Comparative quality assessment of some brands of lisinopril tablets marketed in Lagos, Nigeria

Background: Cardiovascular diseases (CVDs) are number one cause of death across the globe and some classes of drugs are used in its management and treatment. Lisinopril, an angiotensin converting enzyme inhibitor is one of the drugs used to manage the scourge. Quite a large number of Lisinopril brands are spread across Nigeria and there has been reports of loss of efficacy from its use.

Objective: This study was embarked upon to assess the quality of the lisinopril tablets through their physicochemical properties.

Methods: Quality assessment parameters such as hardness, friability, weight uniformity, identification, dissolution profile and assay test were performed on the thirteen different brands of Lisinopril 10 mg tablets. The assay of Active Pharmaceutical Ingredient was done using ultra-violet spectrophotometer and high-performance liquid chromatography. Other tests were conducted based on standard methods of United States Pharmacopeia (USP).

Results: All the brands conformed to USP specifications for weight uniformity and friability. 100 % of the brands passed the hardness test in line with manufacturer's specification. Three out of thirteen brands failed the percentage purity test indicating over 70 % conformity with pharmacopeia purity test. 30.8 % of the brands passed the tablet dissolution profile test.

Conclusion: This study has shown that of all the brands of Lisinopril assessed, only four brands conformed to all the physicochemical tests as specified in the pharmacopoeia monograph hence the need for continuous screening of pharmaceuticals in the open market for quality control assessment and regulatory requirements is imperative.