Myostatin-mediated regulation of skeletal muscle damage post-acute Aeromonas hydrophila infection in Nile tilapia (Oreochromis niloticus L.).

This study focuses on the relationship between myostatin (MyoS), myogenin (MyoG), and the growth hormone/insulin-like growth factor-1 (GH/IGF-1) axis for muscle growth and histopathological changes in muscle after an Aeromonas hydrophila infection. A total number of 90 Nile tilapia (55.85 g) were randomly allocated into two equal groups of three replicates each. The first group was an uninfected control group that was injected intraperitoneally (ip) with 0.2 ml phosphate buffer saline (PBS), while the second group was injected ip with 0.2 ml (1.3 × 108 CFU/ml) Aeromonas hydrophila culture suspension. Sections of white muscle and liver tissues were taken from each group 24 h, 48 h, 72 h, and 1 week after infection for molecular analysis and histopathological examination. The results revealed that with time progression, the severity of muscle lesions increased from edema between bundles and mononuclear inflammatory cell infiltration 24 h post-challenge to severe atrophy of muscle bundles with irregular and curved fibers with hyalinosis of the fibers 1 week postinfection. The molecular analysis showed that bacterial infection was able to induce the muscle expression levels of GH with reduced ILGF-1, MyoS, and MyoG at 24 h postinfection. However, time progression postinfection reversed these findings through elevated muscle expression levels of MyoS with regressed expression levels of muscle GH, ILGF-1, and MyoG. There have been no previous reports on the molecular expression analysis of the aforementioned genes and muscle histopathological changes in Nile tilapia following acute Aeromonas hydrophila infection. Our findings, collectively, revealed that the up-and down-regulation of the myostatin signaling is likely to be involved in the postinfection-induced muscle wasting through the negative regulation of genes involved in muscle growth, such as GH, ILGF-1, and myogenin, in response to acute Aeromonas hydrophila infection in Nile tilapia, Oreochromis niloticus.

Can a monthly exenatide extended release regimen provide a therapeutic and cost benefit?

Exenatide is used to treat type 2 diabetes mellitus. The current regimen is a 2 mg extended release (ER) weekly injection. The aim of our study was to prove the efficacy of exenatide ER if administered once-monthly. The proposed monthly dose was based on an Excel simulation using pharmacokinetic parameters extracted using Plot Digitizer® (version 2.6.8) from Cirincione et al. (2017), as well as accounting for the exenatide ER formulation characteristics, in vivo and in vitro exenatide stability. A PBPK model of exenatide molecule was developed using (Simcyp® version 19) based on data from in vitro and clinical PK studies. The model was used to confirm the Excel simulation findings of the effectiveness of exenatide ER monthly in maintaining the plasma level above the minimum effective concentration (MEC). Our simulation from Excel and Simcyp® showed that the drug plasma levels of the once monthly ER dose maintained a steady state concentration (Css ) above the MEC. The simulated Excel plasma level ranged from Cmin to Cmax of 60-130ng/L, respectively. The exenatide compound was successfully modeled and used to predict the Css of the ER monthly dose. The Simcyp® simulated Css of the ER was 117 ng/L. A monthly exenatide ER dose provides a plasma level within the therapeutic range. This new proposed dose has a significant pharmacoeconomic benefit and could well improve patient adherence.

Seizure outcome and epilepsy patterns in patients with cerebral palsy.

PURPOSE: The aim of the present study was to investigate epilepsy patterns and outcomes in patients with cerebral palsy (CP) and identify the variables that determine remission. METHODS: This was a retrospective cohort study. We followed 107 CP patients aged 1-16 years with newly diagnosed epilepsy. The patients were categorized according to their remission outcome, uninterrupted freedom of seizure for 2 years or longer, and 4 epilepsy patterns: A) sustained freedom from seizures before 6 months of treatment; B) delayed but sustained seizure freedom; C) relapsing-remitting course; and D) seizure freedom never attained. The variables were analysed for their prognostic relevance to the outcomes RESULTS: A total of 107 patients were included; their mean age at epilepsy diagnosis was 4.2 years (SD 2.5). By the end of the 8-year follow up, 19.6% 26.1%, 31.7%, and 22.4% were in sustained remission, terminal remission, relapse, and no remission respectively. Pattern A was identified in 6.5% of the patients, pattern B in 27.1%, pattern C in 43.9%, and pattern Din 22.4%. Univariate analysis revealed that the type of CP, mobility, and number of seizure types, are among the other factors that significantly affected remission. CONCLUSION: A total of 45% of patients with CP and epilepsy achieved remission (with and without antiepileptics) but after a relatively long treatment duration. Remission was affected by patient- and epilepsy-related factors. More studies are required to further evaluate these factors.

