PHYSICOCHEMICAL CHARACTERIZATION OF STARCH ISOLATED FROM ETHIOPIAN POTATO (PLECTRANTHUS EDULIS)

Starch from the tubers of Ethiopian potato (Plectranthus edulis) (Fam. Lamiaceae) has been isolated and examined for its chemical composition, amylose content and physicochemical properties. The starch yield was about 80.4% on dry weight basis. The proximate composition of the starch on dry weight basis was found to be 0.14% ash, 0.21% lipid, 0.43% protein, and 99.2% starch. The amylose content was 30.6%. Its true density and moisture content values were 1.47 g/mL and 11.2%, respectively. Scanning electron microscopy (SEM) of the starch granules showed characteristic morphology that was by and large oblong (elliptical) with some oval-shaped granules. The starch has normal granule size distribution with a mean particle size of 36.2 µm. The DSC thermograms of the starch obtained from starch-water mixtures (1:1), exhibited gelatinization onset temp. (To) of 69.2 oC, peak temp. (Tp) of 74.3 oC and endset temp. (Te) of 83.3 oC. X-ray diffraction pattern of the starch was typical B-type with a distinctive maximum peak at 17.5o 2θ.The starch possesses higher swelling power and moisture sorption pattern but lower solubility values than those of potato starch at all temperatures studied. Considering the high yield and some similar physicochemical properties to those of potato starch, P. edulis (Ethiopian potato) can be explored as an alternative source of starch for various applications

Trends and Challenges in Access to Essential Medicines in Ethiopia and the Contributions of Local Pharmaceutical Production

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. &nbsp

PREPARATION AND EVALUATION OF CARBOXYMETHYL ENSET AND CASSAVA STARCHES AS PHARMACEUTICAL GELLING AGENTS

Starch is usually modified either chemically, physically or enzymatically to augment its convenience for industrial use. In the current study, starches from Enset and cassava plants were carboxymethylated, and factors which affect the carboxymethylation process and degree of substitution (DS) were studied. The application of the carboxymethyl starches as alternative pharmaceutical gelling agents for topical delivery of drugs was also investigated. Accordingly, nine different topical gel formulations of ibuprofen were prepared. All formulations were evaluated with respect to cosmetic qualities, pH, drug content, viscosity, spreadability, extrudability, in vitro drug release, anti-inflammatory activity and stability. The results showed that carboxymethylation was significantly affected by the starch source, reaction medium, temperature and time. All ibuprofen gel formulations showed homogeneous appearance, smooth texture and pleasant odor. The pH values of the formulations ranged from 6.80 to 7.22. Ibuprofen content ranged between 98.76 and 100.20% ensuring the uniformity of the drug content. The cumulative percent ibuprofen released over 12 h across cellulose membrane ranged from 43.8% cm-2 to 84.5% cm-2. Spreadability, extrudability, the cumulative drug release and diffusion coefficient of ibuprofen were influenced not only by the rheological properties of the formulations but also by the nature of the modified starches. Physicochemically stable ibuprofen gels were obtained with potent anti-inflammatory activities.   Keywords: Enset starch, cassava starch, carboxymethylation, degree of substitution, ibuprofen gel, in vitro drug release, anti-inflammatory activity, stability stud

PHYSICOCHEMICAL CHARACTERIZATION OF ACID MODIFIED DIOSCOREA STARCH AND ITS EVALUATION AS DIRECTLY COMPRESSIBLE EXCIPIENT IN TABLET FORMULATION

D. abyssinica was partially hydrolyzed in 6% HCl solution at room temperature for different lengths of time, (2, 4, 8, 16, and 32 days), dried using oven- and spray- drying techniques and subsequently investigated as directly compressible excipient in paracetamol tablet formulations. Native dioscorea starch (NDS) and oven dried acid modified dioscorea starch (AMDS) exhibited poor flow characteristics, whereas spray dried AMDS was found to be free flowing powder with 21.37 ± 1.39° angle of repose and 13.24 ± 0.76 g/sec flow rate. Both swelling power and percent solubility of the starches were found to increase with increase in temperature; AMDS showed higher percent solubility of 68.53%. Lubricant sensitivity and dilution potential of spray dried NDS and spray dried AMDS were investigated by incorporating magnesium stearate and paracetamol, respectively. In tablet formulations, spray dried AMDS and Starch 1500® tablets were produced with acceptable tablet characteristics up to 1% and 0.5% magnesium stearate concentrations, respectively. The spray dried AMDS was able to accommodate up to 40% paracetamol with acceptable criteria.  Thus, it can be concluded that AMDS can be used as an alternative directly compressible excipient in tablet formulations. Keywords:  Dioscorea starch, acid modification, spray drying, directly compressible excipient

