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1.
PLoS One ; 17(11): e0276965, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36441719

RESUMEN

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.


Asunto(s)
Dioscorea , Animales , Ratas , Almidón , Excipientes , Solventes
2.
Ethiop J Health Sci ; 32(5): 1027-1042, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-36262708

RESUMEN

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.


Asunto(s)
Medicamentos Esenciales , Humanos , Etiopía
3.
PLoS One ; 16(6): e0253391, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34170952

RESUMEN

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.


Asunto(s)
Celulosa/química , Ranitidina/química , Ranitidina/farmacocinética , Bicarbonato de Sodio/química , Preparaciones de Acción Retardada/química , Preparaciones de Acción Retardada/farmacocinética , Liberación de Fármacos , Comprimidos
4.
Amino Acids ; 53(7): 1105-1122, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34106335

RESUMEN

Free amino acids (FAAs), the major constituents of the natural moisturizing factor (NMF), are very important for maintaining the moisture balance of human skin and their deficiency results in dry skin conditions. There is a great interest in the identification and use of nature-based sources of these molecules for such cosmeceutical applications. The objective of the present study was, therefore, to investigate the FAA contents of selected Ethiopian plant and fungi species; and select the best sources so as to use them for the stated purpose. About 59 different plant species and oyster mushroom were included in the study and the concentrations of 27 FAAs were analyzed. Each sample was collected, lyophilized, extracted using aqueous solvent, derivatized with Fluorenylmethoxycarbonyl chloride (Fmoc-Cl) prior to solid-phase extraction and quantified using Liquid Chromatography Electrospray Ionization Tandem Mass Spectrometric (LC-ESI-MS/MS) system. All the 27 FAAs were detected in most of the samples. The dominant FAAs that are part of the NMF were found at sufficiently high concentration in the mushroom and some of the plants. This indicates that FAAs that could be included in the preparations for the management of dry skin condition can be obtained from a single natural resource and the use of these resources for the specified purpose have both economic and therapeutic advantage in addition to fulfilling customer needs.


Asunto(s)
Aminoácidos/metabolismo , Cosmecéuticos/metabolismo , Hongos/metabolismo , Plantas/metabolismo , Piel/metabolismo , Aminoácidos/análisis , Cromatografía Liquida , Cosmecéuticos/análisis , Humanos , Espectrometría de Masas en Tándem
5.
J Pharm Biomed Anal ; 192: 113677, 2021 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-33099117

RESUMEN

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.


Asunto(s)
Ceramidas , Glucosilceramidas , Cromatografía Líquida de Alta Presión , Espectrometría de Masas , Plantas
6.
Int J Biol Macromol ; 2020 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-32437811

RESUMEN

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 (5.52 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.

7.
Anal Bioanal Chem ; 410(20): 4775-4785, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29947900

RESUMEN

Ceramides (CERs) are the backbone of the intercellular lipid lamellae of the stratum corneum (SC), the outer layer of the skin. Skin diseases such as atopic dermatitis, psoriasis, and aged skin are characterized by dysfunctional skin barrier and dryness which are associated with reduced levels of CERs. Replenishing the depleted epidermal CERs with exogenous CERs has been shown to have beneficial effects in improving the skin barrier and hydration. The exogenous CERs such as phyto-derived CERs (PhytoCERs) can be delivered deep into the SC using novel topical formulations. This, however, requires investigating the rate and extent of skin permeation of CERs. In this study, an LC/APCI-MS method to detect and quantify PhytoCERs in different layers of the skin has been developed and validated. The method was used to investigate the skin permeation of PhytoCERs using Franz diffusion cells after applying an amphiphilic cream containing PhytoCERs to the surface of ex vivo human skin. As plant-specific CERs are not commercially available, well-characterized CERs isolated from oat (Avena abyssinica) were used as reference standards for the development and validation of the method. The method was linear over the range of 30-1050 ng/mL and sensitive with limit of detection and quantification of 10 and 30 ng/mL, respectively. The method was also selective, accurate, and precise with minimal matrix effect (with mean matrix factor around 100%). Even if more than 85% of oat CERs in the cream remained in the cream after the incubation periods of 30, 100, and 300 min, it was possible to quantify the small quantities of oat CERs distributed across the SC, epidermis, and dermis of the skin indicating the method's sensitivity. Therefore, the method can be used to investigate the skin permeation of oat CERs from the various pharmaceutical and cosmeceutical products without any interference from the skin constituents such as the epidermal lipids. Graphical abstract ᅟ.


