SELF-MICROEMULSIFYING DRUG DELIVERY SYSTEM

ABSTRACTOral route is the most convenient route of drug administration in many diseases and till today it is the first way investigated in the development ofnew dosage forms. The major problem in oral drug formulations is low and erratic bioavailability, which mainly results from poor aqueous solubility,thereby pretense problems in their formulation. More than 40% of potential drug products suffer from poor water solubility. For the therapeuticdelivery of lipophilic active moieties (biopharmaceutical classification system Class II drugs), lipid-based formulations are inviting increasingattention. Currently, a number of technologies are available to deal with the poor solubility, dissolution rate, and bioavailability of insoluble drugs.One of the promising techniques is self-microemulsifying drug delivery systems (SMEDDS). SMEDDS have gained exposure for their ability to increasesolubility and bioavailability of poorly soluble drugs. SMEDDS, which are isotropic mixtures of oils, surfactants, solvents, and co-solvents/surfactantscan be used for the design of formulations to improve the oral absorption of highly lipophilic drug compounds. Conventional SMEDDS are mostlyprepared in a liquid form, which can have some disadvantages. SMEDDS can be orally administered in soft or hard gelatin capsules and form finerelatively stable oil-in-water emulsions. Solid-SMEDDS are prepared by solidification of liquid/semisolid self-micron emulsifying ingredients intopowders, have gained popularity. This article gives a complete overview of SMEDDS, but special attention has been paid to formulation, design,evaluation, and little emphasis on application of SMEDDS.Keywords: Self-microemulsifying drug delivery system, Surfactant, Oil, Co-surfactant, Bioavailability, Lipophilic, Biopharmaceutical classificationsystem Class II drugs

INTEND, DEPICTION IN VITRO AND IN VIVO APPRAISAL OF GLIPIZIDE FLOATING MICROSPHERES USING ETHYL CELLLULOSE AND HYDROXYL PROPYL METHYL CELLULOSE AS POLYMER BY SUBSTANTIALLY MODIFIED METHOD

Objective: The purpose of this research was to formulate and evaluate floating microsphere of glipizide.Methods: Glipizide microsphere containing ethyl cellulose (EC) and hydroxyl propyl methyl cellulose (HPMC) were prepared by solvent evaporationmethod. Polymer to drug ratio affected characteristics of microspheres. Microspheres were discrete, spherical, and perforated form. The microspheresexhibited good floating property and achieved good gastric retention.Result: In vitro performance was evaluated by the usual pharmacopoeial and other tests such as drug polymer compatibility (Fourier transforminfrared scan), yield (%), micrometric properties such as tapped density (%). Compressibility particle size analysis (by optical microscopy), drugentrapment efficiency, surface topography (scanning electron microscope), and in vitro release study. On the basis of results, increasing the polymerratio increased the particle size (195.6±20.24 to 200.89±16.61), increased tapped density (maximum 0.29.60±0.00037 HGF4, batch), and decreased% compressibility (2.13±0.188). Drug loaded floating microspheres were found to be float more than 12 hrs on simulated gastric fluid (pH-1.2).Maximum drug entrapment was found in batch HGF3 (Drug:HPMC:EC) (1:1:3). Electron microscopy showed its perforated surface with hollowness.After 10 hrs, maximum release was found to be 78.0% (batch-GF1).Conclusion: The release study was performed in simulated gastric fluid with 0.02% tween80. The best release result was obtained at the ratio ofdrug: polymer (1:1).Keywords: Floating microspheres, Glipizide, Gastrorentensive system, In vitro release

Pharmacognostic and phytochemical evaluation of the Solanun sisymbriifolium leaf

Solanum sisymbriifolium Lam. (Solanaceae) is an important medicinal herb in Ayurvedic medicine. In the present investigation, the detailed pharmacognostic study of S. sisymbriifolium leaf was carried out to lay down the standards which could be useful in future experimental studies. The study included macroscopy, microscopy, preliminary phytochemical screening and physicochemical evaluation. These observations will help in the Pharmacognostical identification and standardization of the drug in the crude form and also to distinguish the drug from its adulteration.Keywords: Solanum sisymbriifolium, pharmacognosy, microscopy.African Journal of Biotechnology Vol. 12(42), pp. 6133-613

