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BACKGROUND: Africa's economic transformation relies on a radical transformation of its higher education institutions. The establishment of regional higher education Centres of Excellence (CoE) across Africa through a World Bank support aims to stimulate the needed transformation in education and research. However, excellence is a vague, and often indiscriminately used concept in academic circles. More importantly, the manner in which aspiring institutions can achieve academic excellence is described inadequately. The main objective of this paper is to describe the core processes of excellence as a prerequisite to establishing academic CoE in Africa. METHODS: The paper relies on our collaborative discussions and real-world insight into the pursuit of academic excellence, a narrative review using Pubmed search for a contextual understanding of CoEs in Africa supplemented by a Google search for definitions of CoEs in academic contexts. RESULTS: We identified three key, synergistic processes of excellence central to institutionalizing academic CoEs: participatory leadership, knowledge management, and inter-disciplinary collaboration. (1) Participatory leadership encourages innovations to originate from the different parts of the organization, and facilitates ownership as well as a culture of excellence. (2) Centers of Excellence are future-oriented in that they are constantly seeking to achieve best practices, informed by the most up-to-date and cutting-edge research and information available. As such, the process by which centres facilitate the flow of knowledge within and outside the organization, or knowledge management, is critical to their success. (3) Such centres also rely on expertise from different disciplines and 'engaged' scholarship. This multidisciplinarity leads to improved research productivity and enhances the production of problem-solving innovations. CONCLUSION: Participatory leadership, knowledge management, and inter-disciplinary collaborations are prerequisites to establishing academic CoEs in Africa. Future studies need to extend our findings to understand the processes key to productivity, competitiveness, institutionalization, and sustainability of academic CoEs in Africa.
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Becas , Liderazgo , África , Humanos , Encuestas y Cuestionarios , UniversidadesRESUMEN
Medicinal plants have been traditionally used to treat cancer in Ethiopia. However, very few studies have reported the in vitro anticancer activities of medicinal plants that are collected from different agro-ecological zones of Ethiopia. Hence, the main aim of this study was to screen the cytotoxic activities of 80% methanol extracts of 22 plants against human peripheral blood mononuclear cells (PBMCs), as well as human breast (MCF-7), lung (A427), bladder (RT-4), and cervical (SiSo) cancer cell lines. Active extracts were further screened against human large cell lung carcinoma (LCLC-103H), pancreatic cancer (DAN-G), ovarian cancer (A2780), and squamous cell carcinoma of the esophagus (KYSE-70) by using the crystal violet cell proliferation assay, while the vitality of the acute myeloid leukemia (HL-60) and histiocytic lymphoma (U-937) cell lines was monitored in the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) microtiter assay. Euphorbia schimperiana, Acokanthera schimperi, Kniphofia foliosa, and Kalanchoe petitiana exhibited potent antiproliferative activity against A427, RT-4, MCF-7, and SiSo cell lines, with IC50 values ranging from 1.85 ± 0.44 to 17.8 ± 2.31 µg/mL. Furthermore, these four extracts also showed potent antiproliferative activities against LCLC-103H, DAN-G, A2780, KYSE-70, HL-60, and U-937 cell lines, with IC50 values ranging from 0.086 to 27.06 ± 10.8 µg/mL. Hence, further studies focusing on bio-assay-guided isolation and structural elucidation of active cytotoxic compounds from these plants are warranted.