Using Raman Spectroscopy in Studying the Effect of Propylene Glycol, Oleic Acid, and Their Combination on the Rat Skin.

The permeability enhancement effect of oleic acid (OA) and propylene glycol (PG) as well as their (1:1 v/v) combined mixture was studied using rat skin. The percutaneous drug administration is a challenge and an opportunity for drug delivery. To date, there is limited research that illustrates the mechanism of penetration enhancers and their combinations on the skin. This project aims to explore the skin diffusion and penetration enhancement of PG, OA, and a combination of PG-OA (1:1 v/v) on rat skin and to identify the potential synergistic effect of the two enhancers utilizing Raman spectroscopy. Dissected dorsal skin was treated with either PG or OA or their combination for predetermined time intervals after which the Raman spectra of the treated skin were collected with the enhancer. A spectrum of the wiped and the washed skin were also collected. The skin integrity was tested before and after exposure to PG. The skin histology proved that the skin integrity has been maintained during experiments and the results indicated that OA disrupted rat skin lipid as evident by changes in the lipid peak. The results also showed that PG and OA improved the diffusion of each other and created faster, yet reversible changes of the skin peaks. In conclusion, Raman spectroscopy is a potential tool for ex vivo skin diffusion studies. We also concluded that PG and OA have potential synergistic reversible effect on the skin.

Hydrogen Bonding: Between Strengthening the Crystal Packing and Improving Solubility of Three Haloperidol Derivatives.

The purpose of this study is to confirm the impact of polar functional groups on inter and intra-molecular hydrogen bonding in haloperidol (HP) and droperidol (DP) and, hence, their effects on dissolution using a new approach. To confirm our theory, a new molecule: deshydroxy-haloperidol (DHP) was designed and its synthesis was requested from a contract laboratory. The molecule was then studied and compared to DP and HP. Unlike DHP, both the HP and DP molecules have hydrogen donor groups, therefore, DHP was used to confirm the relative effects of the hydrogen donor group on solubility and crystal packing. The solid dispersions of the three structurally related molecules: HP, DP, and DHP were prepared using PVPK30, and characterized using XRPD and IR. A comparative dissolution study was carried out in aqueous medium. The absence of a hydrogen bonding donor group in DHP resulted in an unexpected increase in its aqueous solubility and dissolution rate from solid dispersion, which is attributed to weaker crystal pack. The increased dissolution rate of HP and DP from solid dispersions is attributed to drug-polymer hydrogen bonding that interferes with the drug-drug intermolecular hydrogen bonding and provides thermodynamic stability of the dispersed drug molecules. The drug-drug intermolecular hydrogen bond is the driving force for precipitation and crystal packing.

Role of Molecular Interactions for Synergistic Precipitation Inhibition of Poorly Soluble Drug in Supersaturated Drug-Polymer-Polymer Ternary Solution.

We are reporting a synergistic effect of combined Eudragit E100 and PVP K90 in precipitation inhibition of indomethacin (IND) in solutions at low polymer concentration, a phenomenon that has significant implications on the usefulness of developing novel ternary solid dispersion of poorly soluble drugs. The IND supersaturation was created by cosolvent technique, and the precipitation studies were performed in the absence and the presence of individual and combined PVP K90 and Eudragit E100. The studies were also done with PEG 8000 as a noninteracting control polymer. A continuous UV recording of the IND absorption was used to observe changes in the drug concentration over time. The polymorphic form and morphology of precipitated IND were characterized by Raman spectroscopy and scanning electron microscopy. The change in the chemical shift in solution (1)H NMR was used as novel approach to probe IND-polymer interactions. Molecular modeling was used for calculating binding energy between IND-polymer as another indication of IND-polymer interaction. Spontaneous IND precipitation was observed in the absence of polymers. Eudragit E100 showed significant inhibitory effect on nuclei formation due to stronger interaction as reflected in higher binding energy and greater change in chemical shift by NMR. PVP K90 led to significant crystal growth inhibition due to adsorption on growing IND crystals as confirmed by modified crystal habit of precipitate in the presence of PVP K90. Combination of polymers resulted in a synergistic precipitation inhibition and extended supersaturation. The NMR confirmed interaction between IND-Eudragit E100 and IND-PVP K90 in solution. The combination of polymers showed similar peak shift albeit using lower polymer concentration indicating stronger interactions. The results established the significant synergistic precipitation inhibition effect upon combining Eudragit E100 and PVP K90 due to drug-polymer interaction.