Asunto(s)
Ceramidas/farmacocinética , Cromatografía Líquida de Alta Presión/métodos , Espectrometría de Masas/métodos , Absorción Cutánea , Piel/metabolismo , Avena/química , Ceramidas/análisis , Humanos , Límite de Detección , Glycine max/química
8.
Eur J Pharm Biopharm ; 127: 260-269, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29501672

RESUMEN

Deficiency or altered composition of stratum corneum (SC) lipids such as ceramides (CERs), causing skin barrier dysfunction and skin dryness, have been associated with skin diseases such as atopic dermatitis and psoriasis, and ageing. Replenishing the depleted native CERs with exogenous CERs has also been shown to have beneficial effects in restoring the skin barrier. Phyto-derived CERs such as oat CERs were shown to be potential for skin barrier reinforcement. To effect this, however, the oat CERs should overcome the SC barrier and delivered deep into the lipid matrix using the various novel formulations. In an attempt to demonstrate the potential use of oat CERs, lecithin-based microemulsions (MEs) and starch-based nanoparticles (NPs) were formulated and characterized. Besides, ME gel and NP gel were also prepared using Carbopol®980 as a gelling agent. The in vitro release and penetration (using artificial four-layer membrane system) and ex vivo permeation (using excised human skin) of oat CERs from the various formulations were investigated. The results revealed ME enhanced the in vitro release and penetration oat CERs compared to the other formulations. On the other hand, the NPs retarded the release of oat CERs and small quantities of oat CERs incorporated into NP gel penetrated into the deeper layers of the multilayer membranes. The penetration-enhancing effect of ME was also observed in the ex vivo permeation studies where significant quantities of oat CERs were found in the acceptor compartment. Compared to the ME, the ME gel exhibited reduced depth and extent of oat CERs permeation. As compared to NP gel, ME gel enhanced the degree of permeation of oat CERs into the deeper layer of the skin. Generally the gel formulations were effective in concentrating oat CERs in the SC where they are needed to be.


Asunto(s)
Avena/química , Ceramidas/administración & dosificación , Ceramidas/química , Nanopartículas/química , Piel/efectos de los fármacos , Química Farmacéutica/métodos , Portadores de Fármacos/química , Sistemas de Liberación de Medicamentos/métodos , Humanos , Lecitinas/química , Lípidos/química , Permeabilidad/efectos de los fármacos , Absorción Cutánea/efectos de los fármacos , Enfermedades de la Piel/tratamiento farmacológico
9.
J Chromatogr B Analyt Technol Biomed Life Sci ; 1065-1066: 87-95, 2017 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-28950193

RESUMEN

The impaired epidermal barrier and skin dryness in chronic skin conditions such as atopic dermatitis, psoriasis and aged skin are associated with the depletion of ceramides (CERs) in the stratum corneum. Previously, the beneficial effects of phyto-CERs, mainly from wheat and rice, in replenishing the depleted epidermal CERs and restoring the skin barrier have been shown. However, very few efforts have been made to exploit CERs from other plants for dermal applications. In an attempt to explore alternative plant source of CERs, glucosylceramides (GlcCERs) were isolated from the lipid extract of Ethiopian oat grain (Avena abyssinica). The GlcCER species were separated on a reversed phase HPLC and the structure of individual GlcCERs were identified by tandem MS with atmospheric pressure chemical ionization interface. The glycosidic linkage of the GlcCERs was cleaved by acid treatment and the predominant CERs species were isolated using column chromatography and preparative LC-MS. Further structural characterization of the CERs was made by HR/ESI-MS and NMR analyses. All the detected oat-derived GlcCER species consisted of C18 dihydroxy sphingoid bases amide-linked with α-hydroxylated saturated fatty acids (C16-C24). The two predominant GlcCER species consisted of sphingenine (d18:1) amide-linked to hydroxypalmitic acid (h16:0) and hydroxyarachidic acid (h20:0). The molecular formulae of the two major CERs assigned by HR/ESI-MS were identical to the ones identified by LC/APCI-MS/MS. The structural information was also supported by 1H, 13C, 1H COSY NMR and HMBC spectral analyses. The amount of GlcCERs in oat grain, quantified by HPTLC, was found to be 193.5mg/kg. The results indicated the similarity of oat CERs with commercial plant CERs (with comparable GlcCER content) suggesting its potential as source of CERs for oral (as dietary supplements) as well as topical applications.


