Background: Good reporting of experimental research is a vital part of research process. Although the reporting guidelines such as Animal research: Reporting in vivo experiments (ARRIVE) require the authors to stick to a standard format, they do not guarantee study reports' validity. For assessing the study reports validity, critical appraisal tools are required.

Objective: The evaluation of the methodological quality of in vivo animal studies of Indian Journal of Pharmacology (IJP) published between 2011 and 2017 through critical appraisal was the primary objective. The secondary objective was to evaluate the adherence of selected studies to the ARRIVE guidelines.

Materials and methods: All in vivo animal studies published as full-text articles in IJP from January 2011 to December 2017 and satisfying the inclusion norms were included. A checklist based on the underlying principles of ARRIVE statement was applied to in vivo animal research (AR) published in IJP. For critical appraisal of reports, risk-of-bias domains were also applied on studies from in vivo AR.

Results: One hundred and sixty-one studies satisfied the inclusion criteria. Seventy-three articles (45.34%, 95% confidence interval [CI]: 0.37-0.53) discussed about randomization procedure. Eighteen articles (11.18%, 95% CI: 0.07-0.16) gave details about blinding when assessing results. None of the studies provided details of sample size calculation. Eight articles (4.97%, 95% CI: 0.02-0.09) commented on the study limitations.

Conclusion: It was found that adherence to only some criteria of ARRIVE guidelines was subpar. There is a need for optimal reporting of random distribution of animals to experimental groups, concealment of allocation, blinded outcome evaluation, computation of sample size, and attrition of animals for improving the validity of AR.