Dissolution test for oral suspension: an overview about use and importance

Abstract This work aims to ascertain the comprehensiveness of dissolution tests for oral suspensions registered in Brazil and the USA. After consulting literature since 1994, a paucity of information about dissolution methods for suspensions was detected. It makes it difficult to establish the most appropriate test parameters. In January, 2019, there were 46 drugs registered in Anvisa (Brazil) as oral suspension, being 47 reference, 173 generic and 114 interchangeable similar (IS) medicines; while in the USA, 90 drugs were registered as oral suspension by FDA, 235 Abreviatted New Drug Application and 111 New Drug Application medicines. Out of 46 and 90, only six and 15 drugs as oral suspension had a pharmacopeial dissolution test, corresponding to 70 (20.9%) and 82 (23.7%) products in Brazil and the USA, respectively. Dissolution studies were found for 17 drugs as oral suspension in the non-compendial literature. Dissolution test conditions were established to few marketable oral suspension drugs, most of which are BCS class II or IV. Thus, investing in dissolution studies could subsidize the registration of these products by regulators, especially for generic and IS drugs, by comparing dissolution profiles, and predicting their in vivo behavior to avoid exposure of healthy individuals to clinical research.

Optimization of formulation of paclitaxel nanosuspension encapsulated by erythrocyte membrane based on Box-Behnken method / 中国中药杂志

In view of the longevity and innate immune escape of red blood cells, this study designed the red blood cell membrane-coated paclitaxel nanosuspension [RBC-(PTX)NS] and investigated its physicochemical properties and antitumor effect in vitro. Paclitaxel nanosuspension [(PTX)NS] was prepared by ultrasonic precipitation and then RBC-(PTX)NS by ultrasonic coating. The formulation of(PTX)NS was optimized with Box-Behnken method and indexes of particle diameter, zeta potential, and stability. The morphology, particle diameter, stability, in vitro dissolution, and antitumor effect of(PTX)NS and RBC-(PTX)NS were characterized. The results showed that the particle diameter and zeta potential were(129.38±0.92) nm and(-22.41±0.48) mV, respectively, for the optimized(PTX)NS, while(142.5±0.68) nm and(-29.85±0.53) mV, respectively, for RBC-(PTX)NS. Under the transmission electron microscope,(PTX)NS was spherical and RBC-(PTX)NS had obvious core-shell structure. RBC-(PTX)NS remained stable for 5 days at 4 ℃. The in vitro dissolution test demonstrated that the cumulative release rate of RBC-(PTX)NS reached 79% within 20 min, which was significantly higher than that(25%) of(PTX)NS(P<0.05). As evidenced by MTT assay, RBC-(PTX)NS highly inhibited the proliferation of HepG2 cells in a dose-dependent manner. The cell membrane-coated nano-preparation preparation method is simple and reproducible. It improves the solubility of PTX and endows RBC-(PTX)NS with higher stability and stronger cytotoxicity. Thus, it is a new method for the delivery of PTX via nanocrystallization.

Equilibrium solubility study to determine fexofenadine hydrochloride BCS class and challenges in establishing conditions for dissolution profiles applied to suspension

The aim of this work was to perform solubility studies for fexofenadine hydrochloride and establish dissolution conditions for this drug in oral suspension dosage form. The solubility study was executed through the shake-flask method, below 37 ºC±1 ºC, at 100 rpm stirring for 12 h in three buffer solutions: hydrochloric acid pH 2.0, acetate pH 4.5 and phosphate pH 6.8. The dissolution test was developed in vessels containing 900 mL of the same buffer, employing the paddle apparatus in speed of 25 and 50 rpm, below 37 ºC±0.5 ºC. The drug was classified as low solubility according to the Biopharmaceutics Classification System, since the dose/solubility ratio was higher than 250 mL in all media tested (326.55 mL in buffer pH 2.0; 2,456.33 mL in buffer pH 4.5 and 1,021.16 mL in buffer pH 6.8). The dissolution test showed that a release of 85% in 30 min could be established. The rotation speed of 25 rpm, media volume of 900 mL and insertion of the samples through weighted syringes are adequate. The buffered media pH 2.0 could be chosen as dissolution media.

