high permeability. The purpose of this study was to look at the differences in the yield of nanoparticles between the dry grinding and wet grinding methods on the physicochemical properties, solubility, and dissolution rate of nimodipine nanoparticles. The nanoparticles were prepared a nimodipine: HPMC ratio of 1:0.6 using two different methods. Sample characterization was carried out using Particle Size Analyzer (PSA), Scanning Electron Microscopy (SEM), Differential Scanning Calorimetry (DSC), X-ray Diffraction (XRD), and Fourier Transform Infrared (FT-IR). The Solubility test was carried out in CO2-free distilled water and the dissolution rate was carried out in phosphate buffer pH 7.2. The solubility of pure nimodipine in CO2-free distilled water was 0.339 µg/mL, the physical mixture was 1.948 µg/mL, the dry grinding nanoparticles were 3.367 µg/mL, and the wet grinding nanoparticles were 19.952 µg/mL. The dissolution test results obtained with the percentage of pure nimodipine dissolution at 60th minutes was 33.947%, the physical mixture was 39.482%, the dry grinding nanoparticles were 49.798%, and the wet grinding nanoparticles were 56.484%. Based on the results of the study, it can be said that the nimodipine-HPMC nanoparticles significantly increased the solubility and dissolution rate of nimodipine.

Pork preservation by antimicrobial films based on potato starch (PS) and polyvinyl alcohol (PVA) and incorporated with clove essential oil (CLO) Pickering emulsion

Pickering emulsion (PE) containing clove essential oil (CLO) has been the subject of extensive study because of its superior slow-release, powerful antibacterial and biological capabilities of CLO. In the current work, we have prepared antimicrobial layers with potato starch (PS) and polyvinyl alcohol (PVA) with CLO Pickering emulsion (PEC) and applied them for pork meat preservation. The measured Zeta potential was −21.7 mV. The estimated droplets' diameter was 186 nm, the polydispersity index (PDI) was 0.104, and the encapsulation efficiency (EE) was 57.9%. These results proved that PEC was successfully synthesized, and the high EE value guaranteed the effective antimicrobial effectiveness of CLO. The PEC in PS/PVA matrices was dispersed uniformly. Their homogeneous and smooth structures were proved by Scanning Electron Microscopy, Fourier-Transform Infrared Spectroscopy, and X-ray diffraction. Hydrogen bonds and electrostatic interactions assured the crystallinity of the films and decreased tensile strength (22.4–6.80 MPa) and elongation percentage (375.3%–91.6%). The moisture content, water absorption, water vapour permeability, opacity and colour difference of the antimicrobial films were 8.80%–10.5%, 38.6%–65.9%, 1.70–2.20 × 10−12 g cm/cm2·s·Pa, 3.32–8.95 A/mm and 5.06–7.15, respectively. It is revealed that the antimicrobial layers had excellent dissolution stability and percentage of CLO release rate stability. We applied them for pork preservation, founding they assured a prolonged preservation period (10 days) and showed more potent inhibition of Escherichia coli than Staphylococcus aureus. The antimicrobial films incorporation of PEC exhibited excellent potential in application of pork preservation.

Development and pharmacokinetic evaluation of Neusilin® US2-based S-SNEDDS tablets for bosentan: Fasted and fed states bioavailability, IVIS® real-time biodistribution, and ex-vivo imaging

The study reported here aimed to develop and optimize the S-SNEDDS tablet of bosentan (BOS) and to investigate its pharmacokinetic and biodistribution properties. The BOS-loaded SNEDDS have been developed and characterized in a previous study. The BOS-loaded SNEDDS formulation was converted to S-SNEDDS using Neusilin® US2. The S-SNEDDS tablets were obtained using the direct compression technique, and in vitro dissolution, in vitro lipolysis, and ex-vivo permeability studies of the tablets were performed. The S-SNEDDS tablet and reference tablet (Tracleer®) were administered to male Wistar rats at 50 mg/kg dose by oral gavage in fasted and fed state conditions. The biodistribution of the S-SNEDDS tablet was investigated in Balb/c mice using fluorescent dye. The tablets were dispersed in distilled water before administration to animals. The relationship between in vitro dissolution data and in vivo plasma concentration was examined. The S-SNEDDS tablets showed 2.47, 7.49, 3.70, and 4.39 increases in the percentages of cumulative dissolution in FaSSIF, FeSSIF, FaSSIF-V2, and FeSSIF-V2, respectively, when compared to the reference, and increased the Cmax and AUC 2.65 and 1.28-fold and 4.73 and 2.37-fold in fasted and fed states, respectively, when compared to the reference. S-SNEDDS tablets also significantly reduced interindividual variability in both fasted and fed states (p < 0.05). The XenoLight™ DiR and VivoTag® 680XL labeled S-SNEDDS tablet formulation increased the real-time biodistribution in the body by factors of 2.4 and 3.4 and organ uptake and total emission increased by factors of 2.8 and 3.1, respectively. The IVIVR has been successfully established for S-SNEDDS tablets (R2 > 0.9). The present study confirms the potential of the S-SNEDDS tablet to enhance the in vitro and in vivo performance of BOS.

Analysis of porosity, sealer dissolution and apical extrusion of endodontic sealers: A micro computed tomography study.

The aim of the study was to determine the porosity, dissolution and apical extrusion of AH Plus, MTA Fillapex and EndoSequence BC sealer after immersion in phosphate buffered saline (PBS) using microcomputed tomography (micro-CT). Forty-eight single-rooted teeth were selected. Gutta percha and one of the aforementioned root canal sealers was used for obturation using continuous wave technique. The specimens were scanned after obturation and after seven days of immersion in PBS, by using micro-computed tomography. Porosity, sealer dissolution and apical extrusion were calculated. Statistical analysis was done by using paired t-test, post hoc tukey test and Fischer exact test. Significantly higher percentage of porosity and dissolution of sealer in the apical 4mm was found for MTA Fillapex and EndoSequence BC sealer than for AH Plus. The incidence of apical extrusion was significantly more in MTA Fillapex (56.25%), followed by EndoSequence BC (31.25%) and AH Plus (0%). None of the three root canal sealers exhibited perfect three-dimensional obturation. The sealers manifested porosity, dissolution and apical extrusion to varying degrees both after obturation and after storage in PBS for 7 days.