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Medicinas Tradicionales Africanas/métodos , Extractos Vegetales/análisis , Plantas Medicinales/química , Antineoplásicos/aislamiento & purificación , Antineoplásicos/metabolismo , Antineoplásicos Fitogénicos/aislamiento & purificación , Antineoplásicos Fitogénicos/metabolismo , Línea Celular Tumoral/efectos de los fármacos , Etiopía , Humanos , Concentración 50 Inhibidora , Extractos Vegetales/químicaRESUMEN
BACKGROUND: The interplay between numerous factors, including the size, shape, coating, surface charge and composition of particles is known to affect the pharmacokinetics and biodistribution of superparamagnetic iron oxides (SPIOs). This makes understanding the role of each factor independently quite challenging. METHODS: In the present study, the in vivo magnetic resonance imaging (MRI), biodistribution and hepatic clearance evaluations of two SPIOs Formulations A and B developed from â¼13.5 nm hydrophobic oleic acid stabilized monodisperse magnetite nanocrystals core and lipid-based amphiphilic stabilizers were performed using a prototype benchtop MR imager (22 MHz) and pulsed nuclear magnetic resonance (NMR) system (20 MHz), respectively. Formulation A was composed of mPEG-2000-DSPE and Formulation B was composed of Phospholipon-100H, sucrose ester M-1695 and Cremophor RH-40. RESULTS: The in vivo MRI investigations showed that both formulations were safe and effective as potential liver MR contrast agents with sustained liver contrast for at least seven days. In addition, ex vivo relaxometric investigations revealed that the formulations predominantly distribute to the liver and spleen following I.V. injection. The hepatic clearance kinetics determined based on the relaxometric quantification method indicated that both formulations exhibited a biphasic clearance process with a slow terminal clearance half-life of 11.5 and 12.7 days, respectively, for Formulations A and B. CONCLUSIONS: The results of this study showed the potential biomedical applications of the investigated magnetopharmaceutical formulations as MRI contrast agents.
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Imagen por Resonancia Magnética/métodos , Nanopartículas de Magnetita/química , Ácido Oléico/química , Ácido Oléico/farmacocinética , Agua/química , Agua/metabolismo , Animales , Química Farmacéutica , Evaluación Preclínica de Medicamentos/métodos , Femenino , Ratones , Ratones Endogámicos BALB C , Distribución Tisular/efectos de los fármacos , Distribución Tisular/fisiologíaRESUMEN
BACKGROUND: Novel aqueous nano-scaled formulations were developed for hydrophobic oleic acid stabilized monodisperse superparamagnetic magnetite nanocrystals. METHODS: In the study, single and mixed lipid amphiphiles based on Cremophor RH-40 (Crem-RH-40), Solutol HS-15 (Sol-HS-15), Phospholipon-100H (PL-100H) and sucrose ester M-1695 (SE-M-1695) were employed at varying concentrations. Isotonicity and physiological pH adjustments were achieved by using 5% w/v mannitol in 10 mM pH 7.4 phosphate buffer. Mannitol also served as lyoprotectant for the freeze drying of selected formulation. The developed formulations were characterized by photon correlation spectroscopy (PCS) and asymmetric flow field flow fractionation methods for their size and size distributions and morphologies were examined by transmission electron microscopy (TEM). Moreover, the potential magnetic resonance imaging (MRI) contrast agent application of a selected formulation was investigated by (1)H-NMR relaxometric measurements. RESULTS: The results showed that stable formulations of the nanocrystals with hydrodynamic diameters generally below 100 nm were obtained. Among the developed formulations, the one prepared with 0.75% Crem-RH-40, 0.5% PL-100H and 0.25% SE-M-1695 had a mean hydrodynamic diameter of ~64 nm and zeta potential of -20 mV. This formulation exhibited low degree of aggregation, high level of incorporation of magnetite nanocrystals and very good stability profile over a period of 6 months. In addition, it showed transverse and longitudinal relaxivities of 221.8 and 32.1 s(-1)·mM(-1), respectively with r(2)/r(1) ratio of 6.9. CONCLUSION: This study revealed that mixed lipid-based amphiphiles allow stable aqueous formulations of the normally challenging hydrophobic magnetite nanocrystals with potential in vivo MRI contrast applications.