Review of ethnobotanical and ethnopharmacological evidences of some Ethiopian medicinal plants traditionally used for the treatment of cancer

Background: Ethiopia is endowed with enormous diversity of plants. However, the majority of these plants have not been scientifically investigated. Traditional knowledge on the use of plants as medicinal agents has been transferred from generation to generation, as guarded secrets, through the word of mouth, and scientific studies on these herbs have not been properly compiled.Objectives: The main objective of this study was to review published ethnobotanical and ethnopharmacological evidences of Ethiopian medicinal plants with anticancer potentials.Material and methods: A total of 92 articles have been reviewed. They were obtained from search engines such as PubMed, Science Direct and Google Scholar. The following keywords were used to search for the literature inside the databases: plant extract, anticancer, Ethiopia, antioxidant compounds, cytotoxic compounds and in vivo toxicity.Results: The current literature review revealed that about 136 anticancer plants belonging to 57 families have been identified in Ethiopia. Among these, 98 plant species were reported for their traditional use to treat different types of symptomatic cancers. However, only 29 species were scientifically studied for their in vitro cytotoxic or free radical scavenging activities. Plant parts commonly used for preparation of anticancer remedies were leaves (41.4%) and roots (32.8%). Among the reported plant species, whilst the crude extracts of Artemisia annua, Acokanthera schimperi and Catha edulis were found to be potent cytotoxic agents (IC50<15 g/ml), the total extracts of Cassia arereh, Rubus steudneri and Thymus schimperi showed strong radical scavenging activity (IC50 <15 g/ml). Chronic administration of Syzygium guineense hydroalcoholic leaf extract, on the other hand, induced pathological changes in liver and kidney of mice.Conclusions: Although several Ethiopian plants traditionally used for the treatment of cancer were shown to possess cytotoxic and free radical scavenging activities, in most cases compounds responsible for such activities have not been identified. Therefore, activity-guided detailed phytochemical studies coupled with evaluation of the safety particularly on those plant extracts that demonstrated potent activities should be carried out as this may lead to the discovery of safe and cost effective anticancer agents. [Ethiop. J. Health Dev. 2017;31 (3):161-187]Keywords: Ethiopian medicinal plants, Antioxidant, Anticancer, Ethnopharmacology, Traditional us

ASSESSMENT OF GMP COMPLIANCE IN WATER TREATMENT SYSTEMS OF PHARMACEUTICAL INDUSTRIES IN ETHIOPIA

Water is widely used as a raw material, ingredient, and solvent in the processing, formulation, and manufacture of pharmaceutical products, and assessing its quality is of paramount importance. However, to the best of the authors’ knowledge, there hasn’t been any baseline assessment made with regard to the implementation status of Good Manufacturing Practices (GMP) principles in water treatment systems of pharmaceutical industries in Ethiopia. Hence, to assess the level of compliance to GMP in water treatment systems of pharmaceutical industries in Ethiopia, a national survey was conducted in all pharmaceutical industries of the country. Data were collected by employing quantitative and qualitative methods. Self-administered questionnaires were distributed to nine pharmaceutical industries and the response rate was 8 (88.5%). According to the results, none of the industries had an influent and effluent total organic carbon monitoring system. Among the available storage tanks for purified water and water for injection, 7 (87.5%) of them were of a sanitary material. However, in 4 (50%) industries pipes were not made of sanitary material, purified water was not kept circulating at 70-80 oC and there were dead legs in the water lines. The validation results were investigated and corrective action was taken only in 1 (12.5%) of the industries. The compliance of the water treatment systems of most of the industries to WHO GMP principles was found to be below the standard in many aspects. Therefore, it is recommended that the industries should exert maximum efforts to comply with GMP principles.   Keywords: Good manufacturing practices, water treatment system, pharmaceutical industry, Ethiopia, pharmaceutical wate

Conceptualising centres of excellence: a scoping review of global evidence

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 influential 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

Formulation and evaluation of sustained release paracetamol peroral matrix tablets: optimisation and in vitro evaluation

