Chitosan-Based Microparticle Encapsulated Acinetobacter baumannii Phage Cocktail in Hydrogel Matrix for the Management of Multidrug Resistant Chronic Wound Infection

Objectives: Multi-drug resistant bacteria have been implicated in various debilitating infections that have led to life loss. This study developed an approach to tackle multidrug resistant Acinetobacter baumannii infection in a chronic wound model through A. baumannii phage encapsulation with resuspension in hydrogel. Materials and Methods: Two isolates of A. baumannii-specific lytic phases ɸAB140 and ɸAB150 alone, in combination (cocktail) encapsulated within a chitosan (CS) microparticle was suspended in CS hydrogel and evaluated for their therapeutic efficacy to ensure bacterial clearance in A. baumannii induced diabetic wound infection. Microencapsulation of the phage was carried out using ionic gelation techniques Biological characterization via cell cytoxicity, in vivo wound healing, histology and histomorphometry was carried out. Results: Two characterized A. baumannii phages (ɸAB140 and ɸAB150), specific to twenty A. baumannii isolates, were isolated. The encapsulated CS microparticle hydrogel exhibited a pH of 5.77 ± 0.05. The wound size reduction was most pronounced in formulation C2, which showed statistically significant wound seize reduction on days 4 and 7, 56.79 ± 2.02% and 62.15 ± 5.11%, respectively. The optimized concentration of C2 was not toxic to the cells as it adequately supported cell growth with a proliferation rate of 215 ± 7.89% compared to control (107.32 ± 4.55%). Conclusion: Microparticle carrier technology was used to show the lytic activity against multi drug-resistant A. baumannii. In vivo results showed significant wound size reduction that was most pronounced in formulation C2 on day 4.

Mucoadhesive Microspheres of Maraviroc and Tenofovir Designed for Pre-Exposure Prophylaxis of HIV-1: An in vitro Assessment of the Effect on Vaginal Lactic Acid Bacteria Microflora.

PURPOSE: To formulate and evaluate microspheres of the antiretroviral drugs maraviroc and tenofovir intended for a candidate vaginal microbicide and assess its effect on the vaginal lactic acid bacteria microflora. METHODS: Ionic gelation technique was used to formulate maraviroc and tenofovir microspheres with subsequent characterization. The effect of varying concentrations of the polymer, crosslinking agent and the curing time on the outcome variables viz: particle size, mucoadhesion and encapsulation efficiency were investigated. Lactic acid bacteria were isolated from the vagina of healthy women using standard microbiologic methods. The analysis of their 16S rRNA sequence data identified Lactobacillus fermentum and Enterococcus faecalis strains which were assigned GenBank accession numbers. The efficacy of the microspheres on HIV-1BaL strain was evaluated using TZM-bl indicator cells. RESULTS: The optimal maraviroc and tenofovir microspheres had particle sizes of (434.82 µm and 456.18 µm), mucoadhesion of (93.3% and 90%) and encapsulation efficiency (92.80% and 78.9%) respectively. Maraviroc release kinetics followed a zero-order model and tenofovir was released via Higuchi model. The assay of a 1 mg/mL suspension of the microspheres on the strains of Lactobacillus fermentum and Enterococcus faecalis showed a viability of 93.9% and 89.7%, respectively. There was a statistically significant difference between the mean absorbance readings of the test agent and that of the positive control (P = 0.001). The microspheres elicited a progressive decline in HIV infectivity until at a concentration of 1 µg/mL. CONCLUSION: The antiretroviral drugs loaded in the microspheres, had good mucoadhesion which is a potential for prolonged residence time in the vagina. The antiretroviral drugs were adequately released from the microspheres and showed efficacy against the HIV-1 BaL virus strain. There was no significant disruption in the growth of the lactic acid bacteria which constitute valuable bacteria microflora of the vagina.

Encapsulation of Andrographolide in poly(lactide-co-glycolide) Nanoparticles: Formulation Optimization and in vitro Efficacy Studies.

Andrographolide is a potential chemopreventive and chemotherapeutic agent that suffers from poor aqueous solubility. Encapsulation in poly(lactide-co-glycolide) (PLGA) nanoparticles can overcome solubility issues and enable sustained release of the drug, resulting in improved therapeutic efficacy. In this study, andrographolide was encapsulated in PLGA nanoparticles via emulsion solvent evaporation technique. Effect of various formulation parameters including polymer composition, polymer molecular weight, polymer to drug ratio, surfactant concentration and the organic solvent used on nanoparticle properties were investigated. A selected formulation was used to determine the effect of encapsulation in nanoparticles on andrographolide's in vitro anticancer efficacy. Nanoparticles formulated using a polymer with 85:15 lactide to glycolide ratio and ethyl acetate as the organic solvent were found to be optimal based on average hydrodynamic particle size (135 ± 4 nm) and drug loading (2.6 ± 0.6%w/w). This formulation demonstrated sustained release of andrographolide over 48 h and demonstrated significantly greater in vitro anticancer efficacy compared to free drug in a metastatic breast cancer cell line. These results suggest that additional, more in-depth efficacy studies are warranted for the nanoparticle formulation of andrographolide.