Asunto(s)
Avena/química , Cromatografía Líquida de Alta Presión/métodos , Glucosilceramidas/análisis , Glucosilceramidas/química , Extractos Vegetales/química , Espectrometría de Masas en Tándem/métodos , Administración Tópica , Fármacos Dermatológicos
10.
J Pharm Biomed Anal ; 141: 241-249, 2017 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-28463779

RESUMEN

Chronic skin conditions such as atopic dermatitis, psoriasis and aged skin are characterized by defective skin barrier and dryness which are associated with reduced levels of skin ceramides (CERs). The beneficial effects of plant-derived CERs for skin hydration and skin barrier recovery have been shown in several studies. Although plenty of glucosylceramide (GlcCER)-based dietary supplements meant for skin barrier improvement have been marketed, there are limited commercial sources of plant GlcCERs. In an attempt to explore alternative GlcCER sources, a reversed phase LC-MS/MS method with atmospheric pressure chemical ionization (APCI) interface was developed for separation and structural identification of GlcCERs isolated from three plants. The GlcCERs were extracted from the seeds of grass pea (Lathyrus sativus L.), Ethiopian mustard (Brassica carinata) and haricot bean (Phaseolus vulgaris) and purified by column chromatography and preparative LC-MS. The individual GlcCER species were further separated and qualitatively analyzed by LC/APCI-MS/MS. The amount of GlcCERs in each plant was quantified by HPTLC. All GlcCER species detected in the three plants consisted of C18 di/trihydroxy sphingoid bases amide linked with hydroxy fatty acids (C14-C24). The trihydroxy SBs were acylated with very long chain FAs (C22-C24). The major GlcCERs derived from grass pea, Ethiopian mustard and haricot bean are composed of sphingenine (d18:1) linked to hydroxypalmitic acid (h16:0), 4-hydroxy-8-sphingenine (t18:1) coupled with hydroxynervonic acid (h24:1) and sphingadienine (d18:2) joined with h16:0, respectively. The GlcCERs contents in haricot bean (161.2mg/kg) and grass pea (130.0mg/kg) were found to be higher compared to Ethiopian mustard (71.8mg/kg). This qualitative and quantitative information suggests that the two plants of the Fabaceae family (haricot bean and grass pea) are potential alternative sources of GlcCERs for their use in products meant for the recovery of skin barrier function. The LC/APCI-MS/MS method described here has proven to be reliable for the screening of other potential plants containing GlcCERs.


Asunto(s)
Glucosilceramidas/análisis , Presión Atmosférica , Cromatografía Liquida , Plantas , Esfingosina/análogos & derivados , Espectrometría de Masas en Tándem
11.
Skin Pharmacol Physiol ; 30(3): 115-138, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28407621

RESUMEN

The outer most layer of the skin, the stratum corneum, consists of corneocytes which are coated by a cornified envelope and embedded in a lipid matrix of ordered lamellar structure. It is responsible for the skin barrier function. Ceramides (CERs) are the backbone of the intercellular lipid membranes. Skin diseases such as atopic dermatitis and psoriasis and aged skin are characterized by dysfunctional skin barrier and dryness which are associated with reduced levels of CERs. Previously, the effectiveness of supplementation of synthetic and animal-based CERs in replenishing the depleted natural skin CERs and restoring the skin barrier function have been investigated. Recently, however, the barrier function improving effect of plant-derived CERs has attracted much attention. Phyto-derived CERs (phytoCERs) are preferable due to their assumed higher safety as they are mostly isolated from dietary sources. The beneficial effects of phytoCER-based oral dietary supplements for skin hydration and skin barrier reinforcement have been indicated in several studies involving animal models as well as human subjects. Ingestible dietary supplements containing phytoCERs are also widely available on the market. Nonetheless, little effort has been made to investigate the potential cosmetic applications of topically administered phytoCERs. Therefore, summarizing the foregoing investigations and identifying the gap in the scientific data on plant-derived CERs intended for skin-health benefits are of paramount importance. In this review, an attempt is made to synthesize the information available in the literature regarding the effects of phytoCER-based oral dietary supplements on skin hydration and barrier function with the underlying mechanisms.