Preparation and quality evaluation of orodispersible film containing ginkgolide B novel nanosuspension lyophilized powder / 中国中药杂志

To prepare a new dosage form that can improve the drug loading of the film--ginkgolide B nanosuspension lyophilized powder orodispersible film(GB-NS-LP-ODF) and to evaluate its quality. Firstly, ginkgolide B nanosuspension(GB-NS) was prepared by media milling method, and then ginkgolide B nanosuspension lyophilized powder(GB-NS-LP) was prepared with freeze-drying method. The mannitol was used as lyoprotectant and its dosage was also investigated. GB-NS-LP-ODF was prepared by solvent casting method and its formulation was screened by single factor test method and optimized by orthogonal test. The appearance, mechanical properties, content uniformity and in vitro dissolution of the optimized GB-NS-LP-ODF were investigated. The particle size of prepared GB-NS was about 201 nm, and the optimal dosage of mannitol was 8%. According to the optimal formula, the GB-NS-LP-ODF was prepared with GB-NS-LP 35.6%, PVA 0588 49.4%, PEG 400 10.7% and CMS-Na 4.3%, and completely disintegrated in about 30 s, and the particle size of reconstituted GB nanoparticles from ODF was about 210 nm. The film with smooth appearance and good mechanical properties was stable within 30 days and the content uniformity(A+2.2 S<15) conformed to the regulations. Scanning electron microscope(SEM) showed that GB-NS-LP-ODFs were evenly distributed and the particle size was about 200 nm. X-rays diffraction(XRD) showed that its crystallinity was significantly lower than that of GB raw drug and GB-ODF. The results of in vitro release test showed that the drug film was completely dissoluted within 10 minutes. These results indicated that nanosuspension lyophilized powder was prepared by freeze drying of nanosuspensions, and then loaded into the orodispersible film to effectively increase the drug loading of the ODF and have broad application prospects.

Preparation, characterization and dissolution characteristics of dragon's blood extract nanosuspensions / 中国中药杂志

The single-factor test was used to optimize the high-pressure homogenization method to prepare the phenolic extract nanosuspensions(DBNs). The physicochemical properties of the obtained nanosuspensions were characterized and the cumulative release in vitro was evaluated. The results showed that the drug concentration was 0.5 g·L~(-1), the mass concentrations of PVPK30 and SDS were 0.5 and 0.25 g·L~(-1), respectively, the probe ultrasonic time was 5 min, the homogenization pressure was 900 bar, and the number of homogenization was 2 times. The prepared DBNs had an average particle size of(168.80±0.36) nm, polydispersity index(PDI) of 0.09±0.04, stability index(SI) of 0.85, and DBNs were stable for storage within 30 days. Scanning electron microscopy showed that the particle size of the dragon's blood extract was reduced and the uniformity was improved in the obtained nanosuspensions. X-ray diffraction pattern and differential scanning calorimetry showed that the phenolic extract of dragon's blood was still in an amorphous state after being prepared into nanosuspensions. The results of saturated solubility measurement showed that the solubility of DBNs lyophilized powder reached 6.25 g·L~(-1), while the solubility of DB raw powder was only 28.67 mg·L~(-1). The in vitro dissolution experiments showed that DBNs lyophilized powder accumulated in gastrointestinal fluid for 8 h. The release amount was 90%,the cumulative release of the raw powder in the gastrointestinal fluid for 24 h was less than 1%, and the solubility and dissolution rate of the DBNs lyophilized powder were significantly higher than the DB raw powder. The method is simple in process and convenient in operation, and can successfully prepare uniform and stable nanosuspensions to improve its solubility, and provides a research basis for solving the application limitation of dragon's blood extract.

