In this study, xanthan gum-facilitated ethyl cellulose microsponges were prepared by the double emulsification technique and subsequently dispersed in a carbopol gel base for controlled delivery of ...diclofenac sodium to the skin. Scanning electron microscopy revealed the porous, spherical nature of the microsponges. Increase in the drug/polymer ratio (0.4:1, 0.6:1, 0.8:1, m/m) increased their yield (79.1-88.5 %), drug entrapment efficiency (50.0-64.1 %), and mean particle diameter (181-255 μm). Compared to the microsponges with high drug/polymer ratio (0.8:1, m/m), the flux of entrapped drug through excised rat skin decreased by 19.9 % and 17.0 %, respectively, for the microsponges prepared at low and intermediate drug/polymer ratios. When an equivalent amount of pure drug (not entrapped into microsponges) was dispersed into the gel base and the flux was compared, the microsponges (drug/polymer ratio 0.8:1, m/m) were found to reduce the flux by 33.3 %. Whether the drug was dispersed either in un-entrapped or entrapped form into the gel base, the drug permeation through rat skin followed Higuchi's diffusion kinetic model. The microsponges prepared at the lowest drug/polymer ratio exhibited a comparatively slower drug permeation profile and were hence considered most suitable for controlled drug delivery application. FTIR spectroscopy and DSC analyses indicated the chemically stable, amorphous nature of the drug in these microsponges. The gel containing these optimized microsponges was comparable to that of a commercial gel formulation and did not show serious dermal reactions. Hence, the microsponge system obtained at the lowest drug/polymer ratio could be useful for controlled release of diclofenac sodium to the skin.
U radu su opisani mikrospužvasti sustavi s etilcelulozom i ksantan gumom pripravljeni metodom dvostruke emulzifikacije i dispergirani u podlogu s karbopol gelom za 0kontrolirano oslobađanje diklofenak natrija na kožu. Elektronska pretražna mikroskopija potvrdila je poroznu, sferičnu strukturu mikrospužvastih sustava. Povećanjem omjera lijeka i polimera (0,4:1, 0,6:1, 0,8:1, m/m) povećalo se iskorištenje (79,1-88,5 %), količina uklopljenog lijeka (50,0-64,1 %) i srednji promjer čestica (181-255 μ/m). Prolaz uklopljenog lijeka kroz izrezane komade kože štakora smanjio se za 19,9 %, odnosno 17,0 %, kada se omjer lijeka i polimera smanjio s visokog (0,8:1, m/m) na niski i srednji. Oslobađanje iz mikrospužvastih struktura s omjerom lijeka i polimera 0,8:1 (m/m) smanjeno je za 33,3 % u odnosu na oslobađanje ekvivalentne količina lijeka koji nije uklopljen već samo dispergiran u geliranu podlogu. Ako je lijek bio dispergiran kao neuklopljen ili kao uklopljen u geliranu podlogu, permeacija lijeka kroz kožu štakora slijedila je Higuchijev difuzijski kinetički model. Mikrospužvaste strukture pripravljene uz najniži omjer lijeka i polimera pokazale su sporiji permeacijski profil pa ih smatramo najpovoljnijima za kontrolirano oslobađanje lijeka. FTIR spektroskopija i DSC analiza pokazale su da je lijek u mikrospružvastim sustavima stabilan i amorfan. Gel s optimiranim mikrospužvastim sustavom sličan je komercijalnom gelu i ne pokazuje ozbiljne kožne reakcije. Sustav pripravljen s najnižim omjerom lijeka i polimera mogao bi biti pogodan za kontrolirano oslobađanje diklofenak natrija na kožu.
This article addresses questions of solidarity in South African literature before and after the confluent endings of apartheid and the Cold War. Examining works by J. M. Coetzee, Nadine Gordimer and ...Alex La Guma, it highlights how solidarity as a theme has emerged in different forms and narrative settings, often tied to related considerations of utopia and dystopia. Alex La Guma's travel memoir, A Soviet Journey (1978), is foregrounded in particular as a literary work examining this theme as well as symbolizing it through the Soviet Union's support for the anti-apartheid struggle. The article concludes with a consideration of decolonial thought in Latin American studies as a contemporary set of conversations providing a potential intercontinental solidarity of the future.
This contribution suggests a parallel analysis of the debut works of two post-colonial African writers, A.K. Armah and A. La Guma, inscribed within the recent trend labelled 'literature of waste'. ...Scrutinised through ecocritical and sociological theories, their works stand out for the striking way in which they provide a unique reading of the Sub-Saharan continent as remnant of neocolonialist processes that have been relegating it, both metaphorically and concretely, to a waste bin for the throwaway economies of the developed countries. Settings buried in garbage reveal themselves not only as metaphorical devices, but as literary pretexts able to open up a window on existing African nightmarish landscapes. Among them the Agbogbloshie electronic-waste dumping ground in Ghana, a receptacle of 'next-generation' rubbish originated at the heart of industrialised nations and illegally shipped to the other end of the world, where waste joins wasted humanity.
