Nanotechnology and Drug Delivery Part 1: Background and Applications

Nanotechnology in general and as it relates to drug delivery in humans has been reviewed in a two-part article, the first part of which is this paper. In this paper, nanotechnology in nature, history of nanotechnology and methods of synthesis are discussed, while also outlining its applications, benefits and risks. Nanotechnology is an industrial revolution, based on integration of disciplines that could change every facet of human life. Some examples ofchanges brought about by reduction in particle sizes to the physical, chemical and biological properties of substances, compounds and drug products have been cited. The benefits of nanotechnology are enormous and so these benefits should be maximized while efforts are made to reduce the risks

Nanotechnology and Drug Delivery Part 2: Nanostructures for Drug Delivery

This is the second part of a review on nanotechnology in general and particularly as it pertains to drug deliver. In the earlier paper (Part 1), nanotechnology in nature, its history as well as design and methodswere discussed. Its applications, benefits and risks were also outlined. In this paper (Part 2), various nanostructures employed in drug delivery, their methods of fabrication and challenges of nano drug delivery are reviewed. Nanotechnology is one approach to overcome challenges of conventional drugdelivery systems based on the development and fabrication of nanostructures. Some challenges associated with the technology as it relates to drug effectiveness, toxicity, stability, pharmacokinetics and drug regulatory control are discussed in this review. Clearly, nanotechnology is a welcomedevelopment that is set to transform drug delivery and drug supply chain management, if optimally developed

An assessment of pharmaceutical waste management in some Nigerian pharmaceutical industries

Thirty four (34) of the fifty (50) selected Nigerian based pharmaceutical businesses, mainly acting as local manufacturers and major importers of medicines were interviewed using questionnaires to ascertain their waste management practices, knowledge of waste management policies and subjection to regulatory control. This study indicated that like its counterpart industry in other countries of the world, the Nigerian pharmaceutical industry generated both hazardous and non-hazardous wastes. However, the wastes were not categorized, poorly managed by 91.2% of the respondents, while 58.8% of the health and safety personnel had little or no modern knowledge of waste management. Furthermore, 73.5% of the respondents claimed that they were aware of the regulatory requirements on waste, but no adherence was observed. The industry did not benefit from the strict supervisions of regulatory agencies. Pharmaceutical waste was improperly disposed and all the secondary manufacturers (79.4%) discharged wastewater without removal of pharmaceuticals. This study highlighted the urgent need to train personnel in the pharmaceutical industry and regulatory authorities. Management of waste should be planned, documented, implemented and sustained.Key words: Pharmaceutical waste, pharmaceuticals, wastewater, waste management, environment, regulatory authorities, effluent

Waste management in healthcare establishments within Jos Metropolis, Nigeria

Poor management of healthcare waste exposes health workers and the public to the toxic effects of wastes generated from health establishments. The disposal of these wastes could also lead to environmental problems if not done properly. This study has assessed the waste management practices in hospitals and compared same with international standards. A survey was carried out in six major hospitals in Jos metropolis. The findings indicated that these hospitals fell below the recommended waste management practices as prescribed by World Health Organization and other regulatory authorities. Wastes were not segregated, and were inappropriately disposed. The health workers were unaware of relevant regulations and the existence of a hospital waste management policy. Recommendations have been made for staff training to create awareness on wastes, their effects, importance of existing guidelines and the implementation of the waste management options for the different categories of wastes so that hospitals do not become infection centres that contribute to the damage of both the environment and human health

Hypoglycemic effects of the aqueous extract of African Mistletoe, Tapinanthus sesselifolius (P. Beauv) van Tiegh (Loranthaceae)

The hypoglycemic effect of the aqueous extract of African mistletoe, Tapinanthus sesselifolius, was investigated in-vivo and in-vitro. Studies were carried out on normoglycemic and alloxan-induced hyperglycemic rabbits, and glucose uptake studies were done using the isolated intestine of normal rabbits. The safety studies (acute toxicity test) were carried out in mice. The results revealed that the aqueous extract of Tapinanthus sesselifolius exhibited transient reduction of blood glucose in normoglycemic rabbits and significantly lowered blood glucose level in hyperglycemic rabbits. The extract significantly decreased the level of glucose in serosal fluid dose dependently. The intraperitoneal (i.p.) LD50 of Tapinanthus sesselifolius was found to be 2000 – 2650 mg/kg within 95% confidence limits. The preliminary phytochemical screening showed positive test for biologically active substances such as saponins, tannins, flavonoids, terpenoids and glycosides. The data showed that Tapinanthus sesselifolius contain biologically active substances that may be useful in treatment of diabetes and thus gave a scientific basis for its use in herbal traditional medicine as an antidiabetic agent.Keywords: Phytomedicine, alloxan-induced hyperglycemia, glucose uptak