Optimization of noni callus induction and establishment of callus suspension system / 生物工程学报

The aim of the study was to obtain the secondary metabolites in the stem segment of noni and to establish genetic transformation system. The stem segments (no axillary buds) of noni were used as explants to induce the callus, and then to establish the cell suspension system. The factors affecting callus induction and cell suspension were studied. The results showed that the optimal culture medium for induction was MS with 1.0 mg/L 6-Benzylaminopurine (6-BA) and 0.1 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D), and the optimum culture medium for suspension was MS with 1.0 mg/L 6-BA and 0.1 mg/L 2,4-D, 3% sucrose and the pH of 5.85, with the initial inoculation amount of 37.5 g/L, and the speed of 110 r/min and 25±2 °C applying darkness culture. The suspension cells grew well and showed the maximum growth rate. The growth curve of the suspension cells from the stem segment of noni was in "S-typed" trend, and it should be transformed to the fresh medium between 12 and 20 d. During the culture, the pH of the culture medium decreased and then slowly increased, and the optimum pH for the suspension cells culture of callus from noni's stem segments was 4.5-5.0. In this study, the stable cell suspension system of the stem segment of noni was successfully established.

Annual Report of Korean Association of External Quality Assessment Service on Histocompatibility Testing (2018) / 임상검사와정도관리

Here, we report the results of the first histocompatibility proficiency testing (PT) performed by the Korean Association of External Quality Assessment Service in 2018. The directly prepared PT specimens of whole blood, sera, and mononuclear cell suspensions were distributed to participants biannually. The number of participants was comparable to that in the previous external PT program, and the response rate was 88%–100%. The accuracy rates for human leukocyte antigen (HLA) A, B, C, DR, and DQ low and high resolution typing were 100%/100%, 100%/98%, 100%/99%, and 99%/98%, respectively; HLA-B27 typing, 99.1%; T cell and B cell crossmatching, 3.1% and 6.0%, respectively; and HLA antibody screening and identification, 100% and 100%, respectively. The results of HLA crossmatching were not reported from four participants due to poor cell viability. Further improvements of the specimen delivery process, grading criteria for crossmatching, and format of participant summary are warranted.

Thermoresponsive and Biodegradable Amphiphilic Block Copolymers with Pendant Functional Groups

BACKGROUND: To develop the biodegradability and thermoresponsive hydrogel, in this work we designed a pendant-functionalized, thermoresponsive, amphiphilic block copolymer. METHODS: Methoxy poly(ethylene glycol) (MPEG)-b-[poly(ε-caprolactone)-ran-poly(ε-caprolactone-3-one)-ran-polylactic acid] (MCL) and (MPEG-b-[PCL-ran-POD-ran-PLA]) [MCL-(CO)] block copolymers were prepared by ringopening polymerization of ε-caprolactone, OD and lactide monomers. The subsequent derivatization of MCL-(CO) provided MPEG-b-[PCL-ran-poly(ε-caprolactone-3-COOH)-ran-PLA] [MCL-(COOH)] with COOH pendant groups and MPEG-b-[PCL-ran-poly(ε-caprolactone-3-NH2)-ran-PLA] [MCL-(NH2)] with NH2 pendant groups. RESULTS: The measured segment ratios of MCL-(CO), MCL-(COOH), and MCL-(NH2) agreed well with the target ratios. The abundances of the COOH and NH2 groups in the MCL-(COOH) and MCL-(NH2) copolymers were determined by 1H- and 13C-nuclear magnetic resonance spectroscopy, and agreed well with the target abundances. MCL-(CO), MCL-(COOH), and MCL-(NH2) formed homogeneous, white, opaque emulsions at room temperature. Rheological analysis of the block copolymer suspensions indicated a solution-to-hydrogel phase transition as a function of temperature. The solution-to-hydrogel phase transitions and the biodegradation of MCL-(CO), MCL-(COOH), and MCL-(NH2) were affected by varying the type (ketone, COOH, or NH2) and abundance of the pendant groups. CONCLUSION: MCL-(CO), MCL-(COOH), and MCL-(NH2) with ketone, COOH, and NH2 pendant groups showed solution-to-hydrogel phase transitions and biodegradation behaviors that depended on both the type and number of pendant groups.