Chitosan has become a focus of major interest in recent years due to its excellent biocompatibility, biodegradability and non-toxicity. Although this material has already been extensively ...investigated in the design of different types of drug delivery systems, it is still little explored for stomach specific drug delivery systems. The objective of the present investigation was to explore the potential of low molecular mass chitosan (LMCH) as carrier for a hydrodynamically balanced system (HBS) for sustained delivery of water soluble drug ciprofloxacin hydrochloride (CP). Various formulations were prepared by physical blending of drug and polymer(s) in varying ratios followed by encapsulation into hard gelatin capsules. All the formulations remained buoyant in 0.1 mol L-1 HCl (pH 1.2) throughout the experiment. Effect of addition of xanthan gum (XG) or ethyl cellulose (EC) on drug release was also investigated. Zero order drug release was obtained from the formulations containing LMCH alone or in combination with XG, and in one instance also with EC. Our results suggest that LMCH alone or in combination with XG is an excellent material for stomach specific sustained delivery of CP from hydrodynamically balanced single unit capsules.
Zbog svoje biokompatibilnosti, biorazgradljivosti i netoksičnosti kitozan je vrlo interesantan istraživačima u području farmaceutske tehnologije. Najviše se upotrebljavao u dizajniranju različitih sustava za isporuku lijekova ali vrlo malo za sustave za specifičnu isporuku u želucu. Cilj ovog rada bio je ispitati mogućnost upotrebe kitozana male molekulske mase (LMCH) kao nosača u hidrodinamički balansiranom sustavu (HBS) za usporenu isporuku vodotopljivog lijeka ciprofloksacin hidroklorida (CP). Pripravljene su različite formulacije stvaranjem fizičke smjese lijeka i polimera u različitim omjerima, koje su potom kapsulirane u želatinske kapsule. Svi su pripravci za vrijeme cijelog eksperimenta ostali plutati u 0,01mol L1 HCl (pH 1,2). Ispitivan je i učinak ksantan gume (XG) ili etilceluloze (EC) na oslobađanje lijeka. Oslobađanje lijeka nultog reda postignuto je iz formulacija koje sadrže samo LMCH ili LMCH u kombinaciji sa XG i u jednom slučaju s EC. Dobiveni rezultati pokazuju da je LMCH, sam ili u kombinaciji sa XG, izvrstan materijal za sustave za specifičnu isporuku CP iz hidrodinamički balansiranih kapsula.
This paper examines injustice and poverty as motifs in Alex La Guma’s first three novels. A motif is a recurrent formal element in a work of art. The foundation of apartheid is injustice which often ...leads to massive poverty on the part of the non-white community whose members are hapless victims of marginalization and disfranchisement in the Republic of South Africa. The prevalence of the twin forces of injustice and poverty in apartheid South Africa which La Guma artistically portrays in his first three novels confers on them the status of a motif. This, in itself, is a function of the novelist’s deference to realism and artistic relevance. The paper discovers that the unrelenting travesty of justice and the prevalence of destitution which describe so many unsavoury scenes in the novels in focus are due to the non-whites’ lack of meaningful political consciousness which itself is a function of the racist government’s stamp on oppositional discourse. It is this vacuum that the puny and ineffective pockets of individual acts of courage attempt to fill in the three novels to no avail.
Proszek pozyskiwany z nasion karobowych, zwany inaczej mączką chleba świętojańskiego, ma szerokie zastosowanie przemysłowe. Spełnia funkcję zagęstnika, stabilizatora, w odpowiednich warunkach ...substancji żelującej oraz nośnika. Wielu konsumentów ocenia karob jako produkt, który ze względu na swój smak i aromat może niejednokrotnie stanowić substytut kakao. W klimacie śródziemnomorskim, gdzie występuje karob, mączka chleba świętojańskiego stanowi główny surowiec do produkcji słodyczy. Celem tej pracy było wskazanie możliwości wykorzystania karobu jako dodatku o działaniu prozdrowotnym i tym samym potencjalnym składniku funkcjonalnym w żywności (o znaczeniu innym niż technologiczne bądź sensoryczne).
And a Threefold Cord : La Guma's neglected masterpiece? For a variety of reasons (including its publication history), Alex la Guma's second novel And a Threefold Cord (1964) has long been neglected ...by readers and critics. This essay seeks to redress this situation by offering a reading of the novel that demonstrates its artistic integrity. Like A Walk in the Night, And a Threefold Cord avoids the overt propagandizing that arguably mars La Guma's later work. The political "message" of the text is shown to emerge organically from events that unfold in its presented world. And a Threefold Cord is set in a Cape Flats shantytown, and it analyses the predicament of the shanty dwellers in terms of class inequality and economic exploitation, rather than in terms of racial discrimination. This ensures the novel's continuing relevance in a South Africa where far too many people are inadequately housed in ever-growing "informal settlements".
Readers have frequently remarked and commended the 'gritty realism' of Alex La Guma's evocation of District Six and other Cape 'slumscapes'. But in1974 J.M. Coetzee published an important dissenting ...essay ('Man's Fate in the Novels of Alex La Guma') in which he described La Guma as 'the inheritor of the worst excesses of realism'. The overall effect of the meticulously detailed representation of setting was not verisimilitude but 'literariness itself'. Thus 'La Guma's world, so overflowing with things, is... not an objective world, for the things themselves are overflowing with the writer's subjectivity'. This essay engages with this critical judgment, focusing on La Guma's novella, A Walk in the Night, and arguing that La Guma's descriptive style is justifiable in terms of a'Socialist Realist' aesthetic that gives vital expression to the materialist premise informing his Marxist view of the human condition.
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