Effects of Extraction Method on the Physicochemical and Mycological Qualities of Canarium Schweinfurthii Fruit Oil

The effects of improved method of extraction on the physicochemical, mycological and stability of crude Canarium Schweinfurthii fruit oil were studied. The extracted oils were then stored at 25±5oC for 24 months with samples analyzed at 6months interval for; pH, saponification value, acid value, peroxide value and iodine number. Similarly, enumeration and identification of fungi species was determined using standard mycological procedures. The results showed that crude Canarium Schweinfurthii fruit oil obtained by the improved method of extraction had better quality and stability parameters than the traditional method extracted oil. At 24months the oil quality values of; pH 5.20 – 6.61, Acid value 0.53 – 1.02 (mg of KOH/g), saponification value 151.30 – 179.52 (mg of OH/g), peroxide value 0.031 – 1.500 (meq 02/Kg) and iodine value 85.02 – 101.60 (gI2/100g). Comparatively, no significant difference (P > 0.05) was observed for pH and saponification values for the extracted oils, with values of 6.60, 178.60(mg of OH/g) and 6.62, 178.52(mg of OH/g) for traditional and improved extraction methods respectively. During storage the oils showed average fungal counts of 00.00 to 1.72 x105 and 00.00 to 8.00 x104 CFU/ml oil at 0 and 24 month for traditional and improved methods extracted oils respectively. Predominant fungal species; Aspergillus niger, Rhizopus stolonifer, Sacccaromyces cerevisiae, Mucor spinosus, Penicillium patalun, Fusarium oxysprum and Candida scotti were found associated with the stored canarium oil. Generally, Mucor spinosus (80.00%), Aspergillus niger (80.00%) and Penicillium patalum (80.00%) had the highest occurrence in traditional extracted oil. This finding  suggests the need for the local processors to reevaluate the full processing method in order to retain better fungal quality and oxidative stability for Canarium schweinfurthii fruit oil.Keywords: Canarium schweinfurthii, fruit oil, Extraction, Fungal Isolates, Oxidative stabilit

Eudragit E100 and Polysaccharide Polymer Blends as Matrices for Modified-Release Drug Delivery II: Swelling and Release Studies

Purpose: To compare the effects of two states of polymer/polymer blending (dry and aqueous/lyophilized) of locust bean gum with Eudragit® E100 and sodium carboxymethylcellulose on swelling and drug (levodopa) release from their tablet matrices.Methods: Sodium carboxymethylcellulose (SCMC), Eudragit® (E100) and locust bean (LB) were blended in their dry (as purchased) state or modified by aqueous blending and subsequent lyophilization prior to use as tablet matrices. The tablets were evaluated for swelling and in vitro drug release. Furthermore, in vivo absorption was predicted from the in vitro release data by convolution method.Results: E100 matrices exhibited little or no swelling while the matrices of SCMC and LB and their blends exhibited a degree of swelling > 180 %. Aqueous blending and lyophilization modulated the rate of release from matrices formulated with LB, SCMC and their polymer/polymer blends. Drug release profiles of the lyophilized polymer/polymer blends matrices were dissimilar to those of the dry polymer/polymer blends. Formulations F1aq, F2aq and F3aq exhibited fairly uniform absorption in the first 8 h, indicating the possibility of producing a steady delivery of drug.Conclusion: Polymer blending of LB, SCMC and E100, achieved by aqueous blending and lyophilization, enhances the performance of the matrices thereby exhibiting controlled levodopa release with no burst effect and the tablets retained their three-dimensional network.Keywords: Controlled release, Drug delivery, Eudragit, Locust bean, Levodopa, Matrix, Polymer blend, Sodium carboxymethylcellulos