Ethanol changes atpB gene expression and proton permeability in Streptococcus mutans / 대한구강보건학회지

OBJECTIVES: As a first step to study the anticaries effect of ethanol alone, we investigated the effects of ethanol on the expression levels of the atpB gene and proton permeability of Streptococcus mutans in suspension cultures. METHODS: S. mutans UA159 was grown in brain heart infusion medium at either pH 4.8 or 6.8. The total extracted RNA was reverse-transcribed into cDNA using a Superscript™ First-Strand Synthesis System. The resulting cDNA and negative controls were amplified by ABI PRISM 7700 real-time PCR system with SYBR Green PCR Master Mix. For proton flux assay, bacterial suspensions were titrated to pH 4.6 with 0.5 M HCl, and then additional 0.5 M HCl was added to decrease the pH values by approximately 0.4 units. The subsequent increase in pH was monitored using a glass electrode. Ten percent (v/v) butanol was added to the suspensions at 80 min to disrupt the cell membrane. RESULTS: In a concentration-dependent manner, ethanol alone not only decreased the growth rate of S. mutans and the expression of the atpB gene but also increased the proton permeability at both pH 4.8 and 6.8. CONCLUSIONS: These findings suggest that ethanol has the potential for an anticaries ingredient. We believe that ethanol may be used together with fluoride and/or other cariostatic agents in order to develop better anticaries toothpastes and/or mouthrinses.

Desenvolvimento de método para avaliação do perfil de dissolução de suspensões de mebendazol / Method development for dissolution profile evaluation of mebendazol suspensions

Este trabalho teve por finalidade desenvolver um método para a caracterização do perfil de dissolução de suspensões de mebendazol (MBZ), discriminatório para as formas polimórficas do fármaco. Pertencendo a classe II do Sistema de Classificação Biofarmacêutica (SCB), além da baixa solubilidade, o MBZ é bastante crítico por apresentar-se comercialmente disponível em duas formas polimórficas (A e C) e misturas destas. Além disso, pouca informação é encontrada acerca de métodos de dissolução de suspensões. O material apresentado está dividido em três capítulos, sendo o primeiro deles uma revisão da literatura sobre a dissolução de suspensões de fármacos que apresentam polimorfismo. Neste capítulo é feita uma abordagem sobre questões relacionadas ao desenvolvimento de métodos, como inserção das amostras na cuba de dissolução, agitação, uso de tensoativos no meio e a quantificação do fármaco. No segundo capítulo é apresentado o desenvolvimento do método de dissolução, com ênfase no estudo da solubilidade das formas polimórficas A e C de MBZ e sua interação com tensoativos. Foram realizados ensaios de solubilidade pelo método do equilíbrio, cálculo de concentração micelar crítica para os tensoativos lauril sulfato de sódio e polissorbato 80, sendo ao final realizado delineamento experimental (DOE) para o desenvolvimento do método. Pela avaliação do DOE, o local de inserção da amostra não influencia a dissolução de MBZ, por outro lado, a presença de tensoativo, assim como a forma polimórfica empregada, exercem efeito nos resultados apresentados. A partir destas informações, o método indicado para avaliação das suspensões de MBZ com potencial discriminatório de suas formas polimórficas foi definido pela utilização do aparato 2 (pá) a 75 rpm, com 2 litros de HCl 0,1 M sem tensoativo, como meio de dissolução. No último capítulo, o método desenvolvido foi utilizado na avaliação de especialidades farmacêuticas adquiridas no Brasil e em alguns países da América Latina, sendo os respectivos perfis de dissolução, comparados por meio de uma análise multivariada de componentes principais, com formulações contendo o MBZ em diferentes proporções de polimorfos. A partir dos resultados, foi possível observar que grande parte das formulações comercializadas não apresentaram perfil de dissolução satisfatório, isso pode estar relacionado com a presença considerável de polimorfo A nas matérias-primas utilizadas, comprometendo assim a sua solubilidade