A Novel Mathematical Model for Determining Faculty Workload.

Objective. To develop a mathematical model for determining faculty workload at a college of pharmacy with a team-based learning curriculum. Methods. Using faculty provided data, our model calculated activity and weighted means in teaching, scholarship and service. Subsequently, these data were used to develop departmental and institutional workload models. Results. For the pharmaceutical and biomedical sciences department, percent faculty activity mean values were greatest for service followed by teaching and scholarship. These values in the clinical sciences department were greatest for teaching followed by service and scholarship. Overall, the institutional workload model had the largest maximum faculty activity value for teaching, followed by service and then scholarship. Conclusions. A novel faculty workload model proved to be effective in optimizing faculty workload within a college of pharmacy. Since the workload analysis, the faculty service commitment has been substantially changed, by reducing the number of committees at our institution. This type of workload analysis may particularly benefit colleges of pharmacy that employ a team based learning curriculum, with a large time commitment to teaching.

Using in situ Raman spectroscopy to study the drug precipitation inhibition and supersaturation mechanism of Vitamin E TPGS from self-emulsifying drug delivery systems (SEDDS).

We are reporting a new methodology of using Raman spectroscopy for studying the drug surfactant interactions in self-emulsifying drug delivery systems (SEDDS). The physicochemical properties of surfactants could affect the performance of drugs from lipid delivery systems. Thus the purpose of our research was to study the drug surfactant interactions on a molecular level to understand the mechanism of supersaturation and precipitation inhibition. Two surfactants, Labrasol® and Vitamin E TPGS, were used to formulate several SEDDS. The optimized SEDDS were further evaluated by a kinetic solubility study and in situ Raman spectroscopy for two model drugs. It was found that both drugs precipitated from Labrasol® SEDDS whereas TPGS was able to inhibit precipitation and achieve high drug supersaturation levels. In situ Raman spectroscopy indicated that hydrogen bonding with TPGS was the main factor responsible for inhibiting precipitation. This study was able to correlate the structure and physicochemical properties of the drugs and surfactants to their ability to prevent drug precipitation. Our study brings up a possible new systematic approach by using Raman spectroscopy in the development and optimization of lipid based delivery systems.

Amorphous stabilization and dissolution enhancement of amorphous ternary solid dispersions: combination of polymers showing drug-polymer interaction for synergistic effects.

The purpose of this study was to understand the combined effect of two polymers showing drug-polymer interactions on amorphous stabilization and dissolution enhancement of indomethacin (IND) in amorphous ternary solid dispersions. The mechanism responsible for the enhanced stability and dissolution of IND in amorphous ternary systems was studied by exploring the miscibility and intermolecular interactions between IND and polymers through thermal and spectroscopic analysis. Eudragit E100 and PVP K90 at low concentrations (2.5%-40%, w/w) were used to prepare amorphous binary and ternary solid dispersions by solvent evaporation. Stability results showed that amorphous ternary solid dispersions have better stability compared with amorphous binary solid dispersions. The dissolution of IND from the ternary dispersion was substantially higher than the binary dispersions as well as amorphous drug. Melting point depression of physical mixtures reveals that the drug was miscible in both the polymers; however, greater miscibility was observed in ternary physical mixtures. The IR analysis confirmed intermolecular interactions between IND and individual polymers. These interactions were found to be intact in ternary systems. These results suggest that the combination of two polymers showing drug-polymer interaction offers synergistic enhancement in amorphous stability and dissolution in ternary solid dispersions.