Asunto(s)
Ceramidas/farmacología , Epidermis/efectos de los fármacos , Fitoquímicos/farmacología , Administración Oral , Animales , Ceramidas/química , Ceramidas/metabolismo , Ceramidas/uso terapéutico , Dermatitis Atópica/tratamiento farmacológico , Dermatitis Atópica/metabolismo , Epidermis/metabolismo , Humanos , Queratinocitos/metabolismo , Magnoliopsida/química , Permeabilidad/efectos de los fármacos , Fitoquímicos/química , Fitoquímicos/uso terapéutico , Psoriasis/tratamiento farmacológico , Psoriasis/metabolismo
12.
Skin Pharmacol Physiol ; 28(1): 42-55, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25196193

RESUMEN

The skin is the largest organ of the body, whose main function is to protect the body against the loss of physiologically important components as well as harmful environmental insults. From the inside to the outside, the skin comprises three major structural layers: the hypodermis, the dermis and the epidermis. The epidermis contains four different sublayers, the stratum corneum (SC), stratum granulosum, stratum spinosum and stratum basale, where the barrier function of the skin mainly lies in the outermost layer of the epidermis, the SC. The SC contains corneocytes that are embedded in a lipid matrix existing in the form of lipid bilayers. The lipid bilayers are formed mainly from ceramides, free fatty acids and cholesterol, constitute the only continuous pathway across the SC and are responsible for the barrier function of the skin. However, the depletion or disturbance of SC lipids in the SC leads to a perturbation of the barrier function of the skin, and, conversely, several skin diseases such as psoriasis and atopic dermatitis are associated with the depletion of these SC lipids. Therefore, it is of paramount importance to understand the interrelationship between the depletion of SC lipids and skin diseases as well as factors that affect the composition and organization of SC lipids in order to assess the potential benefit of a direct replacement of the missing SC lipids as a means of treating affected, aged or diseased skin.


Asunto(s)
Epidermis/metabolismo , Metabolismo de los Lípidos , Enfermedades de la Piel/metabolismo , Animales , Humanos , Enfermedades de la Piel/terapia
13.
Trials ; 15: 493, 2014 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-25526797

RESUMEN

Low income countries like Ethiopia are underrepresented in clinical research. As a major public commitment to clinical research, Ethiopia celebrated the International Clinical Trial Day (ICTD) for the first time on 20 May 2014 under the auspices of Addis Ababa University. The motto for the day was 'Clinical Trials for Excellence in Patient Care'. The celebration offered an opportunity to inform academic staff, researchers, students and the leadership about clinical trials being conducted and to discuss the future of clinical trials in the country. Although clear challenges to the conduct of trials abound, clinical trials registered from Ethiopia in trial registration databases is increasing. Cross-country collaborations, international funding support, motivation of academic staff to conduct clinical trials and the commitment and engagement of the leadership in research are all improving. The overall impact of clinical trials is also encouraging. For example, some of the trials conducted in Ethiopia have informed treatment guidelines. However, administrative capacity, research infrastructure as well as financial support remain weak. There is a need for enhanced university-industry linkage and translation of research findings into locally relevant evidence. Ethiopia, as well as the whole of Africa, has an unparalleled opportunity to lead the way in clinical trials, given its prospect of development and the need to have locally relevant evidence for its growing population. In this commentary we reflect on the celebration of ICTD, the status and opportunities for conducting clinical trials and the way forward for facilitating clinical trials in Ethiopia and Africa.


Asunto(s)
Ensayos Clínicos como Asunto/métodos , Países en Desarrollo , Proyectos de Investigación , África , Actitud del Personal de Salud , Ensayos Clínicos como Asunto/economía , Ensayos Clínicos como Asunto/ética , Ensayos Clínicos como Asunto/normas , Conducta Cooperativa , Países en Desarrollo/economía , Etiopía , Humanos , Comunicación Interdisciplinaria , Cooperación Internacional , Motivación , Selección de Paciente , Guías de Práctica Clínica como Asunto , Proyectos de Investigación/normas , Investigadores/psicología , Apoyo a la Investigación como Asunto
14.
Pak J Pharm Sci ; 26(1): 23-9, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23261724

