http://dr.lib.sjp.ac.lk/handle/123456789/923 Wed, 07 Jan 2026 20:15:20 GMT 2026-01-07T20:15:20Z http://dr.lib.sjp.ac.lk/handle/123456789/962 Formulation of Extended Release Theophylline Tablets Experimental, Modelling and Bioequivalence Studies Herath, K.K.G.M.P.B.; Abeysekera, A.M.; Goonethileke, A.K.E. Extended release drugs formulations are intended to continuously release medication over a prolonged period, after a single dose. Drugs which have a narrow therapeutic window and a moderate half life are good candidates for such formulations. One approach to such formulations is to embed the drug in a matrix which 'would act as a release retardant. We describe here our studies on the formulations of an extended release theophylline tablet using polymer matrices. Different acrylate copolymers sold in the market under the "Eudragit" label were subjected to experiment. Microcrystalline cellulose and calcium sulphate dihydrate were used as filler excepients. The theophylline release patterns of the different formulations were studied, at 37aC in phosplate buffers. The theophylline concentration were measured by Ul/ absorption spectroscopy A careful study of the release patterns of different formulations let to a formulation using Eudragit=E RSPO, a trimenthylammonioethyl methacrylate copolymer and calcium sulphate dihydrate, which conformed with the following release pattern in accordance with USP 25. Time (hours) % Drug Released 1 10 - 30 2 30 - 55 4 55 - 80 8 >80 This formulations 'was used to prepare tablets with two dosages, paediatric dose (125 mg) and adult dose (250 mg). The adult dose was subjected to a bioequivalence study against an established commercially available slow release 250 mg formulation (Neulin 250 SR, 3M Pharmaceuticals, Australia) Twenty healthy male volunteers participated in the study. Theophylline concentrations in serum were determined by Fluorescence Polarization Immunoassay. There was no significant difference between the two formulations in basic bio availability and pharmacokinetic parameters (AUC CiliaIa'nd Tlllal The new Theophylline ER 125 mgformulation developed is nOH'being manufactured by the State Pharmaceutical Manufacturing Corporation (SPMC). a. State Pharmaceutical Manufacturing Corporation, Sri Johne Kothalawala Estate, Ratmalana, Sri Lanka 071-1815117 b. Dean Faculty 0.( Natural Science, University of Sri Jayawrdanapura, Nugegoda c. Pharmacology Division, Faculty of Medicine, University of Sri Jayawrdanapura, Nugegoda. Thu, 01 Jan 2009 00:00:00 GMT http://dr.lib.sjp.ac.lk/handle/123456789/962 2009-01-01T00:00:00Z http://dr.lib.sjp.ac.lk/handle/123456789/938 Valuation of Ecosystem Services of Kala Oya River Basin: Implications for River Basin Management Gunawardena, U.A.D.P. Kala Oya Basin (KGB) is one of the largest river basins in Sri Lanka which covers an area of around 2,870 knr and expands over three provinces and four districts. The river basin covers many different types of ecosystems, valuable biodiversity resources and characterized by conflicting user interests and serious degradation issues. The present study attempts valuation of ecosystem services provided by the river basin and aims at providing recommendations for river basin management. Carbon storage and soil conservation functions, recreation, production services of homegardens, and mangrove services were valued using data collectedfrom various primary and secondary sources and using benefit transfer approach as the main valuation method. The annual value of the ecosystem services of the KGB is Rs million 23,500. The highest economic value was resulted from the carbon values (77%). The estimated value represents 1.16% ofGDP (of 2004) of the country and 7.33% of the agricultural sector GDP which highlights the significance of the potential economic gains of the basin. Development of appropriation mechanisms for the yet unrealized values and identification of conservation and monitoring priorities are the key issues identified by the present study However the study emphasizes the needfor more complex models that integrate economics, hydrology, and equity aspects which could ensure long term sustenance of the service provision of the river basin. Thu, 01 Jan 2009 00:00:00 GMT http://dr.lib.sjp.ac.lk/handle/123456789/938 2009-01-01T00:00:00Z http://dr.lib.sjp.ac.lk/handle/123456789/937 University of Sri Jayewardenepura: Towards Meeting National Aspirations Karunanayake, M.M. Thu, 01 Jan 2009 00:00:00 GMT http://dr.lib.sjp.ac.lk/handle/123456789/937 2009-01-01T00:00:00Z http://dr.lib.sjp.ac.lk/handle/123456789/936 The Impact of the Intoduction of Code Division Multiple Access Technology on the Telecommunication Industry in Sri Lanka Dharmasiri, Amal; Amarathunga, S.P.P. In this study, the impact of introduction ofCDMA Technology in the Sri Lankan telecommunication industry has been investigated. For this purpose, afield survey and a series of interviews were conducted with senior personnel 0.( the three fixed line operators and the personnel from Telecommunication Regulation Commission 0.( Sri Lanka .Based on the conceptualization model adopted the study took afour dimensional approach, covering Customer Benefits, Operator Advantages, Technological Advancement and the Regulatory Framework. Accordingly, the related elements in those dimensions were operationalized. A comprehensive questionnaire was utilized in thefield survey carried out to gather information ofthe perception ofthe customers and structured interviews were carried out with the senior industry experts to obtain their perspective ofthe other three dimensions of the study. Based on the findings of the study a marginal overall improvement in relation to the benefits received by the end user is seen. Further, the findings strongly show that CDM4 lias has brought many benefits to the operators and also it has been an advanced technology to Sri Lanka at the larger picture. In relation to the regulatory aspect of the whole process, there is further room for the improvement in order to have a smooth operation of new technological ka in future. Thu, 01 Jan 2009 00:00:00 GMT http://dr.lib.sjp.ac.lk/handle/123456789/936 2009-01-01T00:00:00Z