ORDER (No. 200/2012)
D.P.S. PARMAR, TECHNICAL MEMBER1. This is an appeal filed against the order of the Assistant Controller of Patents and Designs, Delhi dated 13th April, 2009. The patent application No. 3219/DELNP/2005 relates to âCeramic based nanoparticles for entrapping therapeutic agents for photodynamic therapy and method of using the sameâ. This appeal was heard by the Board on 2.5.2012. The learned counsel Shri Sanjeev K. Tiwari appeared for the appellants. The learned counsel for the appellant submitted that no objection in respect of novelty and inventive step was raised by the respondent in respect of claims 1 to 6 and in respect of composite claims from 7 to 11. The objections in FER were in respect of inventive step and not in respect of novelty. According to the counsel, the appellant do not respond at all in respect of claims 1 to 6, as the appellant understood that the novelty and inventiveness have been acknowledged by the respondent. In respect of objection under section 3(1), the learned counsel submitted that the appellant has made amendments by deleting claims 12 to 16.
2. The learned counsel for the appellant submitted that in respect of claims 7 to 11 (composite claims) the objection was only under the ground of lack of inventive step in view of US 2002/0127224 (US 224). However, the respondent in his impugned order rejected the composite claims as he found that the composite claims has non-construent and beyond understanding to have any enhanced effect. According to the counsel, the respondent did not recall any reasons for such observations in the impugned order.
3. The learned counsel for the appellant submitted that there was no occasion/opportunity for the appellant to explain novelty and inventive step in respect of claims 1 to 6 vis-Ã -vis US224. The learned counsel for the appellant contented in view of provisions of section 14 of the Patent Act, 1970 and considering that there was no objection for claims 1 to 6 (method claims) with regard to novelty and inventive step, these claims ought to have been granted. There cannot be further adjudication under section 15 or for the present appeal in respect of novelty and inventive step in respect of claims 1 to 6. The learned counsel submitted that hearing is granted under section 14 only when the report of the Examiner is adverse or patent application requires any amendment and not otherwise. Meaning thereby in case of favourable report of the Examiner, the examinations proceedings come to an end. It does not require further adjudication and consequently it should not be part of adjudications appeal proceedings under section 117(A) read with section 15. The impugned order is liable to be set aside on the above ground only.
4. We do not agree with the contention of the appellant that there may not be further jurisdiction under section 15. In fact section 15 emphasizes the Controller to seek amendment or refuse the patent if they are not carried out to his satisfaction. Therefore, the Controller i.e. the respondent has power to raise further objections which he found necessary before the patent is granted.
5. Section 15 clearly shows that when an objection relating to patentability is raised by the Controller the applicant must show âto the satisfactionâ of the Controller that invention is patentable. When the Controller is given the quasi-judicial duty to decide whether a patent should be granted it means he must be satisfied. If on a perusal of the application he finds that invention is not novel or there is no âinventive step, can he grant the patent only because the Examiner had not raised this objection? That would rather be a serious lapse of supervision. In such case, he should inform the patent applicant, that since he thinks there is no inventive step, the applicant must show that there is an inventive step and give him an opportunity of hearing. This is exactly what the Controller had done in this case. The applicant had the opportunity of proving novelty/inventive step at the hearing. With this argument the appellant is grasping at straws. This just like saying that if the plaint examiner numbers the suit, the Court should grant a decree. This will never be the case at least where the examiner report is being supervised by the Controller. We should also remember that several safeguards are inbuilt in the process of grant of patent. Even where the Examiner makes a search and investigation with adverse report, the Controller independently satisfies himself. There is a pre-grant or a post grant opposition stage and then revocation. Each stage is a separate hurdle independent of one another that the patent application has to cross. Therefore this being the position the technical objection raised by the applicant is not acceptable.
6. The learned counsel for the appellant however submitted that he will demonstrate novelty and inventive step even in respect of claims 1 to 6 in addition to claims 7 to 11 (composition claims). According to the appellant, only one prior art, that is, US 224 has been cited.
7. The learned counsel for the appellant submitted that only one prior art has been cited and also considered in the Impugned Order to decline grant of the patent. According to the counsel, in the FER US' 224 was cited for lack of inventive step in respect of claims 7-11 only. However, by the Impugned Order, this document was considered as destroying the inventiveness of all the claims, including claims 1-6.
