Process validation may be defined as a systematic approach to identi fyi ng, measunng,rnevaluating, documenting and re-evaluating a series of critical steps III the manufacturingrnprocess that require control to ensure a reproducible final product. The approach is based onrnthe principle that "quality is not tested into a product but rather is built into a product".rnIt is with this principle in mind that this work has been designed and conducted. Thernvalidation study was limited to the tablet manufacturing process in the EthiopianrnPharmaceuticals Manufacturing Factory (EPHARM). Three tablet products were selected,rnnamely, Chloroquine phosphate 250 mg, Paracetamol 500 mg and Frusemide 40 mg for thernstudy. Chloroquine phosphate, is a highly water-soluble salt with little or no compressibilityrnproblems. Paracetamol is moderately soluble in water with a high tendency to capping.rnFrusemide is practically insoluble in water which may pose problems in drug release.rnIn this study, the manufacturing facility and equipment, the raw material acquisition andrntesting procedures, the tablet manufacturing process, and the in-process control proceduresrnwere evaluated. Samples of the in-process materials and the fini shed products were taken andrntested for compliance with quality specifications.rnThe results of the study suggest that the proportion of fines in granulations of some of thernproducts was excessive (chloroquine phosphate). Measurements of angle of repose indicaternthat the granulation bulk density, flow and surface characteristics were generally good. One-way analysis of variance (ANOY A) revealed that there was significant vari ation 111 therngranulation moisture content of all of the products tested. Paracetamol tablets lacked the shinyrnsmooth appearance expected of plain, compressed tablets. High hardness variation has beenrnobserved in some products (paracetamol, frusemide) but thickness was within thernspecification in all cases. Two batches of paracetamol capped and, hence, failed friability testrnspecifications. The tablets complied with the official weight variation and content uniformityrnspecifications, but the range need to be narrowed through the use of internal specifications.rnTablets of all of the products tested disintegrated within the specified time. Dissolution raternwas within the official requirements in all cases. Complete in vitro drug release (90% or morernof label claim) was observed in all cases, but the optimum goal of achieving 90% drug releasernbelow 30 min was not attained particularly with frusemide and in some batches ofrnparacetamol.rnStandard operating procedure (SOP) was not strictly followed during some of the unitrnoperations. The document (batch manufacturing record) was lacking the necessary detailsrnrequired of such a document. For example, mixing time and mixing intensity in mixers,rndrying time and temperature in dryers, machine speed, compression force etc. in tablet pressesrnwere not clearly stated. No in-process control activity was observed at the granulation stagernand there were no quality specifications available for the granules. Machine cleaning andrnmaintenance procedure and documentation was lacking. Personnel training was inadequate.rnGenerally the GMP requirements in the area of facility and equipment, personnel, processrnvalidation, documentation, etc. are not fulfilled.