The aim of this work was to develop a method for characterization of the dissolution profile of mebendazole (MBZ) suspensions, being discriminatory for the polymorphic forms of the drug. MBZ belongs to class II of the Biopharmaceutics Classification System (BCS), besides its low solubility, it is very critic, being commercially available in two polymorphic forms (A and C) and their mixtures. Moreover, there is low information about dissolution methods for suspensions. The text presented herein is divided into three chapters, the first chapter is a literature review about dissolution of suspensions containing drugs that present polymorphism. In this chapter is made a discussion about the variables of the method, as sample insertion in the dissolution vessel, rotation speed, use of surfactants in the dissolution medium and drug quantification. The development of the dissolution method, focused on the solubility study of MBZ polymorphic forms A and C and their interaction with surfactants is presented in the chapter 2. Some tests were performed: solubility using shake flask method, calculation of micellar critical concentration for the surfactants sodium lauryl sulphate and polysorbate 80, and an experimental design (DOE) was done for developing the method. By DOE evaluation, the sample insertion site does not influence on MBZ dissolution, but the presence of surfactant and the polymorphic form used, show effect on the results. Based on these information, the method indicated for evaluation of MBZ suspensions, with discriminatory power for its polymorphic forms was defined by using apparatus 2 (paddle) at 75 rpm and 2 L of 0.1M HCl without surfactant as dissolution medium. In chapter 3, the method developed was used to evaluate pharmaceutical suspensions from Brazil and from some countries of Latin America. The respective dissolution profiles were compared by means of multivariate analysis of principal components with formulations containing MBZ in different polymorphs ratios. From the results, it was possible to observe that a great part of the commercially available formulations do not presented a satisfactory dissolution profile, and this fact can be related to a considerable amount of the crystalline form A in the raw material, which compromises its solubility

Research progress on and behaviors of poorly soluble Chinese materia medica nanosuspension / 中国中药杂志

Nanosuspension (also called nanocrystal suspension or nanocrystal) could significantly enhance the saturated solubility and dissolution of insoluble drugs, and improve their bioavailability by reducing particle size and increasing the specific surface, which could then solve the delivery problems of the poorly soluble active ingredients and effective parts of Chinese materia medica (CMM). Based on the brief summaries of nanosuspension preparation methods, this paper would mainly review the and behaviors of poorly soluble CMM nanosuspension, discuss and analyze its problems, so as to provide reference and thinking for the further study of nanosuspension drug delivery system of poorly soluble CMM and promote the development and perfection of nanosuspension technology in CMM.

Cell suspension examination versus histopathological technique in detecting sperm in the testis tissue of non-obstructive azoospermia patients undergoing testicular sperm aspiration / 中华男科学杂志

<p><b>Objective</b>To explore the clinical selection and application of cell suspension examination (CSE) or histopathological technique (HPT) in detecting sperm in the testis tissue obtained by testicular sperm aspiration (TESA) in patients with non-obstructive azoospermia (NOA).</p><p><b>METHODS</b>Totally, 1 006 NOA patients underwent TESA and their testis tissues were subjected to CSE or HPT for sperm detection. Based on the results of CSE, the testicular tissue samples were divided into groups A (with sperm, n = 567) and B (without sperm, n = 439) and the results were compared with those of HPT.</p><p><b>RESULTS</b>HPT showed 508 cases with but 59 without sperm in group A, and 403 with and 36 without sperm in group B. The consistency rate of CSE with that of HPT was 90.56% (Kappa =0.809), and CSE exhibited a significantly higher rate of sperm detection than HPT (56.36% vs 54.08%, P=0.023).</p><p><b>CONCLUSIONS</b>CSE combined with HPT for detecting sperm in the testis tissue of NOA patients undergoing diagnostic TESA helps clinical diagnosis and treatment. The results of CSE have a decisive significance for assisted reproductive therapy, while those of HPT may provide some definite etiological evidence for drug therapy or surgery.</p>

Ethanolic extract of Garcinia mangostana L. pericarp as preservative in antacid suspension

