Formulation and Evaluation of Microspheres Based on Gelatin-Mucin Admixtures for the Rectal Delivery of Cefuroxime Sodium

Purpose: Swellable microspheres based on polymers or their admixtures are frequently employed as drug delivery systems to achieve a controlled release and site-specific targeting of the incorporated drug. The objective of the present study was to enhance the rectal delivery of cefuroxime sodium by entrapping it into water-swellable gelatin-mucin microspheres. Method: Cefuroxime sodium-loaded microspheres containing admixtures of gelatin and porcine mucin were prepared via an emulsification-crosslinking technique. The drug entrapment efficiency of the microspheres was evaluated in citrate/phosphate buffer (pH 7.4) while the swelling properties was evaluated in both simulated gastric fluid (SGF) without pepsin and simulated intestinal fluid (SIF) without pancreatin (pH 1.2). Release of cefuroxime sodium from the microspheres was evaluated in vitro in SIF and further evaluated in vivo after rectal administration to male Wistar rats. Result: Results obtained showed that a high entrapment efficiency, most notably manifested in microspheres formulated with equal portions of gelatin and mucin, led to a high release (up to 85 %) and also a high bioavailability of the incorporated drug. Formulations based on varying portions of gelatin and mucin also showed high drug loading efficiency which also resulted in high drug release in SIF within 3 h. Drug release from the different formulations was observed to be rapid and generally showed a biphasic pattern. The mean AUC was shown to be formulation-dependent with values of 168±1.93μg.h/ml for the control, 262±3.47 μg.h/ml for microspheres based on gelatine only and 328±2.55 μg.h/ml for microspheres formulated with equal parts of gelatin and mucin. Conclusion: The inclusion of S-mucin in the composition of the microspheres has an enhancer effect on the release and rectal bioavailability of cefuroxime sodium which may be exploited in the design of a rectal delivery system of the drug

Formulation and Evaluation of Glutaraldehyde-Crosslinked Chitosan Microparticles for the Delivery of Ibuprofen

Purpose: Toformulate glutaraldehyde-cross-linked chitosan-based microparticles and evaluate its suitability for the delivery of ibuprofen, a BCS class II drug. Methods: Ibuprofen-loaded chitosan microparticles were prepared by emulsification-cross-linking technique using glutaraldehyde saturated toluene (GST) as the cross-linking agent. The microparticles were characterized with respect to morphology, particle size, microparticle yield and entrapment efficiency. The swelling behaviour of the particles and ibuprofen release were assessed in both simulated gastric fluid (SGF) without pepsin (pH 1.2) and simulated intestinal fluid (SIF) without pancreatin (pH 7.4). Results: Discrete and free-flowing microparticles of size range 100.05 ± 8.82 to 326.70 ± 10.43 μm were obtained. The microparticles had a high yield (69.2 to 99.2 %) and exhibited greater water sorption capacity in SIF (122.2 %) than in SGF (60 %). Furthermore, the microparticles cross-linked with 10 ml of GST entrapped the highest amount of drug (23.32 ± 0.97 %) while those cross-linked with 25 ml GST had the highest yield of the microparticles (99.19 % ), and highest water sorption in SIF (122.2 %). Up to 93.6 % of the entrapped drug was released in SIF from microparticles cross-linked with 25 ml of GST. Drug release from microparticles cross-linked with 20 and 30 ml each of GST showed a biphasic pattern. Conclusions: Entrapment of ibuprofen in glutaraldehyde-cross-linked chitosan microparticles can be exploited to target and control the release of the drug and possibly reduce its gastro-erosive side effects

In vitro evaluation of the antimicrobial potential of root extracts Ofanacardium occidentale linn. Against urogenital clinical pathogens

Recently, there is a growing awareness of the role of plant-derived natural products in modern medicine. This study brought forth the case of anti-microbial properties of root extracts of Anacadiumoccidentale Linn (Cashew) against urogenital clinical pathogens. The clinical pathogens (Candidaalbicans, Escherichia coli and Staphylococcus aureus) were isolated from body fluid (High Vaginal Swab, (HVS), urine, semen EndoCervical Swab (ECS), Urethral Swab, US, and blood) of patients attending outpatient clinic of Bishop Shanahan Hospital, Nsukka. Protocols for ethical clearance were duly observed, and first person informed consent was obtained from each patient before collection of the body fluid. The A. occidentale roots were washed, room-dried and pulverized with laboratory hammer mill to a fine texture/size of 60 micron size. Aqueous extracts of the plant was obtained by hot water maceration for 24 h, and strained with clean muslin clothes. Methanol or n-hexane extracts were obtained by soxhlet extraction technique following standard procedures. The extracts were concentrated using rotary evaporator under vacuum. Antimicrobial properties of the extracts against the clinical isolates were investigated using the agar well dilution technique. Minimum Inhibitory Concentration (MIC) of each extract against the clinical isolates was determined using agar dilution technique. Results of phytochemical screening showed that the extracts contained alkaloids, glycosides, resins, tannins, flavonoids, terpenoids, steroids, saponins, carbohydrates, proteins and lipids. The mean of the methanol extracts of A. occidentaleoil against Candida albicans, Escherichia coli and Staphylococcus aureus were 13.3 μg/ml, 13.5 μg/ml, 9.8 μg/ml respectively. The urogenital clinical pathogens were sensitive to the effects of methanol extracts of A. occidentale root. The results justify the folkloric ethno-medicinal uses of the plants in the treatment of tropical diseases. This could be attributed to the presence of natural products seen in the phytochemical screening. Keywords: antimicrobial, Anacardium occidentale, urogenital, clinical isolates, MI

Revalence of Metallo- β- Lactamases (MBLs) in carbapenem non-susceptible Escherichia coli isolated from major meat sources

Metallo-β-lactamases (MBLs) are broad spectrum β-lactam degrading enzymes with the „last resort antibiotics‟, carbapenems, in their hydrolytic spectrum. Their emergence and rapid global spread have become a threat to the antibiotics armamentarium. This study was conducted to determine the prevalence of carbapenem non-susceptible Escherichia. coli isolates harbouring MBL enzymes in major meat sources within Nsukka, Enugu State, Nigeria. A total of 250 randomized non-duplicate rectal swab samples of birds and cattle at different poultry and ranches, as well as meat vendors‟ tables were cultured for E. coli isolates. Susceptibility of the properly characterized E. coli isolates to carbapenems and other commonly administered antibiotics was evaluated using disk diffusion method according to Clinical & Laboratory Standard Institute (CLSI) 2018 guideline. MBL production and Multiple Antibiotics Resistance (MAR) Index of the isolates were determined using standard formula and Combined Disc Test (CDT) technique respectively. A total of 138 E. coli were identified, out of which 57% (n = 78) were resistant to carbapenems, while 60% (n = 47) of the carbapenem-non-susceptible isolates were phenotypically confirmed as MBLs-producers. Their MAR Indices and level of resistance to other antibiotics ranged from 0.2 to 1.0 and 20 to 100% respectively. The work identified high levels of carbapenem resistance mediated by MBL enzymes in meat sources among occupants of Nsukka metropolis, necessitating an urgent need for sensitization of livestock and meat handlers, as well as the institutionalization and implementation of proper infection control measures to contain their spread. Further molecular studies are also needed for the full characterization of other carbapenem resistance mechanisms that could be associated. Keywords: E. coli, Carbapenem, Resistance, MBL, CDT, CLS