3 research outputs found

    Nanotechnology based drug delivery systems for the treatment of anterior segment eye diseases

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    Diseases affecting the anterior segment of the eye are the primary causes of vision impairment and blindness globally. Drug administration through the topical ocular route is widely accepted because of its user/patient friendliness - ease of administration and convenience. However, it remains a significant challenge to efficiently deliver drugs to the eye through this route because of various structural and physiological constraints that restrict the distribution of therapeutic molecules into the ocular tissues. The bioavailability of topically applied ocular medications such as eye drops is typically less than 5%. Developing novel delivery systems to increase the retention time on the ocular surfaces and permeation through the cornea is one of the approaches adopted to boost the bioavailability of topically administered medications. Drug delivery systems based on nanotechnology such as micelles, nanosuspensions, nanoparticles, nanoemulsions, liposomes, dendrimers, niosomes, cubosomes and nanowafers have been investigated as effective alternatives to conventional ocular delivery systems in treating diseases of the anterior segment of the eye. This review discussed different nanotechnology-based delivery systems that are currently investigated for treating and managing diseases affecting the anterior ocular tissues. We also looked at the challenges in translating these systems into clinical use and the prospects of nanocarriers as a vehicle for the delivery of phytoactive compounds to the anterior segment of the eye

    Effect of molecular interaction on the antiplasmodial efficacy of lumefantrine in amorphous polymethacrylate-urea solid solution

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    Malaria, a leading cause of mortality and morbidity in the developing world, with children aged under 5 years, accounts for 61% of all the global malaria deaths. The World Health Organization approved fixed-dose first-line artemisinin-based combination therapy (ACT) – artemether-lumefantrine for effective malaria treatment, is challenged by poor aqueous solubility and inadequate bioavailability leading to treatment failures and emergence of resistant strains. This study focuses on evaluating novel lumefantrine (LF) polymethacrylate-urea solid solutions comprising of a retarding polymer for enhanced anti-plasmodial efficacy comparable with existing artemether-lumefantrine combination therapy. Lumefantrine polymethacrylate-urea solid solutions were prepared by solvent evaporation and characterized by differential scanning calorimetry (DSC), and dissolution studies. In vivo anti-plasmodial activity was determined by measuring the schizonticidal activity of Plasmodium berghei-infected mice using the Peter’s 4-day curative test and the safety of the solid solutions was tested in major organs implicated in malaria. The solid state characterizations confirmed the formation of amorphous lumefantrine polymethacrylate-urea solid solutions. There was greater drug release from the matrix polymer in acidic than basic biorelevant media, with release kinetics following the Higuchi order. Interestingly, the reduction in parasitaemia caused by the lumefantrine polymethacrylate-urea formulations (72.3 and 81.27 %) for ternary and quaternary systems, batches SDA3 and SDB3, respectively) were significantly higher (p < 0.05) and more sustained than lumefantrine pure powder, but with comparable efficacy to the commercial brand-Coartem®. The formulation was stable over a period of 6 months. Thus, this study provides useful information on developing sustained lumefantrine formulation with improved solubility and antiplasmodial efficacy. Keywords: Solid dispersion, lumefantrine, solubility, parasitaemia reduction, eudragit polymer, Urea

    Quinine: Redesigned and Rerouted

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    Quinine hydrochloride (QHCl) has remained a very relevant antimalarial drug 400 years after its effectiveness was discovered. Unlike other antimalarials, the development of resistance to quinine has been slow. Hence, this drug is to date still used for the treatment of severe and cerebral malaria, for malaria treatment in all trimesters of pregnancy, and in combination with doxycycline against multidrug-resistant malaria parasites. The decline in its administration over the years is mainly associated with poor tolerability due to its gastrointestinal (GIT) side effects such as cinchonism, complex dosing regimen and bitter taste, all of which result in poor compliance. Hence, our research was aimed at redesigning quinine using nanotechnology and investigating an alternative route for its administration for the treatment of malaria. QHCl nanosuspension (QHCl-NS) for intranasal administration was prepared using lipid matrices made up of solidified reverse micellar solutions (SRMS) comprising Phospholipon® 90H and lipids (Softisan® 154 or Compritol®) in a 1:2 ratio, while Poloxamer® 188 (P188) and Tween® 80 (T80) were used as a stabilizer and a surfactant, respectively. The QHCl-NS formulated were in the nanosize range (68.60 ± 0.86 to 300.80 ± 10.11 nm), and highly stable during storage, though zeta potential was low (≤6.95 ± 0.416). QHCl-NS achieved above 80% in vitro drug release in 6 h. Ex vivo permeation studies revealed that formulating QHCl as NS resulted in a 5-fold and 56-fold increase in the flux and permeation coefficient, respectively, thereby enhancing permeation through pig nasal mucosa better than plain drug solutions. This implies that the rate of absorption as well as ease of drug permeation through porcine nasal mucosa was impressively enhanced by formulating QHCl as NS. Most importantly, reduction in parasitaemia in mice infected with Plasmodium berghei ANKA by QHCl-NS administered through the intranasal route (51.16%) was comparable to oral administration (52.12%). Therefore, redesigning QHCl as NS for intranasal administration has great potential to serve as a more tolerable option for the treatment of malaria in endemic areas