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Compuestos Férricos/química , Nanopartículas/química , Ácido Oléico/química , Medios de Contraste/química , Interacciones Hidrofóbicas e Hidrofílicas , Campos Magnéticos , Imagen por Resonancia Magnética/métodos , Tamaño de la Partícula , Solventes/químicaRESUMEN
Macrolide drugs are among the broad-spectrum antibiotics that are considered as "miracle drugs" against infectious diseases that lead to higher morbidity and mortality rates. Nevertheless, their effectiveness is currently at risk owing to the presence of devastating, antimicrobial-resistant microbes. In view of this challenge, nanotechnology-driven innovations are currently being anticipated for promising approaches to overcome antimicrobial resistance. Nowadays, various nanostructures are being developed for the delivery of antimicrobials to counter drug-resistant microbial strains through different mechanisms. Metallic nanoparticle-based delivery of macrolides, particularly using silver and gold nanoparticles (AgNPs & AuNPs), demonstrated a promising outcome with worthy stability, oxidation resistance, and biocompatibility. Similarly, macrolide-conjugated magnetic NPs resulted in an augmented antimicrobial activity and reduced bacterial cell viability against resistant microbes. Liposomal delivery of macrolides also showed favorable synergistic antimicrobial activities in vitro against resistant strains. Loading macrolide drugs into various polymeric nanomaterials resulted in an enhanced zone of inhibition. Intercalated nanomaterials also conveyed an outstanding macrolide delivery characteristic with efficient targeting and controlled drug release against infectious microbes. This review abridges several nano-based delivery approaches for macrolide drugs along with their recent achievements, challenges, and future perspectives.
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Nanopartículas del Metal , Nanoestructuras , Oro , Macrólidos/farmacología , Antibacterianos/farmacologíaRESUMEN
Background: Among all the pharmaceutical dosage forms, tablets are still the most preferred and the most commonly used option because of their advantages. The direct compression method of tablet preparation exempts several steps needed in the granulation method. Therefore, the pursuit of better direct compression tablet excipients is evident in contemporary research endeavors. Pregelatinized Taro Boloso-I starch has comparable flow properties and higher compressibility and compactibility than Starch 1500®. However, there is no evidence in the literature regarding the lubricant sensitivity and dilution potential of pregelatinized Taro Boloso-I starch. This study was aimed at performing the in vitro evaluation of paracetamol tablets prepared using pregelatinized Taro Boloso-I starch as a direct compression excipient using paracetamol as a model drug. Methods: Taro Boloso-I starch was pregelatinized, and its properties including amylose to amylopectin ratio, densities, flow properties, swelling power, water solubility index, particle morphology, moisture content, and moisture sorption profile were evaluated. Furthermore, the lubricant sensitivity test, dilution potential study, and compatibility test with the paracetamol drug using ATR spectroscopy were performed. The properties of the directly compressed tablets prepared accordingly were evaluated. The majority of evaluations were performed in comparison with Starch 1500®. Results and Discussion. PGTBIS had a significantly lower amount of amylose than Starch 1500®. In the ATR-IR spectra of the mixture of the paracetamol and pregelatinized PGTBIS, all the major absorbance peaks of the drug were maintained indicating the absence of chemical modifications. PGTBIS showed better flow properties than Starch 1500®. The modified starch was shown to withstand magnesium stearate up to 0.5% concentration. Conclusion: PGTBIS could accommodate higher drug cargo than Starch 1500® with acceptable tablet properties. Accordingly, PGTBIS starch could be taken as a potential direct compression excipient.
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Ethiopia registers 77,352 new cases of cancer and 51,865 deaths every year, and the number is showing an increasing trend year to year. Despite the importance of providing palliative care, the country has a long way to go to match the needs of and provide relief for patients with cancer. The promotion and expansion of palliative care services is challenged by a number of problems, among which lack of access to pain-relieving medicine is one of, if not the main, problems raised by health professionals and by various parties involved in health care. Oral morphine is effective and the preferred pain-relieving medicine with tolerable side effects, especially when given by titrating the dose. However, Ethiopia is facing a shortage of oral morphine in health-care facilities and other places where the product is needed. Unless an immediate solution is sought to address the inaccessibility of this medicine, the problem of palliative care will be pronounced and the suffering of patients will continue.