Enzyme Responsive Vaginal Microbicide Gels Containing Maraviroc and Tenofovir Microspheres Designed for Acid Phosphatase-Triggered Release for Pre-Exposure Prophylaxis of HIV-1: A Comparative Analysis of a Bigel and Thermosensitive Gel.

The challenges encountered with conventional microbicide gels has necessitated the quest for alternative options. This study aimed to formulate and evaluate a bigel and thermosensitive gel, designed to combat the challenges of leakage and short-residence time in the vagina. Ionic-gelation technique was used to formulate maraviroc and tenofovir microspheres. The microspheres were incorporated into a thermosensitive gel and bigel, then evaluated. Enzyme degradation assay was used to assess the effect of the acid phosphatase enzyme on the release profile of maraviroc and tenofovir microspheres. HIV efficacy and cytotoxicity of the microspheres were assessed using HIV-1-BaL virus strain and HeLa cell lines, respectively. Maraviroc and tenofovir release kinetics followed zero-order and Higuchi model kinetics. However, under the influence of the enzyme, maraviroc release was governed by first-order model, while tenofovir followed a super case II transport-mechanism. The altered mode of release and drug transport mechanism suggests a triggered release. The assay of the microspheres suspension on the HeLa cells did not show signs of cytotoxicity. The thermosensitive gel and bigel elicited a progressive decline in HIV infectivity, until at concentrations of 1 µg/mL and 0.1 µg/mL, respectively. The candidate vaginal gels have the potential for a triggered release by the acid phosphatase enzyme present in the seminal fluid, thus, serving as a strategic point to prevent HIV transmission.

Effect of pore size and morphology of activated charcoal prepared from midribs of Elaeis guineensis on adsorption of poisons using metronidazole and Escherichia coli O157:H7 as a case study.

Agricultural waste obtained from Elaeis guineensis mid ribs can provide a veritable source of materials which can be used as precursor materials for the production of pharmaceutical grade activated charcoal. The pore size and surface morphology of activated charcoal defines the types of molecules that could be adsorbed unto it, as surface morphology plays a significant role in determining the surface availability and areas of adsorption. The activated charcoal samples prepared from Elaeis guineensis via either physical or chemical activation was characterized via surface area using the BET method and subsequently pore structure and size analyzed by scanning electron microscopy (SEM). Physically activated Elaeis guineensis fronds activated with nitrogen gas had wide spread microporosity with micropore volume of 0.232 cc/g compared to the chemically activated with 1M and 3M phosphoric acid respectively. The commercial activated charcoal/metronidazole combination in the in vitro-pharmacodynamic model reflected no re-growth after 4 hours, however for charcoal formulated from Elaeis guineensis via chemical activation with 3M phosphoric acid and metronidazole no regrowth was seen at the second hour and this was maintained throughout the duration of the experiment. Increased macroporosity enhanced bacterial adsorption and this was further facilitated by the presence of antibacterial metronidazole in the in vitro pharmacodynamic model. Activated charcoal produced from agricultural waste obtained from Elaeis guineensis dried mid ribs consisting of increased macroporosity with mixed meso/micro porosity and antibacterial metronidazole form the best model for bacterial adsorption and will be useful in the treatment of diarrhea caused by E. coli O157:H7.

Analysis of metronidazole in equine plasma using liquid chromatography/tandem mass spectrometry and high-resolution accurate mass spectrometry.

RATIONALE: Treatment of racehorses with bicarbonate solutions to manage acidosis and muscle cramps prior to competition is banned in Pennsylvania (PA). Use of excess bicarbonate in horses causes diarrhea, requiring treatment with an antibiotic such as metronidazole (MTNZ). At present no method exists for detecting MTNZ in equine plasma. Thus, a liquid chromatography/tandem mass spectrometry (LC/MS/MS) method for the detection, quantification and confirmation of MTNZ was developed. METHODS: The analyte was recovered from plasma by liquid-liquid extraction using methyl tert-butyl ether and separated on an ACE® C18 column with its guard column. The mobile phase comprised a mixture of 5 mM ammonium formate (pH 3.5) and acetonitrile (60:40; v/v). Mass analysis was performed on an LTQ XL linear ion trap mass spectrometer in positive electrospray ionization mode while accurate mass determination was also performed in positive electrospray ionization mode using high-resolution accurate mass spectrometry (HRAMS). RESULTS: The limit of detection (LOD), limit of confirmation (LOC) and lower limit of quantification (LLOD) were 1, 2 and 50 ng/mL, respectively. The analyte in plasma was stable at -20 and -70°C for 28 days, as well as for 24 h at 20°C in the autosampler. The percentage coefficients of variation (% CV) for the intra-day and inter-day precision for the LLOQ were 5.1:3.68 and 13.21:9.95, respectively, while the intra-day accuracy was from 98.71 to 101.57% and that of the inter-day was from 88.64 to 96.6%. The matrix effect was between 9 and 24%. The precursor → product ion transition m/z 172 → 128, a retention time of 2.92 min and the accurate mass of the [M+H](+) ion of the analyte (m/z 172.0173) were used as criteria for confirmation of the presence of MTNZ in equine plasma. CONCLUSIONS: The method is highly sensitive and selective for the detection, identification and confirmation of MTNZ in equine plasma. Thus, illegal use of MTNZ in racehorses can be routinely monitored within the US State of Pennsylvania. The method is fast, sensitive, reproducible, and reliable.