RESUMEN

Some excipients are currently available for the formulation of pharmaceutical suspensions. The purpose of this study is to develop cheap and effective natural excipient that can be used as an effective alternative for the formulation of pharmaceutical suspensions. The suspending properties of Opuntia ficus-indica and Opuntia stricta mucilages (family Cactaceae) were evaluated comparatively with that of NaCMC at concentration range of 2-6% (w/v) in Paracetamol suspension. Sedimentation volume (%) (with and without electrolyte), rheology, redispersibility, and dissolution rate of the suspensions were employed as evaluation parameters. The values obtained were used as basis for comparison of the suspending agents. The apparent viscosities of the suspensions in all the suspending agents concentration levels and applied shear rates were in the order of NaCMC>OS>OFI with non-Newtonian flow and accordingly the flow rates of the suspensions were in the order of OFI > OS > NaCMC. The sedimentation volumes (%) of the suspensions in all the suspending agent concentration levels were higher for OS followed by OFI and then NaCMC. The high sedimentation volumes (%) of suspensions, in turn, were accompanied by ease of redispersibility of that order. The effect of electrolyte on sedimentation volume (%) had dual effect. It was only the suspensions that had NaCMC that showed increase in sedimentation volume (%) in all molar NaCl concentration. However, in suspensions that had mucilages of OS and OFI, an initial increase in sediment volumes (%) were accompanied by decrease after 1x10(-3)M and 1x10(-2)M of NaCl, respectively. Dissolution of the suspensions which had mucilages attained the acceptable ranges (> 80% drug release in 30 min) in 5 min. Similarly, except A6 formulations A2, A3, A4 and A5 have attained the limit but the release was not as quick as the previous formulations. Hence, it can be concluded that mucilages of Opuntia spp. (Opuntia ficus-indica and Opuntia stricta) can be used as alternatives to NaCMC as suspending agent in suspension formulations.


Asunto(s)
Acetaminofén/química , Analgésicos no Narcóticos/química , Excipientes/química , Opuntia , Mucílago de Planta/química , Carboximetilcelulosa de Sodio/química , Química Farmacéutica , Excipientes/aislamiento & purificación , Floculación , Cinética , Modelos Químicos , Opuntia/química , Soluciones Farmacéuticas , Mucílago de Planta/aislamiento & purificación , Reología , Cloruro de Sodio/química , Solubilidad , Tecnología Farmacéutica/métodos , Viscosidad
15.
Phytother Res ; 24(1): 60-9, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19441008

RESUMEN

Despite advances in the understanding of the medicinal properties of many herbs, the consumer today is confronted with the lack of or misinformation concerning the safety of these herbs that rivals the heyday of the patent medicine era. In the present study, Dodonaea viscosa (Sapindaceae), a medicinal plant commonly used for skin diseases in Ethiopia was subjected to a systematic dermatotoxicity study. To this effect, the dermatotoxicity of an 80% methanol extract of the leaf was investigated in animals following standard procedures for irritation, sensitization, acute toxicity and repeated toxicity tests. The skin irritation test in rabbits showed the extract to be a slight or negligibly slight irritant, with a primary irritation index of 0.45. A sensitization test in mice by the mouse ear swelling test method revealed the extract to be a non-sensitizer in the dose range 12-30 mg/mL. The percent responder was zero. The acute and repeated dermal toxicity tests on rats did not show any overt sign of toxicity. The findings of this study collectively indicate that dermal application of D. viscosa is not associated with any toxicologically relevant effects and the data could provide satisfactory preclinical evidence of safety to launch a clinical trial on a standardized formulation of the plant extracts.


Asunto(s)
Extractos Vegetales/toxicidad , Sapindaceae/química , Piel/efectos de los fármacos , Administración Cutánea , Animales , Femenino , Masculino , Medicinas Tradicionales Africanas , Ratones , Hojas de la Planta/toxicidad , Plantas Medicinales/toxicidad , Conejos , Ratas , Pruebas de Toxicidad
16.
Afr J AIDS Res ; 9(1): 31-40, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25860411