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Background: Vernonia auriculifera Hiern (Asteraceae) is among Ethiopian herbal medicines that are traditionally used to treat skin and gastrointestinal cancers. In this study, the chemopreventive potential of Vernonia auriculifera leaf extract in dimethylhydrazine (DMH)-induced colorectal carcinogenesis in rats was investigated. Methods: Rats were assigned to nine groups (normal, positive, and negative control groups, and three pre- and three post-initiation groups). Except for the normal control group (administered with 1 mL/100 g distilled water), the remaining eight groups were given DMH (20 mg/kg) intraperitoneally (ip) for 15 consecutive weeks to induce colorectal tumours. The extract was given orally to the pre-initiation and post-initiation groups at doses of 100, 200, and 400 mg/kg before and after the induction of cancer, respectively. The positive control group was treated with aspirin (60 mg/kg/day) orally for the whole experimental period. Parameters including body weight, average tumour number, size, progression, incidence, total cholesterol, serum total protein, and triglyceride levels were determined. The cytotoxic activity of the extract in Caco-2 cells was evaluated using the MTT assay, and the antioxidant activity of the extract was also assessed using 2.2-diphenyl-1-picrylhydrazine (DPPH) and reducing power methods. Moreover, total phenol and flavonoid contents were determined using appropriate methods. Results: Rats treated with the extract showed a lower incidence of up to 50% in the pre-initiation higher dose, average number (p<0.05),and size (p<0.05) of tumours compared to untreated rats. It also inhibited colorectal cancer-associated increases in serum total cholesterol and triglycerides. The extract's IC50 value in the MTT assay was found to be higher than 200 µg/mL. The extract had an IC50 of 74.88 ± 0.86 µg/mL and 84.69 ± 2.02 µg/mL in the reducing power and DPPH assays, respectively. Total flavonoid and phenol contents were 14.51 ± 0.41 mg quercetin acid equivalent/gm and 47.37 ± 0.72 mg gallic acid equivalent/gm of the crude extract, respectively. Conclusion: The findings collectively indicated that the leaves of V. auriculifera possess chemopreventive activity, probably mediated through antioxidant mechanisms, which supports the traditional claim.
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Local production of generic medicines in developing countries has a critical role to meet public health needs by ensuring the availability of essential medicines and providing patients' relief from the burden of unaffordable medical bills. Compliance with bioequivalence (BE) requirements increase the quality and competitiveness of generic drugs regardless of the source. In this regard, a regional BE center has been established in Addis Ababa, Ethiopia to serve the needs of Ethiopia and neighbouring countries. The present study aimed to assess the knowledge and perceptions of health professionals working in Addis Ababa regarding local production and BE studies of generic medicines. A cross-sectional survey was employed and physician participants working at public hospitals and pharmacists from various practice settings were selected using convenient sampling technique. Data was collected using self-administered structured questionnaire. Descriptive statistics was used to summarize the data and multinomial logistic regression analyses was used to assess predictors of health professionals' perception towards the source of drugs. Statistically significant association was declared at p-value < 0.05. A total of 416 participants responded and 272 (65.4%) of them were male. Nearly half of the study participants (n = 194) preferred the imported products. Compared to physicians, participants with diploma (AOR = 0.40; 95%CI: 0.18-0.91, p = 0.028) and bachelor degree and above holders (AOR = 0.32; 95%CI: 0.15-0.68, p = 0.003) in pharmacy were more likely to prefer locally produced products. Participants who practiced in pharmaceutical industries (AOR = 0.40, 95%CI: 0.22-0.77, p = 0.006) preferred locally manufactured products as compared to those practicing in the hospital. While a majority (321, 77.2%) believed in the advantages of doing BE studies locally, only 106 (25.5%) recognized that local pharmaceutical manufacturers did not implement BE studies for their generic products and lack of enforcement by the national regulatory body was raised as a reason for not conducting BE studies by most of the participants (67.9%). The present study revealed a modest preference by physicians and pharmacy professionals towards locally produced products. Majority of participants supported the idea of doing BE studies locally. However, manufacturers and regulators should devise ways to increase health professionals' confidence in local products. Strengthening local BE study capacity is also highly recommended.
