A patent application of F. Hoffmann-La Roche AG, for “POWDER FORMULATION FOR VALAGANCICLOVIR” has been refused by the Indian Patent office (IPO).

The invention, as disclosed by the applicant aimed to improve the stability profile and the manufacturability of the powder dosage form and the formulation procedure was changed from a dry mix granulation to a wet mix granulation. Their product claim is reiterated as follows:

“1. A solid pharmaceutical dosage form for oral administration, after being constituted in water, comprising:

• valganciclovir hydrochloride in an amount from 10% to 90%, by weight of the total composition; and

• fumaric acid, an amount to lower the pH of the constituted solution of valganciclovir hydrochloride to a pH of about 3.8 or below, to stabilize the valganciclovir hydrochloride in water, wherein the dosage form has following composition:

Equivalent to 50mg of Valganciclovir (as free base) on a dry basis.”

The use of fumaric acid had not been previously reported, and the applicant claimed technical advancement in the same to obtain a patent. It was also alleged by the applicant that the stability of the powder product using fumaric acid is better that product obtained using citric acid. The applicant also produced a comparison table to highlight the assay values obtained using both the acids individually.

The Deputy Controller pointed towards  teaching in the prior art that composition of valaganciclovir is stable below pH 3.8. Further, the use of an organic acid (like citric acid) having pH less than 3.8 has also been reported in prior art and the pH value of fumaric acid is 3.19.The Deputy Controller held that fumaric acid is nothing but merely an alternate organic acid available within the preferred pH range.

The Deputy controller also observed in the comparison table so produced by the Applicant, that the assay values were close, and also well within the acceptable range.

Accordingly, it was held by the Deputy Controller that there is no technical advancement achieved from the applicant’s invention and it does not have any “inventive step”. For the same reason the grant of patent was refused under Section 15 of the Patents Act.