PESTICIDES: AN OVEREVIEW

The majority of the farmers are unaware of pesticide types, a level of poisoning, safety precautions and potential hazards on health and environment. According to the latest estimate, the annual import of pesticides in Nepal is about 211t a.i. with 29.19% insecticides, 61.38% fungicides, 7.43% herbicides and 2% others. The gross sale value accounts the US $ 3.05 million per year. Average pesticides use in Nepal is 142 g a.i./ha, which is very low as compared to other Asian countries. Pesticidal misuse is being a serious concern mainly in the commercial pocket areas of agricultural production, where farmers are suffering from environmental pollution. An incidence of poisoning is also increasing because of intentional, incidental and occupational exposure. Toxic and environmentally persistent chemicals are being used as pesticides. Many studies showed that the chemical pollution of the environment has long-term effects on human life. It is therefore essential that manufacture, use, storage, transport and disposal of chemical pesticides be strictly regulated. Keywords: Environment, Human-health, Misuse, Pesticides, Pesticide-consumption Â

Preparation and Evaluation of Sulfacetamide Sodium Ocusert for Controlled Drug Delivery

The intent of this research was to formulate and evaluate controlled release ocusert of sulfacetamide sodium for the treatment of bacterial conjunctivitis. Ocusert is a sterile preparation having drug as dispersion or as solution in the polymeric base. Prepared Ocuserts were formulated using hydroxyl propyl methyl cellulose K-15 and Ethyl cellulose as polymers at various concentrations and combinations. Polymeric Films were prepared by mercury casting method using different ratios of polymers. Selected physiochemical properties such as thickness, weight, percentage moisture absorption, and in-vitro release and sterility studies of sulfacetamide sodium ocusert were studied and reported that prepared ocusert resolved the problems of poor bioavailability, frequent dosing and wastage of active ingredient. Keywords: Hydroxypropyl methyl cellulose K-15, ocusert, sulfacetamide sodiu

A REVIEW ON DISINTEGRATION CONTROL MATRIX TABLETS

A number of sustained release formulations are available in the market which successfully sustained the drug release over a prolonged period of time by different mechanisms. The new approach for sustaining the drug release is disintegration control matrix tablet which sustained the drug release up to 24hrs by controlling the disintegration rate of tablet. Disintegration control matrix tablet (DCMT) mainly forms the granules containing drug and disintegrating agent such as low substituted hydroxyl propyl cellulose by various methods such as solid dispersion technique. The sustained release of drug is maintained by increasing the wax coating or decreasing the amount of disintegrants. The release of drug from tablet is uniform throughout till all the drug releases from tablet as it involves drug release by diffusion, dissolution and surface erosion mechanism. DCMT increases the solubility of drug and improves the bioavailability without disturbing gastrointestinal transit. BCS Class II, III, IV drugs are the best candidate for DCMT formulations. Keywords: Disintegration control matrix tablet (DCMT), Wax, Disintegrating agent, Solid dispersion

Nanosuspensions as a promising approach to enhance bioavailability of poorly soluble drugs : An update

Solubility is a vital factor for devloping drug delivery systems for poorly water soluble drugs. Several conventional approaches for enhancement of solubility have limited applicability, especially when the drugs are poorly water soluble. Nanosuspension technology can be used to enhance the solubilty, stability as well as the bioavailability of poorly water soluble drugs. Nanosuspensions are biphasic systems comperising of pure drug particles dispersed in an aqueous vehicle, stabilized by surfac active agents. Fabrication of nanosuspension is simple and more advantageous than other approaches. Techniques like high-pressure homogenization, wet milling, emulsification, solvent evaporation, bottom up technology and top down technology have been applicable in the fabrication of nanosuspensions. Nanosuspension delivery is possible by several routes, such as oral, pulmonary, parenteral and ocular routes. Nanosuspension not only solves solubility and bioavailability issue, but improve drug safety and efficacy. In this context, we reviewed the current techniques used to develop nanosuspensions and their recents studies application in drug delivery system. Keywords : Solubility, fabrication, Characterization, Applications, Nanosuspension

A REVIEW ON FUNCTIONAL COMPARISON OF 5-HT1A AND 5-HT2C RECEPTORS

5-HT neurotransmission system is targeted by drugs useful in behavioural disorders, including anxiety, depression, psychosis and eating disorders. 5-HT1A autoreceptors, located on 5-HT neurones of the midbrain raphe nuclei, are coupled to K channels through a pertusis toxin-sensitive G-protein. 5-HT1A receptor agonists inhibit adenylyl cyclase, while 5-HT2C receptor agonists activate two signal transduction pathways coupled with these receptors. 5-HT1A and 5-HT2C receptors have lots potential in treating the disorders with less or no side effects. Keywords: 5-HT1A, 5-HT2C, Receptor

BIOADHESIVE MULTIPARTICULATE (MICROSPHERS) DRUG DELIVERY SYSTEM: A REVIEW

The concept of controlled drug delivery has been traditionally used to obtain specific release rates or targeting of active ingredients. The phenomenon of bioadhesion has been studied extensively in the last decade and applied to improve the performance of these drug delivery systems. Recent advances in polymer science and drug carrier technologies have promulgated the development of novel drug carriers such as bioadhesive microspheres that have boosted the use of “bioadhesion†in drug delivery. This article presents the spectrum of potential applications of bioadhesive microspheres in controlled drug delivery ranging from the small molecules, to peptides, and to the macromolecular drugs such as proteins, oligonucleotides and even DNA. The development of mucus or cell-specific bioadhesive polymers and the concepts of cytoadhesion and bioinvasion provide unprecedented opportunities for targeting drugs to specific cells or intracellular compartments. Developments in the techniques for in vitro and in vivo evaluation of bioadhesive microspheres have also been discussed. Keywords: - Bioadhesion, Bioadhesive Microspheres, Development, Polymers

PHYTOCHEMICAL INVESTIGATION AND IN VITRO ANTIMICROBIAL SCREENING OF SANTALUM ALBUM SEEDS EXTRACTS

Objective: Present study aimed phytochemical evaluation and antimicrobial screening of petroleum ether and ethanol extracts of Santalum album seeds.Methods: Petroleum ether and ethanol extracts were screened for presence of chemical constituents. Petroleum ether extract was investigated detail by using chromatographic and spectroscopic methods. In vitro antimicrobial activity of both extracts were investigated using disc diffusion method on two gram-positive bacteria, Bacillus subtilis, Staphylococcus aureus, gram negative Pseudomonas aeruginosa, Escherichia coli and fungus Candida albicans.Results: Santalbic acid was identified in petroleum ether extract and content determined by HPTLC was 4.7%w/w. It was seen that petroleum ether extract have MIC value for B. subtilis, P. aeruginosa, E. coli and C. albicans were 78.125 µg/ml, 19.331 µg/ml, 625 µg/ml & 39.062 µg/ml respectively while MBC was 39.062 µg/ml, 4.882 µg/ml, 312.5 µg/ml & 9.765 µg/ml,  respectively. Petroleum ether extract showed MIC and MBC values for S. aureus was similar as 156.25µg/ml. So, the petroleum ether extract showed significant antimicrobial activity against both gram positive, gram negative and fungal strain.Conclusions: The results of present investigations were indicative of possible high potency of petroleum ether extract due to santalbic acid which could serve as chemotherapeutic agent