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Farmacia , Médicos , Humanos , Masculino , Femenino , Estudios Transversales , Etiopía , Medicamentos Genéricos/uso terapéutico , Equivalencia TerapéuticaRESUMEN
Fungal infections are human infections that topically affect the skin, mucous membranes, or more serious, invasive, and systemic diseases of the internal organs. The design and advancement of the formulation and approach of administration for therapeutic agents depend on many variables. The correlation between the formulations, mode of administration, pharmacokinetics, toxicity and clinical indication must be thoroughly studied for the successful evolution of suitable drug delivery systems. There are several NP formulations that serve as good delivery approaches for antifungal drugs. This paper covers various groups of nanoparticles utilized in antifungal drug delivery, such as phospholipid-based vesicles (nanovesicles), non-phospholipid vesicles, polymeric nanoparticles, inorganic nanoparticles and dendrimers, whereby their advantages and drawbacks are emphasized. Many in vitro or cell culture studies with NP formulations achieve an adequate high drug-loading capacity; they do not reach the clinically significant concentrations anticipated for in vivo studies. Because of this, the transfer of these nano-formulations from the laboratory to the clinic could be aided by focusing studies on overcoming problems related to nanoparticle stability, drug loading, and high production and standardization costs.
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The use of starch, a natural polymeric material, and derivatives thereof is based on its adhesive, thickening, gelling, swelling, and film-forming properties, as well as its ready availability. The objective of this research work is to develop an effective propylated Dioscorea abyssinica starch (PDAS) as a hydrophobic excipient for pharmaceutical applications with a reasonable price. This paper reports on the synthesis, characterization, and in vivo safety evaluation of PDAS. Native Dioscorea abyssinica starch (NDAS) was modified to its propylated form with propionic anhydride and characterized. Crystallinity, morphological structure, thermal behavior, solubility, and safety of PDAS were evaluated using x-ray diffraction, SEM, thermogravimetric, gravimetric, and toxicity studies, respectively. Propionyl content and degree of substitution (DS) of starch increased significantly (p < 0.05) with an increase in reaction time and temperature. Propionyl content and DS of starch increased significantly (p < 0.05) with a decrease in the ratio of starch to pyridine and starch to propionic anhydride in the reaction medium. FTIR spectra of PDAS indicated that hydroxyl groups participated in the propylation reaction. X-ray diffraction results showed that the chemical modification destroyed the crystalline structure of the NDAS. SEM of NDAS showed a rounded shape which became irregular after propylation. Thermogravimetric curves revealed that all the PDAS samples decomposed at higher temperatures than their native counterparts. At higher DS, swelling power and solubility in an aqueous environment significantly (p < 0.05) decreased below that of the native starch. PDAS with high DS, were soluble in organic solvents at room temperature. But PDAS with lower DS didn't dissolve in all types of organic solvents used. PDAS (DS = 2.842) in distilled water did not produce adverse effects in rats. Based on the results obtained, it can be concluded that PDAS can be considered as a generally safe excipient and fulfills the physicochemical properties of a hydrophobic excipient.
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Dioscorea , Animales , Ratas , Almidón , Excipientes , SolventesRESUMEN
OBJECTIVE: To assess the practices and dose uniformity of tablet splitting at selected public hospitals in Northwest Ethiopia. METHODS: A hybrid study method was employed to see the overall practices of tablet splitting. A prospective cross-sectional study was conducted to explore the practices of tablet splitting by administering structured questionnaires to patients and pharmacy professionals. Experimental data on dose and content uniformity of split tablets were obtained from the results of drugs split by study subjects. The content uniformity assay was performed using UV/Vis spectrophotometry. RESULTS: A total of 241 patients and 82 pharmacy professionals participated in the cross-sectional study. The majority of patient participants (51.3%) faced problems while splitting their tablet medications and this had a significant association with the education level of the patients (χ2 = 60.5; p = 0.001). Enteric-coated formulations were dispensed to be split, despite the precaution given by the manufacturers against splitting or crushing these products. Splitting of enteric-coated products accounts for 11% of the total drugs that were dispensed to be taken after a split. The mean of weight variation test for the half tablets does not meet the specifications set in pharmacopoeias when splitting was done by patients. The unscored haloperidol tablets were hard to split and resulted in a significant weight variation of half-tablets than the scored furosemide tablets. Moreover, the weight of 4 out of 20 fragments that were split by patients deviated at least by 15%. CONCLUSIONS: This finding showed that the tablet-splitting practices are poor and do not meet the specifications set by pharmacopoeias. Splitting by patients resulted in significantly higher dose variation and weight loss of fragments than splitting by pharmacists.
