ABSTRACT
Current literature indicates that an in vitro release test (IVRT) can serve as a research tool during the course of developing topical formulations. The purpose of this study was therefore to investigate the ability of an IVRT to select the topical semisolid formulations with the most rapid release rate of the model drug ketoprofen from two closely related hydrogels in a simulated product development process. Two glycols with distinct differences in their physical-chemical properties, Transcutol P (ethoxydiglycol) and propylene glycol, were incorporated into Carbopol 980 and Poloxamer 407 formulations. The release rate of ketoprofen was determined utilizing different receptor media and conditions, i.e., phosphate buffer pH 7.4, isopropyl myristate (IPM), and a combination of an IPM soaked membrane and phosphate buffer (pH 7.4) as receptor fluid. The results indicated that the conditions chosen could affect greatly the conclusions concerning the formulations. The only observable trend was that Transcutol P-containing formulations tended to permit a faster ketoprofen release than propylene glycol-containing formulations when utilizing IPM as a receptor component. This was attributed to the mutual miscibility of Transcutol P in IPM. It can be concluded that, for the purpose of formulation screening in the early phases of product development, an IVRT will only be useful for predicting the amount of drug available for absorption if the receptor medium has properties that closely mimic human skin. These results illustrate the importance of selecting suitable receptor components and indicate that it may be necessary to consider alternatives to the commonly used synthetic membranes.
Subject(s)
Delayed-Action Preparations/pharmacokinetics , Drug Evaluation, Preclinical/methods , Ketoprofen/pharmacokinetics , Anti-Inflammatory Agents, Non-Steroidal/chemistry , Anti-Inflammatory Agents, Non-Steroidal/pharmacokinetics , Chemistry, Pharmaceutical , Delayed-Action Preparations/chemistry , Diffusion , Ethylene Glycols/chemistry , Ethylene Glycols/pharmacokinetics , Excipients/chemistry , Excipients/pharmacokinetics , Hydrogels/chemistry , Hydrogels/pharmacokinetics , Ketoprofen/chemistry , Poloxamer/chemistry , Poloxamer/pharmacokinetics , Propylene Glycol/chemistry , Propylene Glycol/pharmacokinetics , Protease Inhibitors/chemistry , Protease Inhibitors/pharmacokinetics , SolubilityABSTRACT
The purpose of this pilot study was to determine if clinically acceptable complete denture prostheses can be consistently fabricated with a new injection system. In the first part of this investigation, 14 patients requiring complete denture fabrication had one prosthesis made with the new injection system and one made with the compression-pack technique. Polish, porosity, and esthetics were evaluated by one of three investigators at the placement visit. The percentage of the intaglio surface in contact with the mucosa before adjustment was also measured. One week after placement, the patients were questioned regarding the prostheses' stability, the presence of any undesirable taste, and overall satisfaction. The second portion of the study involved materials property testing of flexural strength and Izod toughness of conventionally packed and injection-packed specimens processed by the fast cycle or the long cycle. In every case, acceptable results were obtained for the resin's polishability, its lack of porosity, esthetics, stability, lack of unpleasant taste, and overall patient satisfaction with the prostheses. No difference in clinical adaptation was observed. These results indicated that no clinical difference was detectable between the conventionally packed and injection-packed denture bases by the investigators or patients in this study. Physical property testing indicates that the differences between groups may be more affected by the polymerization cycle used than the way that the resin was placed in the mold space.
Subject(s)
Denture Bases , Denture Design , Acrylic Resins , Dental Polishing , Denture, Complete , Hardness , Humans , Patient Satisfaction , Pilot Projects , PorosityABSTRACT
This article addresses the dental amalgam debate from two aspects. The first is a review of the current status regarding the appropriate treatment planning of direct restorations. The second is a discussion of the safety of amalgam and the mercury toxicity concerns. Dental research continues to support the use of amalgam while the search continues for the "ideal" restorative material.
Subject(s)
Dental Amalgam , Dental Amalgam/adverse effects , Dental Restoration, Permanent , Humans , Mercury/toxicity , Patient Care Planning , Patient Education as Topic , SafetyABSTRACT
Campylobacter jejuni is the most common enteric pathogen isolated from university and college students in the United States. During the fall and winter quarters of the 1983-1984 academic year, the authors conducted a case-control study at the University of Georgia, Athens, Georgia, to identify risk factors for C. jejuni enteritis. Students with diarrhea whose cultures yielded C. jejuni were compared with controls matched by age, sex, and residence. A total of 45 case-control pairs were interviewed about exposures during the week before the case's onset of illness. The infections occurred sporadically and were caused by a wide variety of C. jejuni serotypes. Three risk factors were identified: eating fully cooked chicken, eating chicken reported to be raw or undercooked, and contact with a cat or kitten. No case reported drinking raw milk. No significant association was found between illness and the places where chicken meals were prepared or the specific manner in which chicken was cooked. Chicken may be the principal vehicle of transmission for sporadic Campylobacter enteritis among college students.