US' 2002/0127224 (in short US 224) :
8. US224 is directed to use of photoluminescent nanoparticles for photodynamic therapy. In paras 3 -5 at page 1, this prior art details the technology existing in public domain. These paras identify the existing problem as application of light of a suitable wavelength to a photodynamic drug (PDT). It states that even the LEDs are not available to provide full spectrum of specific wavelengths that can be used to active PDT drugs.
9. The solution suggested in this prior art was use of Light-Emitting nanoparticles to be administered in addition to a PDT in order to activate the drug. It is taught that the Light Emitting Nanoparticles absorb light from the light source and re-emit lights at a different wavelength, which is suitable to activate the PDT drug in the vicinity of Light Emitting Nanoparticles. Thus, the role of nanoparticles is to absorb the light from a light source and re-emit the light of different wavelength to activate the PDT drug.
10. To achieve this purpose, firstly, a PDT drug is to be administered (para 92); thereupon nanoparticles are administered (para 98) and thereafter light source become active. In paras 106 - 108, the time gap between administration of PDT drug and administration of nanoparticles has been highlighted.
11. Claim 1 and claim 14 can further be referred to for proper understanding of the invention as contained in this prior art. In brief, the invention in US'224 relates to photodynamic therapy (PDT) and more specifically to illumination systems, composition and methods of using light emitting nanoparticles to activate photosensitive compounds at the target site for PDT. The composition of cited document comprises light emitting nanoparticles (quantum dots, quantum rods, nanocrystals) and quantum dots/rods composed of a semiconductor material or materials, metal(s), or metals oxide exhibiting certain band gap energy. Further there is no discussion about preparing such nanoparticles and only description about method for photodynamic therapy has been provided.
12. Figures 1, 2 and 3 (pages 62-63) if read with their descriptions (paras 59 and 61) clarify the entire invention in US'224. This illustrates the mechanism of attaching quantum dots to the antibody at the site to be treated. These further show the separate administration of PDT drug and quantum dots and the mechanism through which the entire treatment is provided by use of Light Emitting Nanoparticles (quantum dots).
13. Paras 64-67 of US'224- The teachings disclosed in these paras of the prior art are in respect of attaching quantum dots or other nanoparticles to a delivery moiety. Para 64 simply states that the nanoparticles can be attached to a delivery moiety or can be coated with silica, etc. Coating of light emitting nanoparticles with silica are especially disclosed in para 65. However, this is only in respect of coating the light emitting nanoparticles with silica and does not give any indication with respect to ceramic based nanoparticles or entrapment of PDT drug inside ceramic based nanoparticles. Para 67 teaches that light emitting nanoparticles can be linked to PDT drug under the title and heading of para 66. However, the teaching is more clarified in the following sentence as contained in para 67:
"The light-emitting nanoparticles are therefore, positioned sufficiently closely to the PDT drug to eliminate it, even in instances where tissue penetration depth of the light emitted by the nanoparticles is very small. "
14. Thus, linking to PDT drug with light-emitting nanoparticles is to be understood to bring the PDT drug as close to the light-emitting nanoparticles as possible. This is for the purpose that the PDT drug will be in a position to absorb the re-radiated light by light-emitting nanoparticles. This is entirely different concept than entrapping PDT drug inside ceramic based nanoparticles.
15. It is submitted that a delivery moiety is linked to the light-emitting nanoparticles to facilitate bringing the nanoparticle closet to the tumor cell or attaching with the new tumor cell. As discussed in the prior art and also explained in figure 3, an antibody or a drug or a protein is attached with the light-emitting nanoparticle through this delivery moiety which will facility binding of light-emitting nanoparticle with the tumor cells in the body. Thereupon or simultaneously, the PDT drug will be administered which will come into the vicinity of light- emitting nanoparticles which is bound with the tumor cells with the assistance of delivery moiety.
16. Even otherwise, chemically linking two chemical entities and entrapment of one chemical entity inside the other are two distinct and altogether different concepts and should not be confused with one and another.
