States that enacted reforms to rein in the high cost of drugs dispensed by physicians to injured workers are facing an uphill battle as some doctors are finding ways around the regulations, meaning these costs remain stagnant or are rising in some states, experts say.

“Some of the physician dispensers are trying to dispense in a way that they can maintain the their income (by way of) new strengths of the drugs,” said Dongchun Wang, author of Cambridge, Massachusetts-based Workers Compensation Research Institute’s latest study that highlights newer, more expensive strengths of existing drugs as one of the lead culprits.

“(Pharmaceutical companies) provided a vehicle to dispense those new strengths. …  By doing this, doctors can bypass the new rules,” said Ms. Wang, whose study was released on July 11.

Twenty states have parameters for physician dispensing, with most of the reforms targeting repackaged wholesale pricing of certain drugs and strengths. Eight states do not allow the practice.

Ms. Wang and other researchers analyzed data from 2011 to 2014 for 26 states and found physicians dispensed fewer prescriptions after states enacted reforms that regulated the prices for drugs dispensed by physicians. Yet physician dispensing was still common in post-reform states, with California, Florida, Illinois, Maryland and Pennsylvania still seeing a large portion — 54% to 64% — of pharmaceutical costs coming from doctors who dispense drugs.

Part of the problem is that drug companies have introduced newer versions outside of those addressed in the reforms.

One example cited by experts is that of a popular muscle relaxer that was once only available in 5 milligram and 10 milligram strengths. Now the pill is available at 7.5 milligrams and is one of the drugs that is causing the costs to remain stagnant, according to Ms. Wang.

The WCRI study found that “when dispensing these new drug products, some physician-dispensers were paid much higher prices than they were paid when dispensing existing-strength drug products.

“The results raise questions about the effectiveness and sustainability of the reforms in these states. Almost all of these new drug products were seen among physician-dispensed prescriptions and not among pharmacy-dispensed prescriptions,” the study states.

Critics of physician dispensing say more reform is needed and that the root of the problem is money.

“Pharma is looking to increase their revenue; physicians are looking to increase their revenue,” said Silvia Sacalis, a Tampa-based licensed pharmacist and vice president of clinical services for Healthesystems L.L.C.

“It’s a pure-profit motive,” said Joe Paduda, Skaneateles, New York-based president of CompPharma L.L.C.

Yet in some cases the newer doses can be prescribed as a convenience to a patient who had been cutting pills in half, said Ms. Wang.

Mr. Paduda said the answer is for states to mandate better control of where injured workers can obtain prescriptions.

“The single most powerful thing states can do would be to allow employers to direct injured workers to use contracted pharmacies,” he said.