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Hospitales Públicos , Humanos , Estudios Transversales , Etiopía , Estudios Prospectivos , ComprimidosRESUMEN
AIM: The present research work was aimed to formulate fast disintegrating tablets (FDTs) of salbutamol sulphate (SBS) using a combination of a superdisintegrant and a subliming agent, optimize the formulation and evaluate the in vitro performance of the developed FDTs. MATERIALS AND METHODS: A formulation of SBS FDT was developed using a combination of superdisintegrant - crospovidone and subliming agent - Ammonium Bicarbonate (AB) in which formulation variables, namely levels of crospovidone and Microcrystalline Cellulose (MCC):Mannitol (MNTL) ratio, were evaluated for their effects on the response variables, disintegration time, hardness, friability and wetting time, of the resulting FDTs. By employing Central Composite Design (CCD) methodology, the FDTs were optimized to achieve optimum levels of the formulation factors. RESULTS: The desired optimum condition was obtained at 7.82% crospovidone and 70% of 1.56:1 MCC: MNTL ratio, while maintaining AB at 5% level for aesthetic reasons. Under the optimized conditions, the disintegration time, hardness, friability, and wetting time were 14.57 ± 0.53 sec, 7.17 ± 0.82 kg/cm2, 0.311% and 13.14 ± 0.69 sec, respectively. The experimentally observed responses were found to be in close agreement with the predicted values for the optimized formulation. Moreover, the validity of the obtained optimal point was confirmed by the low magnitude of percent prediction error (< 5%). CONCLUSION: FDTs of SBS were successfully formulated and optimized using CCD employing a combination of a superdisintegrant and a subliming agent.
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Albuterol , Povidona , Povidona/química , Solubilidad , Sulfatos , Comprimidos/químicaRESUMEN
Decades ago, the United Nations declared that access to essential medicines was a key element of universal human rights. Accordingly, member states have been striving to address this issue through strategic policies and programs. Strengthening local pharmaceutical production has been a pivotal strategy adopted by many developing countries including Ethiopia. The government of Ethiopia identified local pharmaceutical production as a key industrial sector and has been implementing a ten-years strategic plan to improve capabilities and attract investment. Such support is needed because local production could satisfy only 15 to 20% of the national demand, typically from a limited portfolio of medicines in conventional dosage forms. The increasing prevalence of chronic diseases has accentuated the need for a more sustainable supply to reduce reliance on imports and increase access to essential medicines. A full understanding of the structure, constraints and complexities of the Ethiopian pharmaceutical market structure is vital to direct effective policies, target most impactful investments and exploit opportunities for leapfrogging. Hence, the purpose of this review was to assess the trends and challenges in access to essential medicines and local pharmaceutical production in Ethiopia. Literature search through major databases and review of policy documents and performance reports from relevant sector institutions were made to extract information for the review.
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Medicamentos Esenciales , Humanos , EtiopíaRESUMEN
OBJECTIVE: Globally, interest in excellence has grown exponentially, with public and private institutions shifting their attention from meeting targets to achieving excellence. Centres of Excellence (CoEs) are standing at the forefront of healthcare, research and innovations responding to the world's most complex problems. However, their potential is hindered by conceptual ambiguity. We conducted a global synthesis of the evidence to conceptualise CoEs. DESIGN: Scoping review, following Arksey and O'Malley's framework and methodological enhancement by Levac et al and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews. DATA SOURCES: PubMed, Scopus, CINAHL, Google Scholar and the Google engine until 1 January 2021. ELIGIBILITY: Articles that describe CoE as the main theme. RESULTS: The search resulted in 52 161 potential publications, with 78 articles met the eligibility criteria. The 78 articles were from 33 countries, of which 35 were from the USA, 3 each from Nigeria, South Africa, Spain and India, and 2 each from Ethiopia, Canada, Russia, Colombia, Sweden, Greece and Peru. The rest 17 were from various countries. The articles involved six thematic areas-healthcare, education, research, industry, information technology and general concepts on CoE. The analysis documented success stories of using the brand 'CoE'-an inï¬uential brand to stimulate best practices. We identified 12 essential foundations of CoE-specialised expertise; infrastructure; innovation; high-impact research; quality service; accreditation or standards; leadership; organisational structure; strategy; collaboration and partnership; sustainable funding or financial mechanisms; and entrepreneurship. CONCLUSIONS: CoEs have significant scientific, political, economic and social impacts. However, there are inconsistent use and self-designation of the brand without approval by an independent, external process of evaluation and with high ambiguity between 'CoEs' and the ordinary 'institutions' or 'centres'. A comprehensive framework is needed to guide and inspire an institution as a CoE and to help government and funding institutions shape and oversee CoEs.
