Patent systems rarely change through abrupt doctrinal breaks. More often, they evolve through practice: by repeated examination patterns, shifting evidentiary expectations, and reasoning styles that harden into habit. This is particularly true in pharmaceutical and biotechnology patent prosecution before the Mexican Institute of Industrial Property (Instituto Mexicano de la Propiedad Industrial, or IMPI).
Although the statutory framework in Mexico had until recently remained largely stable, the practical threshold for patentability has been steadily – and quietly – increasing.
These elements reflect a gradual tightening of standards that draws selectively from US and European practice, without fully importing the analytical constraints that accompany those doctrines in their jurisdictions of origin.
Obviousness as an expansive and unstructured inquiry
At the centre of current Mexican pharma–biotech practice lies an increasingly expansive approach to inventive step. While Mexican law formally requires an assessment based on the perspective of the person skilled in the art, examination practice frequently treats the existence of a general technical motivation or development pathway as sufficient to negate inventive step.
Once the prior art identifies a therapeutic target, a known active ingredient, a chemical scaffold, or a general formulation strategy, examiners in Mexico are keener to conclude that arriving at the claimed subject matter would have required no inventive effort. The skilled person is implicitly assumed to move confidently from a general disclosure to a specific solution, even in fields characterised by high levels of uncertainty and experimental failure. In pharma and biotech innovation, however, development pathways are rarely linear, and the identification of a viable embodiment depends on unpredictable interactions between multiple variables.
Comparatively, US practice embraces flexible obviousness reasoning but still emphasises the need for a rational underpinning and a demonstrable link between the prior art and the claimed invention. European practice, in turn, relies on a structured problem–solution approach that explicitly asks whether the prior art would have led the skilled person to the claimed solution with a reasonable expectation of success.
Formulations, incremental innovation, and the language of routine
This expansive view of inventive step directly shapes how pharmaceutical developments are assessed in Mexico. Historically, such inventions have been treated with scepticism, regularly dismissed as mere refinement of known active ingredients. In many office actions, excipients, dose ranges, salt forms, polymorphs, and release profiles are frequently characterised as routine choices lying squarely within the ordinary competence of the skilled person. In practice, however, these elements are decisive for therapeutic success.
Improvements in stability, bioavailability, patient compliance, or dosing frequency emerge from extended experimentation rather than predictable selection. Both US and European practice increasingly recognise that such developments may involve inventive step where the claimed solution produces a non-obvious technical effect.
Mexican practice reflects a persistent tension. On the one hand, examination reports continue to rely on the language of routine optimisation to reject claims directed to formulations or dosage regimens. On the other, examiners increasingly demand detailed experimental support to substantiate the alleged technical effects of those same inventions.
Evidence, experimental support, and claim scope
The growing emphasis on experimental evidence is one of the most consequential features of current Mexican pharma–biotech practice. Applicants are frequently required to provide extensive data to support inventive step, including comparative studies, stability data, and, in some cases, in vivo results. At the same time, that evidence is used to narrow the effective scope of the claims. Office actions may suggest that the claimed invention achieves its asserted technical effect only under the specific conditions assessed, effectively reading limitations from the examples into the claims.
For practitioners, this creates a practical dilemma. Robust experimental support is increasingly necessary to overcome objections, yet providing such support may confine the invention to the precise embodiments disclosed. Experimental data thus functions not only as proof but also as an implicit boundary-setting mechanism for claim interpretation.
Against this backdrop, the growing use of negative claim features in Mexican chemical, pharma, and biotech patents becomes more comprehensible. Exclusions, disclaimers, and ‘free from’ language are frequently introduced to distance claims from prior art identified during prosecution. While negative limitations are well established in European practice, they are traditionally subject to strict added-matter analysis. In Mexico, they are accepted with comparatively limited scrutiny, provided they can be plausibly traced to the original disclosure.
A changing patentability landscape and BC&B’s strategic response
The above developments indicate that Mexican pharma–biotech patentability criteria are being reshaped primarily through examination practice, rather than formal legal reform. Inventive step has become an expansive and flexible inquiry, reinforced by heightened evidentiary demands, and by drafting strategies aimed at surviving prosecution instead of by expressing the invention in its most technically coherent form. For general intellectual property practitioners, the challenge is to recognise this convergence and adapt accordingly.
Effective practice before IMPI increasingly requires anticipating not only the legal requirements set out in the statute but also the implicit expectations that now govern how pharmaceutical and biotechnology inventions are assessed in practice.
In this changing context, Becerril, Coca & Becerril (BC&B) has proactively adapted its drafting and prosecution strategies to respond to these heightened requirements without sacrificing claim scope or legal robustness. The firm’s combined experience in chemistry, pharmacy, and biotechnology has enabled it to clearly articulate the inventive step underlying new pharmaceutical formulations, even in scenarios where the innovation may appear incremental or grounded in known principles.
BC&B can point to multiple notable successes in obtaining and defending patents in Mexico, as well as in key foreign areas, including Europe, the US, Canada, and several Latin American countries. In these matters, the firm has consistently succeeded in demonstrating concrete technical advantages – such as improvements in stability, bioavailability, release profiles, or therapeutic compliance – through a carefully calibrated combination of technical argumentation and strategically presented experimental support.