An optimised formulation of sustained release paracetamol peroral matrix tablets for a three-times-daily use was prepared with hydroxypropylmethylcellulose (HPMC). The levels of HPMC 4,000, polyethylene glycol (PEG) 6,000 and lactose were varied according to a 2 level 3-factor full factorial experimental design using the release rate of the drug from the matrices as the response variable. From the dissolution data of the eight tablet formulations that resulted from the experimental design, a polynomial regression equation was generated from which an optimum formulation was obtained. Three different batches of granules of the \'optimum formulation\' were compressed into tablets at a compression force of 15 kN with an instrumented EK-0 Korsch eccentric single punch tablet machine. Evaluation of tablet weight variation, crushing strength and friability demonstrated acceptable results. In vitro dissolution tests also revealed sustained release of the drug for an 8-hour period at the end of which almost complete release was achieved (96.22 ± 0.72%, 97.69 ± 0.20% and 98.94 ± 1.17%, respectively, for the three batches). Keywords: sustained release, paracetamol matrix tablets, hydroxypropylmethylcellulose, in vitro dissolution tests, optimization Ethiopian Pharmaceutical Journal, vol. 22 (2004): 27-3

Evaluation of Opuntia stricta mucilage as sustained release excipient in diclofenac sodium matrix tablet formulations

Over the last few decades, plant derived polymers have received increasing attention due to their diverse pharmaceutical applications including modified and controlled drug delivery. Among these natural polymers, mucilages and gums are versatile excipients for pharmaceutical formulation. The main objective of the present study was to evaluate cactus (Opuntia stricta) mucilage as a matrix forming polymer for sustained release tablet formulations using diclofenac sodium as a model drug. The mucilage from cactus cladode was extracted using distilled water as extracting solvent and ethanol as mucilage precipitant. The mucilage powder was characterized for its physical properties. A 1% w/v solution of the mucilage in water gave a pH of 6.40 ensuring low irritability potential when used in uncoated tablets. Evaluation of the powder flow profile demonstrated fair flow showing the need for incorporating other compressible excipients or using granulation to enhance the flow pattern. The solubility and swelling power of the O. stricta were generally low at low temperature (20 ºC), but increased significantly at higher temperature (85 ºC) (p < 0.05). The percentage moisture sorption ranged from 7.61% at 15% to 79.9% at 100% relative humidity (RH). The granules prepared with water as granulating solvent showed excellent flow property. The crushing strength of wet granulated formulations was higher than directly compressed formulations. The in vitro dissolution study demonstrated that both directly compressed and wet granulated formulations of O. stricta mucilage effectively sustained diclofenac release for over 12 h even at a lower concentration of 10%. However, granulation showed a better matrix performance for sustaining the drug release. All the formulations showed good linearity with respect to Korsmeyer-Peppas equation with 0.45 ≤ n ≤ 0.89 indicating that, non Fickian diffusion was the predominant mechanism of drug release from these formulations. So, O. stricta mucilage can be used as alternative pharmaceutical excipient in the formulation and manufacture of sustained release matrix tablets.Keywords: Opuntia stricta mucilage, direct compression, in vitro drug release, wet granulation, matrix tablet

Preparation and evaluation of dual modified Godare ( Colocasia esculenta) starch as a sustained release excipient in tablet formulations

Starch obtained from Colocasia esculenta, Araceae (locally known as godare) has been pregelatinized, cross-linked and evaluated as a sustained release excipient and hydrophilic matrix former in tablet formulations. The pregelatinized starch (PGS) was cross-linked in a microwave oven at three different powers (90, 220 and 350 W) and reaction times ranging from 1 to 6 min, using sodium hexametaphosphate (SHMP) as cross-linking agent. Theophylline tablets containing 30, 40, and 50% and the modified starches were compressed at a constant compression force. Dissolution profiles of theophylline were determined in 0.1 N HCl for the first 2 h and then in phosphate buffer pH 6.8 for the remaining 10 h. Degree of cross-linking (DC) increased with increasing reaction power and time. The resulting modified starches were found to be freely flowing, moisture and acid resistant. Two of the nine theophylline tablet formulations sustained the release over the study period of 12 h releasing about 90% of the drug. The in vitro drug release showed best fit to Higuchi and Hixson-Crowell models depending on the polymer-drug ratio and the type of matrix formers. The dual modified starch in a concentration ranging from 40 to 50% exhibited the attributes of sustained release matrix-forming polymer in the tablet formulations studied. Keywords: godare starch, dual modification, microwave, sustained release, hydrophilic matri