Eudragit E100 and Polysaccharide Polymer Blends as Matrices for Modified-Release Drug Delivery I: Physicomechanical Properties

Purpose: To compare the effects of two states of polymer/polymer blending (dry and aqueous/lyophilized) on the physicomechanical properties of tablets, containing blends of locust bean gum (LB) with Eudragit® E100 (E100) and sodium carboxymethylcellulose (SCMC) as matrices.Methods: LB, SCMC and E100 were blended in their dry (as purchased) state or modified by aqueous blending and subsequent lyophilization, prior to use as matrices in tablets. The polymer blends were characterized by infra-red spectroscopy (FTIR), flow and compressibility tests, as well as physicomechanical analysis of their tablets.Results: No significant variations were noticeable in the FTIR peaks of the individual polymers in the dry and the aqueous/lyophilized states. Aqueous/lyophilized blending of the polymers resulted in better flow properties. The aqueous/lyophilized matrices were denser with improved mechanical strength and the tablets were harder than those produced from dry blended polymers.Conclusion: Dry blending of LB with E100 and SCMC greatly improved the physicomechanical properties of the tablets. This was further enhanced by aqueous/lyophilized blending.Keywords: Drug delivery, Polymer blend, Eudragit, Locust bean gum, Levodopa, Sodium carboxymethylcellulose, Matrix, Physicomechanical propertie

New potential antitumoral fluorescent tetracyclic thieno[3,2-b]pyridine derivatives: interaction with DNA and nanosized liposomes

Fluorescence properties of two new potential antitumoral tetracyclic thieno[3,2-b]pyridine derivatives were studied in solution and in liposomes of DPPC (dipalmitoyl phosphatidylcholine), egg lecithin (phosphatidylcholine from egg yolk; Egg-PC) and DODAB (dioctadecyldimethylammonium bromide). Compound 1, pyrido[2',3':3,2]thieno[4,5-d]pyrido[1,2-a]pyrimidin-6-one, exhibits reasonably high fluorescence quantum yields in all solvents studied (0.20 ≤ ΦF ≤ 0.30), while for compound 2, 3-[(p-methoxyphenyl)ethynyl]pyrido[2',3':3,2]thieno[4,5-d]pyrido[1,2-a]pyrimidin-6-one, the values are much lower (0.01 ≤ ΦF ≤ 0.05). The interaction of these compounds with salmon sperm DNA was studied using spectroscopic methods, allowing the determination of intrinsic binding constants, Ki = (8.7 ± 0.9) × 103 M-1 for compound 1 and Ki = (5.9 ± 0.6) × 103 M-1 for 2, and binding site sizes of n = 11 ± 3 and n = 7 ± 2 base pairs, respectively. Compound 2 is the most intercalative compound in salmon sperm DNA (35%), while for compound 1 only 11% of the molecules are intercalated. Studies of incorporation of both compounds in liposomes of DPPC, Egg-PC and DODAB revealed that compound 2 is mainly located in the hydrophobic region of the lipid bilayer, while compound 1 prefers a hydrated and fluid environment

Nanotechnology and the Treatment of HIV Infection

Suboptimal adherence, toxicity, drug resistance and viral reservoirs make the lifelong treatment of HIV infection challenging. The emerging field of nanotechnology may play an important role in addressing these challenges by creating drugs that possess pharmacological advantages arising out of unique phenomena that occur at the “nano” scale. At these dimensions, particles have physicochemical properties that are distinct from those of bulk materials or single molecules or atoms. In this review, basic concepts and terms in nanotechnology are defined, and examples are provided of how nanopharmaceuticals such as nanocrystals, nanocapsules, nanoparticles, solid lipid nanoparticles, nanocarriers, micelles, liposomes and dendrimers have been investigated as potential anti-HIV therapies. Such drugs may, for example, be used to optimize the pharmacological characteristics of known antiretrovirals, deliver anti-HIV nucleic acids into infected cells or achieve targeted delivery of antivirals to the immune system, brain or latent reservoirs. Also, nanopharmaceuticals themselves may possess anti-HIV activity. However several hurdles remain, including toxicity, unwanted biological interactions and the difficulty and cost of large-scale synthesis of nanopharmaceuticals