“To produce a mighty book, you must choose a mighty theme. No great and enduring volume can ever be written on the flea, though many there be who have tried it.”
"In my judgment it is not sufficient to prove common general knowledge that a particular disclosure is made in an article, or series of articles, in a scientific journal, no matter how wide the circulation of that journal may be, in the absence of any evidence that the disclosure is accepted generally by those who are engaged in the art to which the disclosure relates. A piece of particular knowledge as disclosed in a scientific paper does not become common general knowledge merely because it is widely read, and still less because it is widely circulated. Such a piece of knowledge only becomes general knowledge when it is generally known and accepted without question by the bulk of those who are engaged in the particular art; in other words, when it becomes part of their common stock of knowledge relating to the art."
“If dermal delivery is required the drug can be designed to remain in the stratum corneum layer, rather than pass into the viable epidermis, and can spread laterally through the stratum corneum. Whereas for transdermal delivery rapid diffusion across the skin is desired, so a low molecular volume is preferable, for dermal delivery the molecular volume tends not to be a significant concern. A compound for dermal delivery, though, is preferably hydrophobic with a logP of 4 to 6. These factors, and their theoretical and experimental analysis had been extensively reported by September 1995. They would certainly have been known to those working in the technical field of dermal or transdermal drug delivery and I would also have expected most formulators to have known them as at that date. They were taught on undergraduate courses at Cardiff University and also, I believe, at other universities.”
“Here, a highly concentrated formulation of the active agent is deposited along the animal’s back. The insecticide is then able to spread through the fleece, most likely by diffusion within the emulsion layer on the wool and skin surface. The concentration of active agents, therefore, decreases with distance from the application site (40; Johnson unpublished data)…. By using autoradiography, Jenkinson et al. found that cypermethrin, applied as a pour-on formulation, spread radially across the skin within the stratum corneum at a rate which exceeded 11 cm/hr. The spread was accompanied by some dermal infiltration which was most marked at the site of application.”
“one possible route of transfer is by the intercellular channels of the stratum corneum of the epidermis which are permeated with a mixture , probably an emulsion of sweat and sebum.”
“It is highly probable, although still not certain, that this effect is a result of lateral movement of the intercellular sweat/sebum emulsion. If, however, this proves to be the case, then the rates of movement of different products will be influenced by their capacity to mix with the emulsion and by the compatibility of the medium in which they are applied. Full understanding of the manner in which substances traverse the stratum corneum would appear therefore to depend on more detailed knowledge concerning the nature of the intercellular emulsion in different species. However, identification of the route of travel provides a basis for more detailed scrutiny of the rate and extent of travel of cypermethrin and of the ability of other substances … to move within the stratum corneum.”
“It remains open to speculation whether dermal spreading of pour-on formulations is additionally mediated by dermal gland secretions (Pitman & Rostas, 1981) or possibly by movement in the intracellular space of the stratum corneum (McEwan Jenkinson et al., 1986).”
“Dr Walters’ approach is based on the premise that it would be possible to target the stratum corneum with fipronil, such that lateral spreading could be achieved across the whole of the animal in the stratum corneum layer ... As I shall explain below, there was no general understanding of, nor accepted scientific basis for, this approach. It was not one that I was aware of, nor was it an approach that was taught or understood. I do not consider that the skilled person would have thought that fipronil (or any active) could be effectively administered non-systemically via lateral spreading in the stratum corneum.”
“The compositions according to the invention, intended for pets, especially dogs and cats, are generally applied by depositing on the skin (in English “spot on” or “pour on”); it is generally a question of localised application on a surface area of less than 10 sq. cm., especially between 5 and 10 sq. cm, in particular at two points and preferably located between the animal's shoulders. After being put on, the composition spreads, particularly over the animal's whole body, and then dries, without crystallisation and without changing the appearance (in particular there is no whitish deposit or dusty appearance), or the feel of the animal's coat.”
“The compositions according to the invention intended for pets, preferably cats and dogs, are generally applied by being deposited onto the skin ("spot-on" or "pour-on" application); this is generally a localized application over a surface area of less than 10 cm 2, especially of between 5 and 10 cm 2, preferably at two points and preferably localized between the animal's shoulders. Once deposited, the composition diffuses, preferably over the animal’s entire body, and then dries without crystallizing or modifying the appearance (preferably absence of any whitish deposit or dusty appearance) or the feel of the fur.”
“The compositions for spot-on application according to the invention are usually prepared by simple mixing of the constituents as defined earlier; advantageously, to begin with, the active material is mixed in the main solvent and the other ingredients or adjuvants are then added.”
“The discovery that the compound (A), such as fipronil, dissolves in the sebum so as to cover the entire animal and becomes concentrated in the sebaceous glands, from which it is gradually released over a very long period, is a plausible explanation of this long-lasting efficacy for these compositions, and could perhaps also explain the long-lasting action of the associated compound (B).”
“The question of obviousness must be considered on the facts of each case. The court must consider the weight to be attached to any particular factor in the light of all the relevant circumstances. These may include such matters as the motive to find a solution to the problem the patent addresses, the number and extent of the possible avenues of research, the effort involved in pursuing them and the expectation of success.”
“Mere possible inclusion of something within a research programme on the basis you will find out more and something might turn up is not enough. If it were otherwise there would be few inventions which were patentable. The only research which would be worthwhile (because of the prospect of protection) would be in areas totally devoid of prospect. The “obvious to try” test really only works where it is more-or-less self evident that what is being tested ought to work.”
“In the end the question is simply "was the invention obvious?" This involves taking into account a number of factors, for instance the attributes and cgk of the skilled man, the difference between what is claimed and the prior art, whether there is a motive provided or hinted by the prior art and so on. Some factors are more important than others. Sometimes commercial success can demonstrate that an idea was a good one. In others "obvious to try" may come into the assessment. But such a formula cannot itself necessarily provide the answer. Of particular importance is of course the nature of the invention itself.”
“In the Court of Appeal, Jacob LJ dealt comprehensively with the question of when an invention could be considered obvious on the ground that it was obvious to try. He correctly summarised the authorities, starting with the judgment of Diplock LJ in Johns−Manville Corporation's Patent[1967] RPC 479 , by saying that the notion of something being obvious to try was useful only in a case in which there was a fair expectation of success. How much of an expectation would be needed depended upon the particular facts of the case.”
“You would just go through the fairly logical steps and rational judgments on the properties you wanted. You would use certain compounds if you wanted it to permeate the skin, and others if you did not.”
“Insofar as the Patent is not invalid [for lack of inventive step] the Claimant will say that the disclosure is no more enabling than that of the prior art cited above and accordingly the specification of the Patent does not disclose the invention clearly enough or completely enough for it to be performed by a person skilled in the art.”