17. Paras 76-77: Para 77 discloses that PDT drug may also form part of matrix or it may be absorbed into the matrix or molecule of the PDT drug may be attached to the surface of the matrix so that the dru2 and the nanoparticles are administered simultaneously. Firstly, the matrix has a reference in para 76 wherein it has been taught that light-' emitting nanoparticles can be immobilized on a matrix. This matrix is formed of a grid, fiber, fabric or other substrate that does not move when applied on or in the body. The purpose of this matrix is to keep a light-emitting nanoparticle immobilized in the body. Since the PDT drug should be in the near vicinity of the light-emitting nanoparticles, therefore, the PDT drug has to be on such matrix or should form part of such matrix. The teachings in these paras do not provide any suggestion regarding entrapment of PDT drug inside ceramic based nanoparticles. Essentially, the teachings of these paras indicate that the light-emitting nanoparticles and PDT drug remained as two different entities and both immobilized on the matrix of grid etc. This is in line of the general teachings of the prior art which teaches that light-emitting nanoparticles and the PDT drug can be administered simultaneously or at different intervals; being two different entities administered separately in the body; and the PDT drug is being activated upon receiving re-radiated light from light-emitting nanoparticles of appropriate wavelength which is different than the wavelength of the light received by the light- emitting nanoparticles from the light source.
18. The counsel for the appellant contented that on any case, method of preparation of ceramic based nanoparticle loaded with PDT drug (PDT drug entrapped inside ceramic based nanoparticle), has not, at all, been disclosed in this prior art. According to the counsel, the composition claims 7-11 of the Appellant's invention are product by process claims. Process being novel and inventive, the product (composition claims) is entitled to be held novel and inventive being limited only to the novel and inventive process.
19. The learned counsel for the appellant submitted the present Invention addresses problems arising out of hydrophobic nature of Photosensitive Drugs. It is to be noted that in the Photo Dynamic Therapy, most of the photosensitive drug used are hydrophobic in nature (poorly water-soluble). Due to the aqueous medium inside the body it is very difficult to bring the hydrophobic Photosensitive Drugs (drugs for PDT) at the target site. With the method of Appellant's invention a hydrophobic PDT drug can be entrapped inside the ceramic based nanoparticles. The objective of the invention is to provide a drug delivery system for photosensitive drug wherein the drug delivery systems protects the photosensitive drugs until the drug molecules reaches the target site. Even though the ceramic based nanoparticles entrap the PDT drug, the ceramic nanoparticles do not interfere with the activities of the PDT drug.
20. Additionally and more importantly, due to the hydrophobic nature of the PDT drug, there used to be immense difficulty in preparation of pharmaceutical formulations (lines 28-30, page 1). Therefore, it was also a challenging task to provide a solution and method for preparation of a formulation whereby PDT drug can easily be taken at the target site without compromising with its activity and at the same time minimizing the side effects.
21. According to the counsel, the method claimed in claim 1-6 provides a unique and novel method, not disclosed anywhere, prior to the priority date of the Appellant's application. He contented that the method of Claim 1 is having support at page 5 lines 6-16 and is duly explained in Example 1 at page 8 of the specification and the various steps of claim 1 should be read with Figure 2 reproduced herein below:
âIMAGEâ
22. It is to be noted that due to the hydrophobic nature of PDT drug, it is very difficult to entrap otherwise directed inside Ceramic nanoparticles or inside any other nanoparticles, Therefore, the inventor of the present invention has devised this novel method to first entrap the PDT drug by Micelles formation and then introduce nanoparticle (step b). In the step (a) Micelles are prepared to entrap the PDT drug which is highlighted by the following figure:
âIMAGE:
23. In step (b) alkoxyorganosiline is added to Micelles to form complexes of Silica and Micelles and in step (c) this complex of Silica and Micelles is subjected to alkaline hydrolysis. Towards the completion of process in step (c) one obtains Silica Nanoparticles entrapping the PDT Drug. However, at this stage, nanoparticles are still inside the Micelles and requires precipitation which is provided in step (d). The process in step (b) and (c) is described in details in example 1 and shown in figure above as under:
âIMAGEâ
24. In Step (d) a dialysis to separate the Ceramic nanoparticles entrapping the PDT drug is conducted for prolonged period of 40-50 hours. In example 1 dialysis for 40 hours is carried out. At page 27 lines 15-16 teach dialysis for a period such as 50 hours. Following extract of Figure 2 shows the desired product at the completion of step (d) or towards the end of the process of claim 1.