Objective@#The study was conducted to determine the preservative activity of ethanolic extract of mangosteen (Garcinia mangostana L.) pericarp and its compatibility in an antacid suspension.@*Methods@#The extract was subjected to phytochemical screening and was used as preservative in a formulated antacid suspension. Compatibility with the active pharmaceutical ingredient (API) and excipients were analyzed using fourier transform-infrared spectroscopy. Preservative activity of the formulation against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa was assessed using the United States Pharmacopoeia (USP) antimicrobial effectiveness test, with methylparaben as positive control and suspension without preservative as negative control.@*Results@#The extract exhibited pharmaceutical compatibility with API and excipients. The formulation revealed comparable reduction in microbial count of E. coli, S. aureus, and P. aeruginosa with positive control at Day 14 (p=0.916, 0.624, 0.335). At Day 28, comparable activity with positive control was only observed against E. coli and S. aureus (p=0.999, 0.854). However, it displayed significant increase in activity against P. aeruginosa (p=0.010) at Day 28. These activities may be attributed to glycosides and reducing substances present in the extract.@*Conclusion@#The ethanolic extract from Garcinia mangostana L. pericarp acted as a preservative in the formulation of an antacid suspension. It conformed to the USP criteria for antimicrobial effectiveness test on bacteria.

Neutrophil oxidative burst as a diagnostic indicator of IgG-mediated anaphylaxis

BACKGROUND: IgG-mediated anaphylaxis occurs after infusion of certain monoclonal antibody-based therapeutics. New in vitro tests are urgently needed to diagnose such reactions. We investigated whether allergens trigger neutrophil oxidative burst (OB) and if neutrophil OB occurs due to allergen-specific IgG (sIgG). METHODS: Neutrophil OB was measured by dihydrorhodamine 123 flow cytometry using a leukocyte suspension spiked with a very small patch of the allergen crude extract, Dermatophagoides farinae (Der f). The mean fluorescence intensity ratio of stimulated to unstimulated samples was calculated as the neutrophil oxidative index (NOI). RESULTS: The Der f-specific NOI (Der f-sNOI) showed a time-dependent increase after Der f extract addition. At 15 min activation, higher Der f-sIgG levels were associated with lower Der f-sNOI values in 31 subjects (P < 0.05). This inverse relationship occurs due to the initial blocking effect of free Der f-sIgG. Additionally, neutrophil OB was nearly absent (Der f-sNOI of −1) in two cases: a subject with undetectable Der f-sIgG levels and washed leukocyte suspensions deprived of Der f-sIgG. CONCLUSION: Allergens can trigger neutrophil OB via preexisting allergen-sIgG. Neutrophil OB can be easily measured in a leukocyte suspension spiked with the allergen. This assay can be used to diagnose IgG-mediated anaphylaxis.

Factors Affecting Hemagglutinations Strength in ABO Blood Group Typing Test Using the Tube Method

BACKGROUND: The ABO blood group typing test (ABO test) is an initial pre-transfusion test based on hemagglutination. Although various factors affect hemagglutination strength, few studies have examined how these factors can be applied in clinical laboratories and their effects on hemagglutination. This study was conducted to analyze the factors affecting hemagglutination strength in the ABO test using a tube method applied in many laboratories. METHODS: We conducted a detailed questionnaire survey of 51 laboratories which use the ABO test with a tube method. We also analyzed the results of the ABO test (cell and serum typing) with 40 specimens using factors affecting hemagglutination at a tube method and applied differently in each laboratory. RESULTS: Each laboratory used various methods to prepare red cell suspensions as specimens or reagents and used different reagent to sample ratios, centrifugation protocols, and shaking test tubes before evaluating hemagglutination strength. By testing various combinations of these factors, direct sampling from the red cell layer of the original specimen was found to have the largest effect on lowering hemagglutination strength in cell typing tests. In serum typing tests, various factors influenced hemagglutination strength, including shaking the tube before analysis and the concentration of a home-made red cell suspension used as a reagent. CONCLUSIONS: To achieve accurate results in the ABO test by the tube method, detailed guidelines that include the factors affecting hemagglutination strength determined in this study should be established.