The role of carbon in life's blueprint and carbon cycle understanding earth's essential cycling system: benefits and harms to our planet

This abstract provides a concise overview of carbon, carbon dioxide, and the carbon cycle. Carbon is an essential element for life on Earth, serving as the building block of organic molecules found in living organisms. Carbon dioxide (CO2), a greenhouse gas, plays a dual role in supporting life through photosynthesis while also contributing to climate change when its concentration in the atmosphere increases due to human activities. The carbon cycle is a natural process that continuously cycles carbon between the atmosphere, oceans, land, and living organisms. It plays a vital role in regulating the Earth's climate, supporting plant growth through photosynthesis, sequestering carbon in natural sinks, and sustaining various ecosystems. However, human activities have disrupted the carbon cycle, leading to adverse effects such as climate change, ocean acidification, and ecosystem disturbances. Mitigating these harmful impacts requires global efforts to reduce carbon emissions, conserve forests, and adopt sustainable practices to restore the balance of the carbon cycle and ensure a more sustainable future

Testing the Waste Based Biorefinery Concept: Pilot Scale Cultivation of Microalgal Species on Spent Anaerobic Digestate Fluids

PurposeA waste based biorefinery approach has been tested.MethodsThis has been investigated by culturing in a 800 L photobioreactor two autotrophic microalgae namely Nannochloropsis oceanica and Scenedesmus quadricauda utilising filtered spent anaerobic digestate fluids of N:P ratio 14.22 as substrate.ResultsSignificant rates of bioremediation simultaneously with biomass and associated end product formation were achieved. Nitrogen and phosphorus of waste based media was decreased up to 90%. The biomass biochemical analysis of the microalgae when grown on the waste based formulated media demonstrated the comparable content of lipids and proteins with the species grown on f/2 media.ConclusionsTheoretical biomethane potential generation, should the algal cultures be placed in an anaerobic digester, was calculated at 0.58 L CH4 g−1 VS for N. oceanica and 0.48 L CH4 g−1 VS for S. quadricauda showing comparable results with other studies of different source of biomass

Plasmodium vivax lineages: geographical distribution, tandem repeat polymorphism, and phylogenetic relationship

<p>Abstract</p> <p>Background</p> <p>Multi-drug resistance and severe/complicated cases are the emerging phenotypes of vivax malaria, which may deteriorate current anti-malarial control measures. The emergence of these phenotypes could be associated with either of the two <it>Plasmodium vivax </it>lineages. The two lineages had been categorized as Old World and New World, based on geographical sub-division and genetic and phenotypical markers. This study revisited the lineage hypothesis of <it>P. vivax </it>by typing the distribution of lineages among global isolates and evaluated their genetic relatedness using a panel of new mini-satellite markers.</p> <p>Methods</p> <p><it>18S SSU rRNA S-type </it>gene was amplified from 420 <it>Plasmodium vivax </it>field isolates collected from different geographical regions of India, Thailand and Colombia as well as four strains each of <it>P. vivax </it>originating from Nicaragua, Panama, Thailand (Pak Chang), and Vietnam (ONG). A mini-satellite marker panel was then developed to understand the population genetic parameters and tested on a sample subset of both lineages.</p> <p>Results</p> <p><it>18S SSU rRNA S-type </it>gene typing revealed the distribution of both lineages (Old World and New World) in all geographical regions. However, distribution of <it>Plasmodium vivax </it>lineages was highly variable in every geographical region. The lack of geographical sub-division between lineages suggests that both lineages are globally distributed. Ten mini-satellites were scanned from the <it>P. vivax </it>genome sequence; these tandem repeats were located in eight of the chromosomes. Mini-satellites revealed substantial allelic diversity (7-21, <it>AE </it>= 14.6 ± 2.0) and heterozygosity (<it>He </it>= 0.697-0.924, <it>AE </it>= 0.857 ± 0.033) per locus. Mini-satellite comparison between the two lineages revealed high but similar pattern of genetic diversity, allele frequency, and high degree of allele sharing. A Neighbour-Joining phylogenetic tree derived from genetic distance data obtained from ten mini-satellites also placed both lineages together in every cluster.</p> <p>Conclusions</p> <p>The global lineage distribution, lack of genetic distance, similar pattern of genetic diversity, and allele sharing strongly suggested that both lineages are a single species and thus new emerging phenotypes associated with vivax malaria could not be clearly classified as belonging to a particular lineage on basis of their geographical origin.</p