âIMAGEâ
25. The learned counsel for the appellant submitted that there is no hint/suggestion, at all, in respect of any process whereby ceramic based nanoparticles entraps PDT drug in US'224 much less the above process of Appellant's invention. The various steps of the independent process claim are unique, novel and inventive. In fact, entrapping of the PDT drug by ceramic based nanoparticles has not at all been taught in US '224. Linking of drug and light-emitting nanoparticles or immobilization of PDT drug on a matrix of grid/fiber/fabric is totally different and distinct from the concept of entrapment of drug inside ceramic based nanoparticles. The teachings in US'224 cannot by any stretch of imagination construed to even remotely suggest the entrapment of a drug inside ceramic based nanoparticles much less any suggestion regarding the novel method of the invention as described above.
26. The learned counsel therefore contented that the composition prepared out of the novel and inventive method of claims 1 to 6 as claimed in claims 7 to 11 are composition/product by process claim. The process being novel and inventive, the composition claims are entitled to be held as novel and inventive.
27. The learned counsel submitted that the main object of this invention is to provide a drug delivery system for photosensitive drug wherein the drug delivery systems protects the photosensitive drugs until the drug molecules reaches the target site. The drug delivery system used in the invention is a ceramic nanoparticle which entraps the drug but does not interfere with the photosensitive drug. The drug used is capable of generating singlet oxygen even though it is entrapped and this singlet oxygen is able to permeate out of silica matrix. Thus, the particle matrix does not interfere with the visible absorption spectra of the entrapped drug, the quenching of fluorescence of the drug was largely prevented in an aqueous media. Example 6 provides a comparative study in respect of the activities of PDT drug, inter alia, in the entrapped or un-entrapped form. The results of the study are highlighted in lines 3-11 at page 14 and are shown in figure 8 of the specification by way of bar chart.
28. According to the counsel, the specification provides various examples detailing the method and the advantages of the invention and utility/use thereof alongwith various drawings:
(a) Example 1 (page 8) describes completely the preparation of drug loaded silica nanoparticle.
(b) Example 2 establishes that the emission characteristics of the entrapped drug are same as the un-entrapped drug.
(c) Example 3 and 4 demonstrate generation of singlet oxygen by entrapped drug.
(d) Example 5 shows silica nanoparticle entrapping the drug can be taken by cells.
(e) Example 6 demonstrates that silica nanoparticles of the present invention can be used for photodynamic therapy. It shows the advantages of use of novel composition prepared by novel method of the invention.
(f) Example 7 is the illustration of in-vivo testing in mice.
29. According to the learned counsel, differences between US 224 and the invention subject matter of Appeal are as follows:-
a. In the Appellant's invention photosensitive drugs are entrapped within ceramic based nanoparticles; whereas US '224 envisages a composition comprising two different entities - the light-emitting nanoparticle and the photosensitive drug;
b. US '224 is only concerned with the use of photodynamic therapy and not the preparation of nanoparticles; whereas the Appellant has a conceptually different invention - Appellant has fabricated a new nanoparticle (ceramic based) and a process for preparation of the entrapped PDT drug inside nanoparticle;
c. Independent claim 1 claims preparation of ceramic nanoparticle loaded with one or more photosensitive drugs. The US' 224 does not throw any light in respect of preparation of nanoparticles much less PDT drug entrapped inside nanoparticles. US'224 simply uses Light Emitting Nanoparticles.
d. In fact, there is no guidance in US'224 regarding entrapping the PDT drug inside the ceramic based nanoparticles.
e. The nanoparticles used in US'224 is for absorption of light of one wavelength and emission of light at another wavelength to activate PDT drug at site. Whereas, in the Appellant's invention, role of nanoparticles, is to keep the PDT drug inside, carry it to the target site; no interference with the activity of PDT drug and has no role in generating light of different wavelength. The purpose and objective in the two inventions are totally distinct and different.
f. Additionally, the nanoparticle as invented by the Appellant is not a light emitting particle; it is a wholly ceramic based particle; whereas the particle of US '224 is made of semiconductor material. US '224 also recommends use of quantum dots which are made of cadmium which is toxic to healthy human cells; the aim of the photodynamic treatment is to kill cancerous cells without damaging surrounding healthy cells; use of cadmium based quantum dots causes toxicity to surrounding cells;
g. Nanoparticles and quantum dots of US '224 being fabricated to have absorption spectrum of shorter wavelength and the same constantly shifts with the change in particle size; whereas the Appellant's ceramic based nanoparticles are capable of absorbing spectrum of higher wavelength and the spectrum hardly shifts - in that the particles are stable and therefore far more useful for photodynamic therapy;
h. As per US '224 a nanoparticle as well as drug are to be administered separately whereas the Appellant's invented single delivery system comprising PDT drug entrapped inside ceramic based nanoparticle;
i. The nanoparticle system designed by the Appellant is completely and fully ceramic based whereas US '224 employs light emitting nanoparticles made of different material;
j. The invented ceramic nanoparticles are highly stable and do not release any encapsulated bio-molecules even at extreme conditions of pH and temperature.