Evaluation of the efficacy of pediatric suspension of praziquantel against schistosoma mansoni in experimental animals

Background: Schistosomiasis is one of the neglected tropical diseases with recent evidences about the high prevalence among preschool-age children. The pediatric formulation of Praziquantel [PZQ] has to be assessed for the efficacy as it gave controversial results in several countries

Objective[s]: The current study aimed at evaluating the efficacy of the pediatric suspension of PZQ against Schistosoma mansoni Egyptian strain in the experimental animals

Methods: 150 Swiss albino mice infected with Schistosoma mansoni were divided into three groups, the first group was treated with 600 mg/kg body weight of PZQ pediatric suspension, the second group was treated with 600 mg/kg PZQ tablets and the third one received no treatment as a control. The efficacy of the pediatric formulation was experimentally evaluated in comparison with the tablet formulation as a benchmark on the basis of the following specific parasitological parameters [worm burden, tissue egg load, and oogram pattern i.e. percentage of dead, live or immature eggs shown in the stool sample]

Results: The comparison between the mean egg count per gram stool in the two groups pediatric suspension of PZQ [Epiquantel] and adult tablets of PZQ [Distocide], and the control group by applying one way ANOVA revealed a statistically significant difference [p<0.05] between the mean egg count in both treated groups [Epiquantel and Distocide] and their control group. The reduction of the total worm burden caused by Epiquantel[registered] was 96.9%, while that of Distocide[registered] was 86.7%, they were found to be statistically significant[p<0.05] in comparison with the control group. Epiquantel[registered] reduced the male worms by 100% and the females were reduced by 94.1%. Distocide showed a similar effect, it reduced the worms by 88.4% and 85.1% for males and females respectively. The administration of a single oral dose of both Epiquantel[registered] and Distocide[registered] resulted in a statistically significant reduction [p<0.05] in the mean egg count per gram tissue either the liver or the wall of small intestine when compared to their infected untreated control group. Complete absence of immature egg stages, high reduction in the mature eggs, and the increase in the dead eggs were observed in both Epiquantel[registered] and Distocide[registered] groups when compared to the control group

Conclusion: The results prescribed that the pediatric suspension formula of PZQ is as efficient as the tablet formula against Schistosoma mansoni [Egyptian CD strain] in the mouse model. It could be recommended for pediatric treatment

Improved in vitro and in vivo performance of carbamazepine enabled by using a succinic acid cocrystal in a stable suspension formulation

Currently cocrystals are considered as an established approach for making crystalline solids with overall improved physico-chemical properties. However, some otherwise well behaving cocrystals undergo rapid dissociation during dissolution, with ultimate conversion to parent drug and thus apparent loss of improved solubility. The polymeric carriers are long known to manipulate this conversion during dissolution to parent crystalline drug, which may hinder or accelerate the dissolution process if used in a dosage form. The goal of this study was to deliver in vivo a more soluble carbamazepine-succinic acid [CBZ-SUC] cocrystal in suspension formulation utilizing Hydroxypropyl methyl cellulose [HPMC-AS] as a crystallization inhibitor and Polyvinyl carpolactam-polyvinyl acetate-polyethylene glycol graft co-polymer® as solubilizer. The concentration of these polymers were systemically varied during in vitro dissolution studies, while selected formulations from dissolution studies were tested in vivo. Pharmacokinetic studies [PK] in rabbits demonstrated that formulation F-X [1% cocrystal, 1% HPMC-AS and 2% Polyvinyl carpolactam-polyvinyl acetate-polyethylene glycol graft co-polymer caused almost 6fold improvement in AUCo-72 as well as much higher C[MAX] of 4.73microg.mL[+1] to that of l.OTmicrog.mL[+1] of unformulated 'neat' cocrystal given orally. When reference formulation of CBZ [F5-X] with similar composition to F-X were given to rabbits, cocrystal formulation gave 1.37fold bioavailability than CBZ reference formulation. C[MAX] of reference formulation observed was 3.9microg.mL

Evaluation of C. Albicans and S. Mutans adherence on different provisional crown materials