Correlation of inhibitory effects of polymers on indomethacin precipitation in solution and amorphous solid crystallization based on molecular interaction.

PURPOSE: To correlate the polymer's degree of precipitation inhibition of indomethacin in solution to the amorphous stabilization in solid state. METHODS: Precipitation of indomethacin (IMC) in presence of polymers was continuously monitored by a UV spectrophotometer. Precipitates were characterized by PXRD, IR and SEM. Solid dispersions with different polymer to drug ratios were prepared using solvent evaporation. Crystallization of the solid dispersion was monitored using PXRD. Modulated differential scanning calorimetry (MDSC), IR, Raman and solid state NMR were used to explore the possible interactions between IMC and polymers. RESULTS: PVP K90, HPMC and Eudragit E100 showed precipitation inhibitory effects in solution whereas Eudragit L100, Eudragit S100 and PEG 8000 showed no effect on IMC precipitation. The rank order of precipitation inhibitory effect on IMC was found to be PVP K90 > Eudragit E100 > HPMC. In the solid state, polymers showing precipitation inhibitory effect also exhibited amorphous stabilization of IMC with the same rank order of effectiveness. IR, Raman and solid state NMR studies showed that rank order of crystallization inhibition correlates with strength of molecular interaction between IMC and polymers. CONCLUSIONS: Correlation is observed in the polymers ability to inhibit precipitation in solution and amorphous stabilization in the solid state for IMC and can be explained by the strength of drug polymer interactions.

Studying the effect of lipid chain length on the precipitation of a poorly water soluble drug from self-emulsifying drug delivery system on dispersion into aqueous medium.

OBJECTIVE: The lipid excipients of the self-emulsifying drug delivery systems (SEDDS) could play a role in interfering with the drug precipitation to maintain its supersaturation, a step with possible major significance on the SEDDS. Thus, the effect of lipid chain length on indomethacin precipitation rate from SEDDS upon dilution was studied. METHOD: Indomethacin SEDDS were prepared using medium and long chain lipids at 5% and 13% (w/w) drug load. Two medium chain lipids Lauroglycol and Capryol, and two long chain lipids Labrafil and castor oil, were studied. The 13% w/w SEDDS were evaluated for drug release, and the physicochemical properties of the precipitated drug were characterized by PXRD, DSC, IR and Raman. KEY FINDINGS: The final optimized SEDDS consisted of Lauroglycol (lipid): Transcutol (co-solvent): Labrasol (surfactant). No precipitate was observed with long chain lipids SEDDS, whereas medium chain lipids SEDDS showed precipitation within 30 min of drug release from 13% w/w formulations. Precipitation studies showed that the medium chain lipids resulted in a modified indomethacin form possibly an ester. The ester formation signifies the interaction between indomethacin and medium chain length lipids. CONCLUSIONS: The study emphasizes the importance of lipids chain length of excipients in successful SEDDS formulations. The study provides insight into the underlying drug lipid interactions in SEDDS formulations.

Correlating the behavior of polymers in solution as precipitation inhibitor to its amorphous stabilization ability in solid dispersions.

Our major goals were to understand the mechanism of dipyridamole (DPD) precipitation inhibition in the presence of polymers and to correlate the polymers-mediated precipitation inhibition in solution to the amorphous stabilization in the solid state. A continuous UV spectrophotometer was used to monitor the DPD concentration with time in the absence and presence of different polymers. Six polymers: PVP K90, hydroxypropylmethylcellulose (HPMC), Eudragit E100, Eudragit S100, Eudragit L100, and PEG 8000 were screened at different drug-to-monomer ratios. Solid dispersions were characterized by X-ray powder diffraction and modulated differential scanning calorimetry, whereas infrared (IR) and Raman were used to investigate the possible drug-polymer interactions. Eudragit E100 and HPMC were found to delay both DPD precipitation initiation time and precipitation rates. Eudragit S100 delayed only the precipitation initiation time and PVP K90 decreased only the precipitation rates. In solid state, Eudragit S100, PVP K90, HPMC, and Eudragit L100 were effective stabilizers of the DPD solid dispersion. Eudragit S100 was found to be most effective DPD-stabilizing polymer. The IR and Raman spectra of the solid dispersion of Eudragit S100 and HPMC showed peak shift, indicating drug-polymer molecular interactions. It is concluded that the drug-polymer interaction plays a significant role in precipitation inhibition and amorphous stabilization.