30. The learned counsel for the appellant submitted that the inventive step in respect of claimed invention is explained below:-
a. Appellant's invention addresses the problem arising out of hydrophobic nature of photosensitizing drugs used In PDT. It provides a solution whereby the hydrophobic PDT drug can easily be carried on to the target site in spite of aqueous medium present in the body. The novel method of the Appellant's invention provides a method whereby a PDT drug can be entrapped inside the ceramic based nanoparticles which can be administered to a patient.
b. In fact, the concept of entrapping the PDT drug inside the ceramic based nanoparticles in itself is novel and unique. There is no prior art suggesting even such concept much less any process/method or disclosing any such composition. US'224 certainly does not throw any light on the method and composition of the Appellant's invention.
c. In the Appellant's invention ceramic based nanoparticles loaded with PDT drug as a singular entity are delivered/administered as opposed to delivery of two different entities (light-emitting nanoparticles and PDT drug) in US'224;
d. The nanoparticles of the invention as claimed are so designed that it protects the photosensitive drug until the drug molecule reaches the target site; the ceramic nanoparticles entrap the drug without interfering with the visible absorption spectra of the entrapped PDT drug or the activity of the entrapped drug;
e. The photosensitive drug is generates singlet oxygen and produces the required fluorescence necessary for photodynamic treatment from within the ceramic entrapment; the singlet oxygen thus generated permeates out of the silica matrix and upon irradiation kills target tumor cells.
f. The invented ceramic nanoparticles are highly stable and do not release any encapsulated bio-molecules even at extreme conditions of pH and temperature.
g. The nanoparticle system designed by the Appellant is completely and fully ceramic based whereas the prior art employs light emitting nanoparticles made of different material;
h. US '224 does not throw any light, at all on the preparation of nanoparticles as invented by the Appellant. Needless to state, no prior art other than the said US '224 has been put against the invention of the Appellant. Ingenuity and novelty of the invention lies, inter alia, in designing aforesaid novel ceramic nanoparticles, preparing the nanoparticles with photosensitive drug is entrapped inside such ceramic nanoparticles.
31. The learned counsel further contented that the Impugned Order rejected the patent application only on the ground of lack of inventive step, no other document apart from US'224 has been cited. There is no discussion regarding the gap existing between US'224 and Appellant's invention and as to how the person skilled will bridge that gap. In the absence of any such discussion and reasons, the Impugned Order does not sustain. It is therefore, prayed that the Impugned Order be set aside, the Appeal is allowed and the Indian Patent Application No.3219/DELNP/2005 be granted.
32. The patent application as originally filed with 21 claims was granted wherein claims were reduced to 14. Clams 1 to 6 were for method of preparing ceramic nanoparticles loaded with drugs and claims 7 to 13 being composition claims. Claim 14 was a omnivorous claim covering method and composition as substantial being described. Claims 1 to 7 are reproduced below:-
â1. A method of preparing ceramic nanoparticles loaded with one or more photosensitive drugs comprising the steps of:
a) preparing micelles entrapping the photosensitive drugs;
b) adding alkoxyorganosilane to the micelles to form complexes of silica and the micelles;
c) subjecting the complexes of silica and micelles to alkaline hydrolysis to precipitate silica nanoparticles in which the photosensitive drug, molecules are entrapped; and
d) isolating the precipitated nanoparticles by dialysis
2. The method as claimed in claim I, wherein step (b) alkoxyorganosilane is triethoxyvinylsilane.
3. The method as claimed in claim 1, wherein the micelles comprises AOT and 1-butanol.
4. The method as claimed in claim 1, wherein step (c) alkaline hydrolysis is carried out by ammonia.
5. The method as claimed in claim 1, wherein the alkaline hydrolysis is carried out by ammonium compound.
6. The method as claimed in claim 1, wherein step (c) the photosensitive drug, is 2-devinyl-2-(1-hexyloxyethyl) pyropheophorbide.