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Atención a la Salud , Instituciones de Salud , Etiopía , Humanos , Liderazgo , NigeriaRESUMEN
Ranitidine HCl, a selective, competitive histamine H2-receptor antagonist with a short biological half-life, low bioavailability and narrow absorption window, is an ideal candidate for gastro-retentive drug delivery system (GRDDS). Controlled release with an optimum retentive formulation in the upper stomach would be an ideal formulation for this drug. The aim of the present study was therefore to develop, formulate and optimize floating, bioadhesive, and swellable matrix tablets of ranitidine HCl. The matrix tablets were prepared using a combination of hydroxypropyl methylcellulose (HPMC) and sodium carboxymethyl cellulose (NaCMC) as release retarding polymers, sodium bicarbonate (NaHCO3) as gas generating agent and microcrystalline cellulose (MCC) as direct compression diluent. Central composite design (CCD) was used to optimize the formulation and a total of thirteen formulations were prepared. Concentration of HPMC/NaCMC (3:1) (X1) and NaHCO3 (X2) were selected as independent variables; and floating lag time (Y1), bioadhesive strength (Y2), swelling index at 12 h (Y3), cumulative drug release at 1 h (Y4), time to 50% drug release (t50%) (Y5) and cumulative drug release at 12 h (Y6) were taken as the response variables. The optimized batch showed floating lag time of 5.09 sec, bioadhesive strength of 29.69 g, swelling index of 315.04% at 12 h, t50% of 3.86 h and drug release of 24.21% and 93.65% at 1h and 12 h, respectively, with anomalous release mechanism. The results indicate that sustained release matrix tablet of ranitidine HCl with combined floating, bioadhesive and swelling gastro-retentive properties can be considered as a strategy to overcome the low bioavailability and in vivo variation associated with the conventional ranitidine HCl tablet.
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Celulosa/química , Ranitidina/química , Ranitidina/farmacocinética , Bicarbonato de Sodio/química , Preparaciones de Acción Retardada/química , Preparaciones de Acción Retardada/farmacocinética , Liberación de Fármacos , ComprimidosRESUMEN
Ceramides (CERs) play a major role in skin barrier function and direct replacement of depleted skin CERs, due to skin disorder or aging, has beneficial effects in improving skin barrier function and skin hydration. Though, plants are reliable source of CERs, absence of economical and effective method of hydrolysis to convert the dominant plant sphingolipid, glucosylceramides (GlcCERs), into CERs remains a challenge. This study aims at exploring alternative GlcCERs sources and chemical method of hydrolysis into CERs for dermal application. GlcCERs isolated from lupin bean (Lupinus albus), mung bean (Vigna radiate) and naked barley (Hordium vulgare) were identified using ultra high performance liquid chromatography hyphenated with atmospheric pressure chemical ionization - high resolution tandem mass spectrometer (UHPLC/APCI-HRMS/MS) and quantified with validated automated multiple development-high performance thin layer chromatography (AMD-HPTLC) method. Plant GlcCERs were hydrolyzed into CERs with mild acid hydrolysis (0.1 N HCl) after treating them with oxidizing agent, NaIO4, and reducing agent, NaBH4. GlcCERs with 4,8-sphingadienine, 8-sphingenine and 4-hydroxy-8-sphingenine sphingoid bases linked with C14 to C26 α-hydroxylated fatty acids (FAs) were identified. Single GlcCER (m/z 714.5520) was dominant in lupin and mung beans while five major GlcCERs species (m/z 714.5520, m/z 742.5829, m/z 770.6144, m/z 842.6719 and m/z 844.56875) were obtained from naked barley. The GlcCERs contents of the three plants were comparable. However, lupin bean contains predominantly (> 98 %) a single GlcCER (m/z 714.5520). Considering the affordability, GlcCER content and yield, lupin bean would be the preferred alternative commercial source of GlcCERs. CER species bearing 4,8-sphingadienine and 8-sphingenine sphingoid bases attached to C14 to 24 FAs were found after mild acid hydrolysis. CER species with m/z 552.4992 was the main component in the beans while CER with m/z 608.5613 was dominant in the naked barley. However, CERs with 4-hydroxy-8-sphingenine sphingoid base were not detected in UHPLC-HRMS/MS study suggesting that the method works for mainly GlcCERs carrying dihydroxy sphingoid bases. The method is economical and effective which potentiates the commercialization of plant CERs for dermal application.
