PMA —

Pressure-area isotherms for many polymer films lack the well-defined phase regions shown in Fig. IV-16 such films give the appearance of being rather amorphous and plastic in nature. At low pressures, non-ideal-gas behavior is approached as seen in Fig. XV-1 for polyfmethyl acrylate) (PMA). The limiting slope is given by a viiial equation... 

Pharmaceutical Manufacturers Association, In Development Biotechnology Medicines, PMA, Washington, D.C., 1991. 

Prior to the 1990s phenyhnercuric acetate was the primary bactericide and fungicide in latex and waterborne paints. Because of the increasing concerns of mercury toxicity and the potential for high consumer and occupational exposures to mercury when present in paints, the U.S. Environmental Protection Agency (EPA) induced U.S. manufacturers of PMA and other mercury compounds to withdraw their registrations for use of these substances as biocides in paints (see AIercury). Mercury compounds are used only for very limited, specific purposes, such as the use of phenyhnercuric mXx.2LX.e[55-68-5] as a bactericide in cosmetic eye preparations (see Cosmetics). 

Two statutory provisions of Tide 21 govern the introduction of new medical devices into the marketplace. Section 515 estabHshes a premarket approval appHcation (PMA) containing data and information demonstrating the safety and effectiveness of a device. Section 510(k) estabHshes a premarket notification process. Under this process, a manufacturer is required to file with the EDA, 90 days before a new device is to be marketed, a premarket notification demonstrating that the device in question is substantially equivalent to a device that was on the market before enactment of the 1976 Amendment and therefore marketable without formal EDA approval. 

Class III devices, unless they are substantially equivalent to a device already marketed without a PMA appHcation, require formal PDA approval through the PMA process before initial sale. The PMA process is comparable to the new dmg approval process (18). In both cases, safety and effectiveness data must be reviewed by PDA prior to marketing. An approved PMA appHcation acts like a private Hcense granted to the appHcant to market a particular device. Other firms seeking to market the same type of device for the same use must also have an approved PMA. 

PMA requirements differ between preamendment and post-amendment devices. Preamendment devices are those in commercial distribution before May 28, 1976 post-amendment devices are those first commercially distributed after the date. Class III post-amendment devices that are not substantially equivalent to preamendment Class III devices are considered new devices. Manufacturers of such devices are required to obtain PMA appHcation approval before marketing these. If the post-amendment device is substantially equivalent to a preamendment device and PDA has not initiated a regulatory process specifically requiring the submission of a PMA for the device category, a 510(k) submission can be made. 

FDA s medical device regulations relating to adulteration and misbranding generally apply to devices intended for use on animals. These devices, however, are exempt from the 510(k) and PMA requirements. FDA has viewed animal grooming products as being outside of its purview. 

Class III Premarket Approval. Similar to a new dmg approval, a premarket approval grants the appHcant a Hcense to market a specific weU-characterized device. These devices are subject to the requirements of Section 515 of the Eood, Dmg, and Cosmetic Act. A post-amendment device is a device put ia commercial distribution after May 28, 1976. If it is not substantially equivalent to a preamendment device it is automatically ia Class 111, and a premarket approval appHcation (PMA) is required. The appHcation must iaclude reports of preclinical and clinical studies done ia support of claims of safety and efficacy as well as any labeling claims made for the device. Once the PMA is submitted, the PDA determines whether the appHcation iacludes the required information. If the PMA is suitable for scientific review, the PDA has 180 days from the filing date to approve or deny the appHcation. Polybutester, polydioxanone, polyglyconate, and ePTPE sutures are all regulated as Class 111 devices. 

In[107] = Clear[PmB,PmA,Am,VI,VII,CIBo,CIDo,plI,pill,plIII plIV,t ]... 

Poljmrethane Foam Association (PFA), 272 Poljnjretliane Manufacturers Association (PMA), 272 POPCORN , sulfur, 108 Portland cement, 108 Portland stone, 109... 

Precious Metals Australia Ltd. (PMA), 142 Precious Metals Coiporation, 244 Precious Metals Division, 211 PREMARIN , conjugated estrogen. 111 PREMERLIN 600 CL , trifluralin, 111 PREMPHASE , conjugated estrogen, 111 PREMPRO , conjugated estrogen, 111... 

Px). In some instances, it is assumed that P = Pb, but this is not necessarily true. The quality of the interpolation depends on the ratio (Pmb Pma)/( )- In the case of N chemical shifts (spectral range —900 ppm), MB ma is larger than in the case of H (spectral range —12 ppm) or even chemical shifts (spectral range —230 ppm). However, the same variation in range occurs for P and it is by no means evident that the ratio is more favorable in the case of N NMR. 

Fig. 6-4. Minimum energy conformations of L-PA and L-phenylalanine-A -methyl-anilide (L-PMA) based on molecular mechanics calculations and UV- and NMR-spectroscopic characterizations. (From Lepisto and Sellergren [25].)...

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