7. A composition comprising ceramic nanoparticles in which one or more photosensitive drugs are entrapped by a method comprising; the steps of:
a) preparing micelles entrapping the photosensitive drugs;
b) adding alkoxyorganosilane to the micelles to form complexes of silica and the micelles ;
c) subjecting the complexes of silica and micelles to alkaline hydrolysis to precipitate silica nanoparticles in which the photosensitive drug, molecules are entrapped; and
d) isolating the precipitated nanoparticles by dialysis.â
33. The present application discloses method of preparing ceramic nanoparticles loaded with one or more therapeutic agents used for photodynamic therapy (PDT) in which one or more therapeutic agents are entrapped comprising steps by claims 1 (a) to (d). It also claimed composition comprised of ceramic based nanoparticles in which one or more therapeutic agents are entrapped by method disclosed in claim 7.
34. The specification discloses in one embodiment that this invention provides a method for the synthesis of photosensitizer dye/drug doped silica-based nanoparticles (diameter ~30 mm), by controlled alkaline hydrolysis of a ceramic material (such as triethoxyvinylsilane (VTES)) in micellar media.
35. In an other embodiment, the photosensitive drug/dye used was 2-devinyl-2-(1-hexyloxyethyl) pyropheophorbide (HPPH), an effective photosensitizer which is in Phase I/II clinical trials at Roswell Park Cancer Institute, Buffalo, NY, USA [32,33].
36. Advantageously, the particle matrix does not interfere with the visible absorption spectra of the entrapped photosensitizing drug, but quenching of fluorescence of the drug was found to be largely prevented in aqueous media. Further, Singlet oxygen detection experiments revealed that the entrapped photosensitizer is able to interact with the surrounding molecular oxygen and the singlet oxygen generated is able to permeate out of the silica matrix. Thus, such doped particles are actively taken up by tumor cells and light irradiation of suitable wavelength resulted in irreversible destruction of such impregnated cells. Accordingly, the ceramic-based nanoparticles of the present invention can be used as carriers for photodynamic therapy drugs. The question before us is whether claimed invention is obvious in view of teachings of US224.
37. The respondent relied on US224 and we find this prior art does not teach or formally suggest a method of synthesizing ceramic based nanoparticles entrapped with photosensitive drugs where the method involve steps restricted in claim 1. Further the prior art does not disclose the photo sensitive drug/dye targeted by the invention i.e. 2-devinyl-2-(1-hexyloxyethyl) pyropheophorbide (HPPH). In other words, hydrated ceramic based nanoparticles entrapped with HPPH prepared by the method cited in the claim 1 is not disclosed. The respondent has cited para 0010, 0035 and para 0064 of US224 patent to substantiate lack of inventiveness. The respondent appears to have drawn a conclusion based on US479 disclosing coating of nanoparticles with e.g. thin coating (0.5 to 2nm) of silica glass and linking the nanoparticle to delivery moiety. The respondent could not clearly find that the prior art teaches the invention or formally suggest the method as claimed by the appellants. That is why the respondent while analyzing the specification, cited document and submissions made by the Agent for appellant has concluded that âhe do agree that the above methods steps are not specifically described in the cited document but understand that given the knowledge of cited document and prior arts existing before the priority date of this impugned application a person skilled in the art shall arrive at the invention disclosed are claimed in amended claims thereof in this patent application No. 3219/DELNP/2005.â The respondent further stated that âhe do not agree to any specific advantage out of the method described in absence of comparative data.â
38. We differ from findings of the respondent in view of
1. Light emitting nanoparticles are used in US224 as compared to ceramic based nanoparticles where silica particles are organically modified silicate (ORMOSIL);
2. the prior art does not suggest any method as claimed in claim 1;
3. ORMOSIL nanoparticles can be loaded with both hydrophilic as well as by hydrophobic drugs;
4. US224 involves administration of (0098) one or more or mixture of light emitting nanoparticles (0098) and drugs separately (0092). Light emitting nanoparticles delivered are after 1 hr. and 72 hrs when PTD drug is administered (0106); whereas in the present invention, drug is already entrapped in the ceramic nanoparticles and no light emitting nanoparticles is required to illuminate it.
5. finally according to the invention in question since the nanoparticles entrapped PDT drug is covered with silica, it can be used directly for irradiation.
39. We find his analysis lacking in so far as to arrive at the conclusion relating to inventive steps is concerned. The respondents reasoning failed to show that this invention was obvious. We are therefore inclined to set aside his order but we are limiting it to claims 1-6 only for the reasons in view of our finding given in succeeding paragraphs.