RESUMEN

The Amharic version of the Short Form-36 Health Survey (SF-36) was used to measure quality of life among patients on highly active antiretroviral therapy (HAART) at selected governmental hospitals in central and southern Ethiopia. The study was cross-sectional and used SF-36-specific software for automatic scoring of the form's scales and dimensions. Pearson bivariate correlations showed moderate correlation between the SF-36 scales, ranging from 0.2673 between 'general health' and 'vitality,' to 0.8583 between 'role physical' and 'role emotional.' Cronbach's-αwas >0.70 for six out of eight multi-item scales, with values ranging from 0.6500 to 0.8860 for all scales, thus indicating good internal reliability of the Amharic version of the SF-36. The independent variables shown to positively affect mean scores were: duration of treatment, CD4 cell count, and adherence to doses of antiretrovirals. Participants treated for >12 months had higher mean scores for all domains than those who had been treated for ≤12 months. Likewise, those with a CD4 cell count >200 cells/mm(3) had better mean scores for all scales except 'social functioning' and 'mental health' than those with counts ≤200. Participants adhering to treatment (in the last 15 days, according to self-report) had better mean scores for all scales except 'role physical,' 'bodily pain' and 'vitality' in comparison to those who were not adherent. The findings suggest that the Amharic version of the SF-36 is a valid and reliable health survey instrument for use in Ethiopia to assess the quality of life of people living with HIV/AIDS on HAART.

17.
Pharmacoepidemiol Drug Saf ; 18(11): 1007-15, 2009 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19650153

RESUMEN

OBJECTIVE: To determine the adherence rate and its determinants among people living with HIV/AIDS on highly active antiretroviral therapy (HAART) in selected governmental hospitals from central and south Ethiopia. METHODOLOGY: A cross-sectional study involving both qualitative and quantitative methods was conducted between August and October 2007 in Yirgalem, Hawassa, and Shashemene Hospitals. Quantitative data collection techniques include patient self-report and unannounced pill count and the qualitative methods employed were focus group discussions (FGDs), semi-structured interviews, and observations of health facilities. RESULTS: Whereas females accounted for 56.4% (238), male participants were 43.6% (184) of the total participants. Adherence rate was 93.1% using 15-days self-report, but the rate came down to 88.1% when calculated using the unannounced pill count method (n = 90). Multivariate analysis revealed that being unmarried (OR = 0.119, CI = 0.016-0.901, p = 0.039), unemployment (OR = 0.011, CI = 0.000-0.288, p = 0.007); failure to disclose HIV status (OR = 0.433, CI = 0.198-0.949, p = 0.037); lack of support from family (OR = 0.393, CI = 0.163-0.947, p = 0.037); or others (OR = 0.332, CI = 0.144-0.845, p = 0.043); alcohol drinking (OR = 0.210, CI = 0.071-0.617, p = 0.003); treatment regimen, stavudine(40)-lamuvidine-nevirapine (OR = 0.174, CI = 0.033-0.923, p = 0.040), azathymidine-lamuvidine-nevirapine (OR = 0.172, CI = 0.034-0.867, p = 0.033) and dosing three times daily (OR = 0.073, CI = 0.018-0.290, p = 0.000) regimens were found to be associated with non-adherence. Moreover, time since diagnosis was associated with adherence, as those tested HIV-positive >or= 6 months prior to date of interview (OR = 4.064, CI = 1.23-19.316, p = 0.047) had better adherence rate. CONCLUSION: The adherence rate obtained in this study was higher than the rates seen in developed countries despite the fact that many of the participants live in very poor conditions.


Asunto(s)
Fármacos Anti-VIH/uso terapéutico , Países en Desarrollo , Infecciones por VIH/tratamiento farmacológico , Cumplimiento de la Medicación/estadística & datos numéricos , Adulto , Fármacos Anti-VIH/administración & dosificación , Terapia Antirretroviral Altamente Activa , Estudios Transversales , Países en Desarrollo/estadística & datos numéricos , Esquema de Medicación , Etiopía , Femenino , Infecciones por VIH/epidemiología , Hospitales Municipales , Humanos , Masculino , Encuestas y Cuestionarios
18.
J Ethnobiol Ethnomed ; 5: 14, 2009 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-19409096

RESUMEN

Traditional medicine (TM) has been a major source of health care in Ethiopia as in most developing countries around the world. This survey examined the extent and factors determining the use of TM and medicinal plants by Berta community. One thousand and two hundred households (HHs) and fourteen traditional healers were interviewed using semi-structured questionnaires and six focused group discussions (FGDs) were conducted. The prevalence of the use of TM in the two weeks recall period was 4.6%. The HH economic status was found to have a significant effect while the educational level and age of the patients have no effect either on the care seeking behavior or choice of care. Taking no action about a given health problem and using TM are common in females with low-income HHs. Forty plant species belonging to 23 families were reported, each with local names, methods of preparation and parts used. This study indicates that although the proportion of the population that uses TM may be small it is still an important component of the public health care in the study community as complementary and alternative medicine.


