Health Insights

Medications with the Same Ingredient Do Not Guarantee Equal Efficacy

Pharmacist Kuo, Kuo-Hua (Former Professor, Kaohsiung Medical University)

Pharmaceutical manufacturing is a matter of conscience. The first to know whether a drug works are the patients themselves! Effective medications relieve suffering; ineffective ones not only delay treatment but can even endanger life. Therefore, the primary principle in drug manufacturing should be effective treatment of diseases, with cost considerations coming second.

Pharmacopeias worldwide set minimum quality standards. With technological advancement and modern instrumentation, requirements for drug quality have become increasingly strict. Today, drug efficacy can often be predicted via in vitro instrumental analysis. Thus, advanced countries regularly update their pharmacopeias based on academic research. For example, the United States Pharmacopeia (USP) updates annually, while Taiwan’s Chinese Pharmacopeia updates every five years, with the latest edition released in December 2016 (Edition 8).

Drug manufacturing is not simply “mixing powder with excipients and pressing tablets or filling capsules.” Bioavailability is key to whether a drug can achieve therapeutic effects. Generally, injectable forms are absorbed more effectively than oral forms, but only if the manufacturing process complies with the latest pharmacopeia standards; otherwise, even injectables may carry higher risks.

Oral drugs with the same ingredient and dosage may differ in efficacy when produced by different manufacturers. The difference lies in dissolution and absorption (Dissolution & Bioavailability). Drugs meeting the latest pharmacopeia dissolution standards usually demonstrate reliable therapeutic effects.

However, analyzing drug bioavailability requires animal testing. Conducting this test for every batch is time-consuming, costly, and raises ethical concerns. Therefore, pharmacopeias have established in vitro dissolution tests that simulate in vivo absorption conditions and set minimum acceptable standards. Simply put, the higher a drug’s dissolution rate, the better its therapeutic effect usually is.

Pharmacopeias worldwide continue to update testing standards to ensure that marketed drugs achieve their intended therapeutic effects.

Drug Regulation and International Gaps

In reality, commercial interests or lax regulatory oversight can sometimes overshadow patient health. In Taiwan, drug licenses are valid for five years and must be renewed six months before expiration. Most advanced countries require that renewal applications include evidence that the drug meets the latest pharmacopeia standards from the past five years, ensuring quality compliance.

However, according to Taiwan’s “Guidelines for Drug Registration Review” announced on June 12, 2020, Article 73 allows older drugs to be renewed without meeting the latest pharmacopeia standards. This regulation conflicts with international alignment principles, allowing decades-old drugs, which no longer meet current standards, to remain legally marketed and used clinically.

This has led to situations where drugs with the same ingredient but produced by different manufacturers show significant differences in efficacy. Physicians and patients experience confusion about therapeutic outcomes, which actually stems from disparities in drug quality. Although Taiwanese manufacturers largely comply with PIC/S GMP standards in hardware and software, if drug regulation does not align with international standards, quality inconsistencies persist.

While health insurance systems pursue lower-cost medications, this may come at the expense of patient safety and fair competition between old and new manufacturers. New drug manufacturers must adhere to the latest pharmacopeia standards, while older drugs can be renewed without testing, perpetuating quality gaps.

The government should address this issue by overhauling and eliminating drugs that do not meet the pharmacopeia standards of the past five years to protect public health.

Drug quality is a matter of life. Only by aligning with international standards and adhering to the latest pharmacopeia can we ensure that patients receive safe and effective treatments.