40. Now we consider the claims relating to product by process. So far as claims 7 to 13 are concerned, they are in fact product by process claims, which define a product in terms of the method (special step) used to manufacture the same. Such product by process claim is limited to the situation where the product could not be defined or distinguished from the prior art except by reference to the claimed process by which the product is made. In these cases, the resulting product exhibits certain enhanced properties as compared to the prior art product having same nominal composition but applicant is unable to define or identify such difference in the structure of the claimed composition and prior art composition.
We find an interesting case in this regard where Judge Newman in the decision of In re Thorpe, 227 USPQ 964, 966 (Fed. Cir. 1985) has held that :
âProduct-by-process claims are not specifically discussed in the patent statute. The practice and governing law have developed in response to the need to enable an Applicant to claim an otherwise patentable product that resists definition by other than the process by which it is made. For this reason, even though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself.â
Further in Atlantic Thermoplastics Corp. v. Faytex Corp., 23 USPQ 2nd 1481 (Fed. Cir. 1992),Judge Rader characterized product-by-process claims as follows:
 âIn sum, the PTO and the CCPA acknowledged product-by-process claims as an exception to the general rule requiring claims to define products in terms of structural characteristics. This exception, however, permitted an applicant to claim a product in process terms, not to acquire exclusive rights to a product already in the prior art. Though using only process terms, a product-by-process applicant sought rights to a product, not a process. Therefore, the applicant had to show that no prior art product anticipated or rendered obvious the product defined in process terms.â
41. In view of above judgment, we also feel that product-by-process claims must also define a novel and unobvious product, and that its patentability cannot depend on the novelty and unobviousness of the process limitations alone. Therefore, the patentability of a product by process claim is based on the product itself if it does not depend on the method of production. In other words, if the product-by-process claim is the same as or obvious from a prior product, the claim is un-patentable even if the prior art product was made by a different process. Accordingly the product by process claim must define a novel and un-obvious product and the patentability in such claim cannot depend on the novelty and un-obviousness of the process limitation alone.
42. The case we are dealing with is not of the kind which qualify for grant of product by process claim as the applicant himself admits in Example 2 that the emission characteristics of the entrapped drug is same as the un-entrapped drug. It is also admitted that such hydrated ceramic based nanoparticles of silica, aluminum, titanium etc, are also known for their compatibility in biological system (see reference 24, 25, 26 page 2 ).
43. In the present case we are dealing with PDT drug which is same but only the carriers are different. Difference between prior art composition and claimed composition is in the use of non-bio-gradable carrier. In the prior art, the carrier is polyacrylamide non-degradable nanoparticles but in the claimed invention the carrier is ceramic based, which is also non-bio-degradable.
44. The above findings show that the appellant had not put forth any evidence showing that the product based on process claim was novel and unobvious. We agree with the respondents finding that âthe composition claimed has known constituents and beyond understanding to have any enhanced effectâ. Therefore, we are inclined to disallow claims 7-13.
45. In view of the above findings, we therefore allow the claims relating to method claims with amendments. The order of the Assistant Controller to that extent is set aside and we direct the respondent to allow the grant the patent with following amended claims.
â1. A method of preparing ceramic nanoparticles loaded with a photosensitive drugs comprising the steps of:
a) preparing micelles entrapping the photosensitive drugs ,wherein the photosensitive drug is the photosensitive drug, is 2-devinyl-2-(1-hexyloxyethyl) pyropheophorbide ;
b) adding alkoxyorganosilane to the micelles to form complexes of silica and the micelles;
c) subjecting the complexes of silica and micelles to alkaline hydrolysis to precipitate silica nanoparticles in which the photosensitive drug, molecules are entrapped; and
d) isolating the precipitated nanoparticles after dialysis
2. The method as claimed in claim I, wherein step (b) alkoxyorganosilane is triethoxyvinylsilane.
3. The method as claimed in claim 1, wherein the micelles comprises sodium bis (2-ethylhexyl) sulfosuccinate (AOT) and 1-butanol.
4. The method as claimed in claim 1, wherein step (c) alkaline hydrolysis is carried out by ammonia.
5. The method as claimed in claim 1, wherein the alkaline hydrolysis is carried out by ammonium compound.
46. The patent may proceed for grant accordingly.