PURPOSE: Bacterial adhesion on provisional crown materials retained for a long time can influence the duration for which permanent prosthetic restorations can be healthily worn in the oral cavity. The aim of this study was to compare seven different commonly used provisional crown materials with regard to Streptococcus mutans and Candida albicans surface adhesion. MATERIALS AND METHODS: For each group, twenty specimens of the provisional fixed prosthodontic materials TemDent (Schütz), Imıdent (Imıcryl), Tab 2000 (Kerr), Structur Premium (Voco), Systemp (Ivoclar Vivadent), Acrytemp (Zhermack), and Takilon-BBF (Takilon) were prepared (diameter, 10.0 mm; height, 2.0 mm). Surface roughness was assessed by atomic force microscopy. Each group was then divided into 2 subgroups (n=10) according to the microbial suspensions used: S. mutans and C. albicans. The specimens were incubated at 37℃ with S. mutans or C. albicans for seven days. Bacterial adherence on surfaces was assessed using the 2,3-bis[2-methyloxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide (XTT) assay. RESULTS: S. mutans showed maximum adhesion to Structur, followed by Systemp, Acrytemp, Takilon, Tab 2000, Imident, and TemDent (P<.05). The highest vital C. albicans adhesion was noted on Takilon, followed by Imident and Tab 2000; the lowest adhesion was noted on Systemp (P<.05). CONCLUSION: The materials showed significant differences in the degree of bacterial adhesion. C. albicans showed higher surface adhesion than S. mutans on provisional crown and fixed partial denture denture materials.

Kinematic and spermatic recovery after selection by centrifugation in colloid solutions of ovine cryopreserved semen / Cinética e recuperação espermática após seleção por centrifugação em soluções coloidais de sêmen ovino criopreservado

Frozen and thawed ovine semen undergo morphological and functional changes that prevent or decrease the efficiency of fertilization. Sperm selection methods seek to improve the quality and viability of the fertilizing materials. Four sperm selection methods were employed, using two silica colloidal solutions coated with silane (silica colloidal-silane) or by polyvinylpyrrolidone (silica colloidal-PVP), and varying the volume of colloidal solution. Sperm kinematic and sperm recovery were evaluated by means of CASA. The protocols using silica colloidal-silane showed higher total motility (TM), progressive motility (PM) and percentage of rapid sperm (%RAP) compared to the methods employing silica colloidal-PVP and to the samples prior to sperm selection. The silica colloidal-PVP had greater sperm recovery compared to the silica colloidal-silane. Only the method using 4mL of silica colloidal-PVP was not efficient in selecting samples with better quality compared to the samples analyzed prior to sperm selection. The methods using lower volumes of colloidal solution did not differ from those using higher volumes and the best results were shown by the method with 1mL silica colloidal-silane. The results found in the study indicated greater efficiency of the silica colloidal-silane solution for sperm selection of thawed ovine semen when compared to selection using silica colloidal-PVP. The method using 1mL of silica colloidal-silane was equally efficient to the method with higher volume, presenting itself as an alternative to process samples with lower sperm concentration.(AU)

O sêmen ovino congelado e descongelado sofre alterações morfofuncionais que impossibilitam ou diminuem a eficiência na fecundação. Os métodos de seleção espermática visam melhorar a qualidade e a viabilidade do material fecundante. Foram utilizados quatro métodos de seleção espermática utilizando duas soluções de sílica coloidal revestida por silano (sílica coloidal-silano) ou por polivinilpirrolidona (sílica coloidal-PVP), variando o volume de solução coloidal. Foram testadas a cinética espermática no CASA e a recuperação espermática. Os protocolos utilizando sílica coloidal-silano apresentaram maior motilidade total (MT), motilidade progressiva (MP) e porcentagem de espermatozoides rápidos (% RAP) quando comparados aos métodos utilizando a sílica coloidal-PVP e às amostras antes da seleção espermática. A sílica coloidal-PVP teve maior recuperação espermática quando comparada à sílica coloidal-silano. Somente o método utilizando 4mL de sílica coloidal-PVP não foi eficiente na seleção de amostras com melhor qualidade quando comparado às amostras analisadas antes da seleção espermática. Os métodos utilizando menores volumes de solução coloidal não diferiram dos métodos de maior volume, sendo a sílica coloidal-silano com 1mL o método que apresentou os melhores resultados. Como conclusão, os resultados encontrados no trabalho apontaram a maior eficiência da sílica coloidal-silano em selecionar sêmen ovino congelado e descongelado quando comparado à seleção em sílica coloidal-PVP. O método utilizando 1mL de sílica coloidal-silano foi igualmente eficiente ao método com maior volume, sendo uma alternativa para processar amostras com baixa concentração espermática.(AU)