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Ceramidas , Glucosilceramidas , Cromatografía Líquida de Alta Presión , Espectrometría de Masas , PlantasRESUMEN
There is no ethnobotanical study conducted specifically on medicinal plants traditionally used to treat cancer in Ethiopia. Yet, traditional herbalists in different parts of the country claim that they have been treating cancer-like symptoms using herbal remedies. The objective of this study was to document medicinal plants traditionally used to treat cancer-like symptoms in eleven districts, Ethiopia. Traditional herbalists were interviewed using semistructured questionnaires, and field visits were also carried out to collect claimed plants for identification purpose. Seventy-four traditional herbalists, who claimed that they knew about and/or had used medicinal plants to treat cancer-like symptoms, were selected using the snowball method and interviewed. Herbalists used their intuition and relied on the chronicity, growth of external mass, and spreading of the disease to other parts of the body, as a means to characterize cancer symptoms. Furthermore, in some of the study districts, herbalists reported that they treat patients who had already been diagnosed in modern healthcare institutions prior to seeking help from them. The inventory of medicinal plants is summarized in a synoptic table, which contains the scientific and vernacular names of the plants, their geographical location, the parts of the plants, and the methods used to prepare the remedies. A total of 53 traditionally used anticancer plants, belonging to 30 families, were identified during the survey. The most frequently reported anticancer plants were Acmella caulirhiza Del (Asteraceae), Clematis simensis Fresen. (Ranunculaceae), Croton macrostachyus Del. (Euphorbiaceae), and Dorstenia barnimiana Schweinf. (Moraceae). Organizing traditional healers, documenting their indigenous knowledge, and scientifically validating it for the development of better cancer therapeutic agents constitute an urgent and important task for policymakers and scientists.
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Celluloses were extracted from teff straw (TS), enset fiber (EF), sugarcane bagasse (SB) and coffee hull (CH) agro-industrial byproducts generated in large quantities in Ethiopia. The present study aimed to explore these plant byproducts as alternative sources of cellulose for potential industrial applications, using various eco-friendly chlorine-free treatment conditions to obtain an optimum cellulose extraction condition. The byproducts and the as-extracted celluloses were analyzed for chemical compositions, yield, chemical functionality, crystallinity, thermal stability and morphology. EF yielded the highest cellulose content (60.0%), whereas CH the least (35.5%). FTIR spectra and ESEM morphological studies of the celluloses indicated progressive removal of non-cellulosic constituents. XRD analyses showed EF cellulose had the highest crystallinity index (CrI) (85.56%), crystallite size (5.52â¯nm), and proportion of crystallite interior chains of 200 plane (0.629), exhibiting unique physicochemical properties. The byproducts and the as-extracted celluloses showed Cellulose Iß crystal lattice, while celluloses from EF and SB also displayed (partial) polymorphic transition into Cellulose II. TGA studies revealed enhanced stability of the as-extracted celluloses. On the basis of the physicochemical characteristics of the celluloses, all the byproducts studied could be considered as alternative sources of cellulose for potential value-added industrial applications.