Using Raman spectroscopy in tablet moisture surface analysis: tablet surface markers.

A method was developed to monitor the hydration of a tablet surface using chemical functional groups able to bind atmospheric water through H-bonding. In this study, generic oral dissolving loratadine tablets were used. These tablets have relatively high mannitol and lactose concentrations. Both mannitol and lactose have C-OH alcohol functional groups, several of which are potentially available for H-bonding with atmospheric water. The Raman intensity of the alcohol functional groups decreases upon hydration. This observation can be used to indirectly monitor water adsorbed to tablet surfaces at the alcohol sites. The hydration assay is based on the change in the Raman peak intensity of the alcohol C-OH stretching at 875.5 cm(-1). Consequently the decrease in the Raman intensity of this vibration can be used to monitor water adsorption. The Raman measurement of tablet surface water was compared to the direct moisture measurement method using a microbalance. The Raman spectroscopy is used to monitor the water that is specifically bound to the C-OH alcohol functional groups available for hydration. The microbalance was used to monitor the tablets' weight change during water adsorption and desorption. The distribution of the ratio of the Raman intensity of C-OH peak at 875.5 cm(-1) divided by the intensity of loratadine's C-Cl peak at 712.6 cm(-1) was experimentally determined to be a Gaussian distribution with a mean of 3.22+/-0.277. Raman analysis indicates that there is both tightly and loosely bound water at the tablet surface. This can be a useful technique with regard to inspecting and controlling the tablet drying process.

Quality of Progesterone Suppositories Prepared by FIRST-Progesterone Vaginal Suppository 50 Kit or Traditional Compounding Method: In Vitro Comparison.

The objective of this study was to compare the quality of progesterone suppositories prepared by using the FIRST-Progesterone Vaginal Suppository Kit to that of progesterone suppositories compounded extemporaneously by using the traditional method. The comparison parameters were weight variation, content uniformity, pH, yield, and compounding time. Each of five compounders prepared two batches, one batch using each method. The results indicate that the quality of the suppositories prepared by both methods including weight variation and content uniformity, fell within the United States Pharmacopeial accepted limits (+/- 10% of the label concentration). However, preparation time and yield were significantly different. The time spent compounding the suppositories with the FIRST-Progesterone Vaginal Suppository 50 kit was significantly shorter (five times shorter) than spent compounding the suppositories by the traditional method (P-less than 0.05). Although all compounders were advised to use an extra 10% during traditional compounding, three of the compounders failed to fill the prescribed number and ended with fewer suppositories than required. The reasons for this deficiency were either conventional mold leakage or spilling during mold filling.

Formulation and in vitro and in vivo characterization of a phenytoin self-emulsifying drug delivery system (SEDDS).

The aim of this study is to develop and characterize a self-emulsifying drug delivery system (SEDDS) of phenytoin, and to compare its relative bioavailability to a commercially available suspension. Four phenytoin SEDDS were prepared and evaluated. Following emulsification, the optimized formula was selected to have the smallest mean particle size and the highest absolute zeta potential, which should yield the formation of a stable emulsion. Its dissolution characteristics were superior to the other SEDDS formulas. In vivo and in vitro tests were run to compare the optimized formula, SEDDS II, to a commercially available Dilantin suspension. The in vitro dissolution indicated a significant improvement in phenytoin release characteristics. The in vivo study using male rats showed a clear enhancement in phenytoin oral absorption from SEDDS compared to Dilantin suspension. The area under the curve AUC((-10min-->10h)) of phenytoin after SEDDS administration increased by 2.3 times compared to Dilantin (p<0.05), and the rate of absorption of phenytoin was significantly faster from the SEDDS. The concentration after 30min (C(30min)) of SEDDS administration was 4.9 times higher than C(30min) after Dilantin administration (p<0.05). A sustained effect of phenytoin in plasma was also observed. After 12 weeks storage, SEDDS II was found to be chemically and physically stable under stressed conditions.