Time Clock® system

A pulsed system, called Time-Clock System, has been developed. It comprises a solid dosage form coated with a hydrophobie surfactant layer to which a water-soluble polymer is attached to improve adhesion to the core [66]. The thickness of the outer layer determines the time required to disperse in an aqueous environment. Following the dispersion of the outer layer, the eore becomes available for dispersion. An advantage is that eommon pharmaceutical excipients can be used to manufacture this system. Studies performed on human volunteers showed that the lag time was not affeeted by gastrie residence time. Furthermore, the dispersion of the hydrophobic film was not influenced by the presence of intestinal digestive enzymes or by the mechanieal aetion of the stomach. 

Drug delivery induced by swelling may be achieved with swellable polymer layers based on cellulose ethers or acrylates, where with the latter pH-dependent swelling behaviour is feasible [92]. Examples are the oral Chronotopic delivery system [93], the Tune-controlled Explosion ystem (TES) [94,95] and the TIME-CLOCK -System [96-98] (Figure 6.4). 

The TIME CLOCK system for the oral dosage should enable fast and complete release of drug after a predetermined lag time [92], A tablet was made containing the drug molecule and bulking agents (lactose, polyvinlpyrrolidine, com starch, and... 

Pozzi, F., Furlani, E, Gazzaniga, A., Davis, S. S., and Wilding, I. R. (1994), The TIME CLOCK system A new oral dosage form for fast and complete of drug after a predetermined lag time, /. Controlled Release, 31, 99-108. 

A pulsed system, called the Time-Clock System, has been developed. The system comprises a solid dosage form coated with a hydrophobic surfactant layer to which a water-soluble polymer is attached to improve adhesion to the core. The thickness of the outer layer determines the time required to disperse in an aqueous environment. After the dispersion of the outer... 

Recently, it has been reported that aqueous dispersions or suspensions can be produced, in which the drug is present in enteric-coated form. The enteric-coated time clock system consists of a tablet core covered with a mixture of hydrophobic material and surfactant, which is applied as an aqueous dispersion [153]. The drug release from the core of the time clock system occurs after a pre-determined lag time. 

Real-time clocks (RTCs). Real-time systems are required to respond to events, as they occur, in a timely manner. This is especially crucial in process control systems where control actions applied at the wrong time may amplify process deviations or destabilize the processes. The nodes in the systems are interrupted periodically by the real-time clocks to maintain the ac tual elapsed times. 

Whether the boiler is fired on oil, gas or solid fuel, it may be expected that it will operate automatically. When boiler plant is not run continuously initial start-up may be manual, time clock or through an energy-management system. Manual attendance may be limited to maintenance functions dictated by the type and size of plant. Automatic controls will cover three areas ... 

With hot water units, time clock control can operate satisfactorily as automatic bypass valves built into the distribution system will help the heater to achieve its working temperature quickly. With steam boilers, it is important that the boiler reaches a reasonable working pressure before steam is allowed into the distribution system. For example, if boilers are left open to a system for an extended length of time while not firing they will quickly lose their pressure. This is not only wasteful of energy but eventually creates a problem on start-up. To... 

Therefore, where a time clock is incorporated it is recommended that the crown valve(s) be closed at the end of each working day and only opened after the boiler has reached working pressure the next time it is required. This operation can be automated by the use of motorized or similar valves. These valves may be fitted to each steam, supply line from a manifold adjacent to the boilers and, provided adequate safeguards are incorporated to protect the boilers, the on-line boiler(s) may be left open to the manifold. Alternatively, each boiler may have its own automatic motorized start-up valve. Figure 23.12 illustrates a valve suitable for either system. 

Index The index of Form 356h sets out how the extensive numbers of documents are to be referenced. A well-organized index system is important for the reviewers to search for the required information. This will expedite the review process, without the necessity for the FDA to stop the review time clock to seek clarification. 

Real-time clocking of abstraction reactions was first performed on the I-H/CO2 system for the dynamics on the ground-state PES [5] ... 

Figure 8. Package bandwidth and critical line length as a function of signal rise time or system clock speed.

In addition to the evaluation of enteric dosage forms with special systems like the Time Clock or others mentioned earlier, conventional pharmacological studies are commonly done with the final formulation to assess the desired activity profile. 

This says that the time clocks are the same in both systems. 

The HP 3052A data acquisition system consists of a 9825A calculator with a real time clock, a multichannel scanner, a high speed digital volt meter and a printer/plotter for display purposes. The system software consists of a monitoring program and an analysis program written in HPL. 

Operator interaction with the data acquisition system occurs in the manner shown in Figure 1. The user specifies a time interval, usually several seconds, over which the computer will calculate piston velocity and melt pressure. With the system described above the time interval must be on the whole second since this is the resolution of the real time clock. 

Softeners can be a microbial concern. A dark and moist column interior can provide a growth environment. The regeneration cycle which uses concentrated brine solution and a backwash cycle aids in reducing the bioburden. Softeners should be regenerated based on a time clock set for twice weekly regenerations and on a volumetric flow of water, whichever is shorter. Since the regeneration cycle removes the softener bed from operation, a dual bed system is often specified. 

The selected vibration-rotation states k of the QTS that contribute to the reaction are those having non-zero FC overlap integral. In the case where one sums over the k -states, let us replace AE by the average thermal energy available to the system, namely, k T. T is the absolute temperature and kB is the Boltzmann constant. The minimal time during which a transition is possible will be At = h / k T and we take this as the measure of time (clock) for the conversion from QTS to P1+P2. Then, let T32 be the total probability to convert the QTS into P1+P2, so that the ratio T3 2/At is the rate of conversion per QTS molecule. If [QTS] is the concentration of QTS molecules at time t, the rate measured in the laboratory will be proportional to [QTS] T3 JAt. A phenomenological rate is given by ... 

---