Prescribing Patterns and Perceptions of Health Care Professionals About Rational Drug use in a Specialist Hospital Clinic.

Irrational drug use is associated with adverse consequences including drug resistance and avoidable adverse drug reactions. Studies of rational drug use in psychiatric facilities are scanty. This study evaluated prescription practices and perception of health care professionals regarding causes of irrational drug use. A retrospective study conducted at the outpatient clinic of Federal Neuropsychiatric Hospital, Yaba, Lagos. Data on drug use indicators were analyzed. A cross-sectional assessment of perception of prescribers and dispensers regarding rational drug use was conducted. A total of 600 prescriptions were analyzed. Mean number of drugs per encounter was 3.5 and percentage generic prescribed was 58.5%. Poly-pharmacy (P=0.024, 95% CI=1.082-1.315) and non-generic prescribing (P=0.032, 95% CI=1.495-1.821) were significantly associated with young prescribers. Factors associated with irrational drug use include demand from patients, patients' beliefs about injection drugs and influence of pharmaceutical sale representatives. Certain aspect of prescribers indicators are still poor in the hospital studied. Health care professionals identified possible associated factors for irrational drug use. Concerted efforts are required to ensure rational drug use especially in psychiatric facilities in Nigeria.

Formulation of quinine suppository for initiation of early treatment of malaria - a preliminary study.

Background: In the management of malaria, there is the need for early initiation of treatment. An antimalarial drug for home use must be easy to administer, safe, effective and affordable. Parenteral quinine is the gold standard for treatment of severe malaria. A rectal formulation of quinine will therefore serve the purpose of early initiation of care in patients that lack easy access to medical centers. The main objective of this preliminary work was to develop a quinine suppository with adequate release properties that also meets the dual conditions of affordability and ease of administration. Materials and Methods: Cocoa butter and Fattibase™ were used in the preparation of suppositories containing 200 mg quinine bisulphate. The release profiles of formulations with varying concentrations of polysorbate 80 (0 - 5%) were evaluated by in vitro dissolution in pH 8 buffer medium. Results: The addition of polysorbate 80 improved the release of quinine significantly at 2 and 5%. Cocoa butter suppository with 1% polysorbate 80 released 73.6 mg quinine bisulphate in 1 hr while release from suppositories with 2% and 5% surfactant was higher. Fattibase™ suppositories had better release profiles than cocoa butter formulations. The formulation with 5% polysorbate 80 released 170 mg quinine in 1 hr. Formulations with the two bases released quinine in adequate quantities for the management of malaria. Conclusions: The particle size of quinine is an important factor affecting the physical appearance and drug release from the suppository. The Fattibase™ suppositories were more stable but cost five times the price of the cocoa butter formulations. The cocoa butter formulations, however, still released quinine in sufficient quantities for the management of malaria. Cocoa butter formulations will be more affordable in resource-limited malaria-endemic regions of the world.

The antiplasmodial effect of the extracts and formulated capsules of Phyllanthus amarus on Plasmodium yoelii infection in mice.

OBJECTIVE: To investigate the antiplasmodial activity of the extracts of Phyllanthus amarus (P. amarus) on Plasmodium yoelii (P. yoelii) (a resistant malaria parasite strain used in animal studies) infection in mice. METHODS: The aqueous and ethanol extracts of the whole plant of Phyllanthus amarus was administered to Swiss albino mice at doses of 200 mg/kg/day, 400 mg/kg/day, 800 mg/kg/day and 1600 mg/kg/day and the prophylactic and chemotherapeutic effect of the extracts against P. yoelii infection in mice was investigated and compared with those of standard antimalaria drugs used in the treatment of malaria parasite infection. Acute toxicity test was carried out in mice to determine the safety of the plant extract when administered orally. RESULTS: The results showed that the extracts demonstrated a dose-dependent prophylactic and chemotherapeutic activity with the aqueous extracts showing slightly higher effect than the ethanol extract. The antiplasmodial effects of the extracts were comparable to the standard prophylactic and chemotherapeutic drugs used in chloroquine resistant Plasmodium infection although the activity depended on the dose of the extract administered. The extracts showed prophylactic effect by significantly delaying the onset of infection with the suppression of 79% at a dose of 1600 mg/kg/day. CONCLUSIONS: The results obtained indicate that the extracts of the whole plant of P. amarus possess repository and chemotherapeutic effects against resistant strains of P. yoelii in Swiss albino mice. The findings justify the use of the extract of P. amarus in traditional medicine practice, for the treatment of malaria infections.