Asunto(s)
Etnobotánica , Medicina Tradicional , Fitoterapia , Plantas Medicinales , Adulto , Niño , Etiopía , Femenino , Humanos , Masculino , Fitoterapia/estadística & datos numéricos , Factores Socioeconómicos
19.
AAPS PharmSciTech ; 9(1): 31-8, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18446458

RESUMEN

The purpose of this research was to improve the hygroscopicity and poor flow properties of the crude dry extract of the seeds of Glinus lotoides and improve the disintegration time of the core-tablets for enteric coated formulation thereof. The liquid crude extract of the plant was adsorbed on granulated colloidal silicon dioxide (Aeroperl 300 Pharma) at 30% w/w and the dry extract preparation (DEP) was dry-granulated with roller-compaction using Micro-Pactor. Hygroscopicity, flow property and disintegration time were improved significantly due to the adsorption and granulation processes. Moreover, the DEP does not become mucilaginous even at higher relative humidity levels (above 65%). Oblong tablets (20 x 8.25 mm) containing 947 mg of the granulated DEP (equivalent to the traditional dose), 363 mg of Avicel PH101 and 90 mg of Ac-di-Sol as disintegrant were formulated using an instrumented eccentric tablet machine at 20 kN. The tablets showed a crushing strength of 195 N, a friability of 0.4% and disintegrated within 9 min. The tablets were then enteric coated using polymethacrylate co-polymers (Eudragit L 100-55 and Kollicoat MAE 100P). The coated tablets resisted disintegration or softening in simulated gastric fluid for a minimum of 2 h and disintegrated within 15 min in intestine simulated fluid at pH 6.8. In addition to controlling the release of the active agents, the enteric coating improved the strength and decreased friability of the core-tablets.


Asunto(s)
Portadores de Fármacos/química , Composición de Medicamentos/métodos , Molluginaceae/química , Extractos Vegetales/química , Semillas/química , Dióxido de Silicio/química , Extractos Vegetales/administración & dosificación , Estrés Mecánico , Comprimidos Recubiertos
20.
J Ethnopharmacol ; 117(2): 236-48, 2008 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-18339496

RESUMEN

Plant-based therapeutic preparations are cyclically returning to complement dermatologic therapy, however, data on the toxicity profile of such plants are lacking. In the present study, Plumbago zeylanica, a medicinal plant commonly used in Ethiopia for skin diseases was subjected to a systematic dermatotoxicity study. To this effect, the dermatotoxicity of 80% methanol extract of the root part of Plumbago zeylanica was investigated in animals following standard procedures for irritation, sensitization, acute toxicity and repeated toxicity tests. Extraction of plant material with 80% methanol resulted in 9.45% of crude extract of Plumbago zeylanica. The skin irritation test on rabbits showed Plumbago zeylanica extract to be a moderate irritant, with a primary irritation index of 2.00. Sensitization test on mice by the Mouse Ear Swelling Test method revealed the extract to be non-sensitizer in a dose range of 4-10mg/ml and the percent responder was zero. Acute dermal toxicity test on rats did not produce any overt signs of toxicity, except that there was a weight gain difference between the test and control groups of female rats. This was not, however, supported by other parameters, like the absolute and relative organ weights. Repeated dose toxicity test was associated with increased relative testis weight (P<0.05) as well as higher values for Blood urea nitrogen and K+ (P<0.05) in both sexes with the highest dose (1000 mg/kg) group, although histopathological analyses failed to lend support to these observations. Taken together, the dermatotoxicity test results from this study suggest that Plumbago zeylanica toxic effects might be limited to effects like moderate irritation.


Asunto(s)
Medicinas Tradicionales Africanas , Extractos Vegetales/toxicidad , Plumbaginaceae/química , Administración Tópica , Animales , Recuento de Células Sanguíneas , Análisis Químico de la Sangre , Dermatitis por Contacto/patología , Edema/inducido químicamente , Edema/patología , Eritema/patología , Etiopía , Femenino , Irritantes/toxicidad , Masculino , Ratones , Tamaño de los Órganos/efectos de los fármacos , Extractos Vegetales/administración & dosificación , Conejos , Ratas , Solventes
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