Molecular surveillance of Plasmodium vivax dhfr and dhps mutations in isolates from Afghanistan

<p>Abstract</p> <p>Background</p> <p>Analysis of dihydrofolate reductase (<it>dhfr</it>) and dihydropteroate synthase (<it>dhps</it>) mutations in <it>Plasmodium vivax </it>wild isolates has been considered to be a valuable molecular approach for mapping resistance to sulphadoxine-pyrimethamine (SP). The present study investigates the frequency of SNPs-haplotypes in the <it>dhfr </it>and <it>dhps </it>genes in <it>P. vivax </it>clinical isolates circulating in two malaria endemic areas in Afghanistan.</p> <p>Methods</p> <p><it>P. vivax </it>clinical isolates (n = 171) were collected in two different malaria endemic regions in north-west (Herat) and east (Nangarhar) Afghanistan in 2008. All collected isolates were analysed for SNP-haplotypes at positions 13, 33, 57, 58, 61, 117 and 173 of the <it>pvdhfr </it>and 383 and 553 of the <it>pvdhps </it>genes using PCR-RFLP methods.</p> <p>Results</p> <p>All 171 examined isolates were found to carry wild-type amino acids at positions 13, 33, 57, 61 and 173, while 58R and 117N mutations were detected among 4.1% and 12.3% of Afghan isolates, respectively. Based on the size polymorphism of <it>pvdhfr </it>genes at repeat region, type B was the most prevalent variant among Herat (86%) and Nangarhar (88.4%) isolates. Mixed genotype infections (type A/B and A/B/C) were detected in only 2.3% (2/86) of Herat and 1.2% (1/86) of Nangarhar isolates, respectively. The combination of <it>pvdhfr </it>and <it>pvdhps </it>haplotypes among all 171 samples demonstrated six distinct haplotypes. The two most prevalent haplotypes among all examined samples were wild-type (86%) and single mutant haplotype I₁₃P₃₃F₅₇S₅₈T₆₁<b>N </b>₁₁₇I_173/A₃₈₃A₅₅₃(6.4%).</p> <p>Double (I₁₃P₃₃S₅₇<b>R</b>₅₈T₆₁<b>N</b>₁₁₇I₁₇₃/A₃₈₃A₅₅₃) and triple mutant haplotypes (I₁₃P₃₃S₅₇<b>R </b>₅₈T₆₁<b>N</b>₁₁₇I₁₇₃/<b>G</b>₃₈₃A₅₅₃) were found in 1.7% and 1.2% of Afghan isolates, respectively. This triple mutant haplotype was only detected in isolates from Herat, but in none of the Nangarhar isolates.</p> <p>Conclusion</p> <p>The present study shows a limited polymorphism in <it>pvdhfr </it>from Afghan isolates and provides important basic information to establish an epidemiological map of drug-resistant vivax malaria, and updating guidelines for anti-malarial policy in Afghanistan. The continuous usage of SP as first-line anti-malarial drug in Afghanistan might increase the risk of mutations in the <it>dhfr </it>and <it>dhps </it>genes in both <it>P. vivax </it>and <it>Plasmodium falciparum </it>isolates, which may lead to a complete SP resistance in the near future in this region. Therefore, continuous surveillance of <it>P. vivax </it>and <it>P. falciparum </it>molecular markers are needed to monitor the development of resistance to SP in the region.</p