diff --git a/src/guardrails/checks/text/hallucination_detection.py b/src/guardrails/checks/text/hallucination_detection.py
index e775625..a175076 100644
--- a/src/guardrails/checks/text/hallucination_detection.py
+++ b/src/guardrails/checks/text/hallucination_detection.py
@@ -52,10 +52,7 @@
 from guardrails.spec import GuardrailSpecMetadata
 from guardrails.types import GuardrailLLMContextProto, GuardrailResult
 
-from .llm_base import (
-    LLMConfig,
-    LLMOutput,
-)
+from .llm_base import LLMConfig, LLMOutput, _invoke_openai_callable
 
 logger = logging.getLogger(__name__)
 
@@ -210,9 +207,10 @@ async def hallucination_detection(
         validation_query = f"{VALIDATION_PROMPT}\n\nText to validate:\n{candidate}"
 
         # Use the Responses API with file search and structured output
-        response = await ctx.guardrail_llm.responses.parse(
-            model=config.model,
+        response = await _invoke_openai_callable(
+            ctx.guardrail_llm.responses.parse,
             input=validation_query,
+            model=config.model,
             text_format=HallucinationDetectionOutput,
             tools=[{"type": "file_search", "vector_store_ids": [config.knowledge_source]}],
         )
diff --git a/src/guardrails/checks/text/llm_base.py b/src/guardrails/checks/text/llm_base.py
index c125cea..9ab2077 100644
--- a/src/guardrails/checks/text/llm_base.py
+++ b/src/guardrails/checks/text/llm_base.py
@@ -31,12 +31,16 @@ class MyLLMOutput(LLMOutput):
 
 from __future__ import annotations
 
+import asyncio
+import functools
+import inspect
 import json
 import logging
 import textwrap
-from typing import TYPE_CHECKING, TypeVar
+from collections.abc import Callable
+from typing import TYPE_CHECKING, Any, TypeVar
 
-from openai import AsyncOpenAI
+from openai import AsyncOpenAI, OpenAI
 from pydantic import BaseModel, ConfigDict, Field
 
 from guardrails.registry import default_spec_registry
@@ -45,7 +49,13 @@ class MyLLMOutput(LLMOutput):
 from guardrails.utils.output import OutputSchema
 
 if TYPE_CHECKING:
-    from openai import AsyncOpenAI
+    from openai import AsyncAzureOpenAI, AzureOpenAI  # type: ignore[unused-import]
+else:
+    try:
+        from openai import AsyncAzureOpenAI, AzureOpenAI  # type: ignore
+    except Exception:  # pragma: no cover - optional dependency
+        AsyncAzureOpenAI = object  # type: ignore[assignment]
+        AzureOpenAI = object  # type: ignore[assignment]
 
 logger = logging.getLogger(__name__)
 
@@ -165,10 +175,46 @@ def _strip_json_code_fence(text: str) -> str:
     return candidate
 
 
+async def _invoke_openai_callable(
+    method: Callable[..., Any],
+    /,
+    *args: Any,
+    **kwargs: Any,
+) -> Any:
+    """Invoke OpenAI SDK methods that may be sync or async."""
+    if inspect.iscoroutinefunction(method):
+        return await method(*args, **kwargs)
+
+    loop = asyncio.get_running_loop()
+    result = await loop.run_in_executor(
+        None,
+        functools.partial(method, *args, **kwargs),
+    )
+    if inspect.isawaitable(result):
+        return await result
+    return result
+
+
+async def _request_chat_completion(
+    client: AsyncOpenAI | OpenAI | AsyncAzureOpenAI | AzureOpenAI,
+    *,
+    messages: list[dict[str, str]],
+    model: str,
+    response_format: dict[str, Any],
+) -> Any:
+    """Invoke chat.completions.create on sync or async OpenAI clients."""
+    return await _invoke_openai_callable(
+        client.chat.completions.create,
+        messages=messages,
+        model=model,
+        response_format=response_format,
+    )
+
+
 async def run_llm(
     text: str,
     system_prompt: str,
-    client: AsyncOpenAI,
+    client: AsyncOpenAI | OpenAI | AsyncAzureOpenAI | AzureOpenAI,
     model: str,
     output_model: type[LLMOutput],
 ) -> LLMOutput:
@@ -180,7 +226,7 @@ async def run_llm(
     Args:
         text (str): Text to analyze.
         system_prompt (str): Prompt instructions for the LLM.
-        client (AsyncOpenAI): OpenAI client for LLM inference.
+        client (AsyncOpenAI | OpenAI | AsyncAzureOpenAI | AzureOpenAI): OpenAI client used for guardrails.
         model (str): Identifier for which LLM model to use.
         output_model (type[LLMOutput]): Model for parsing and validating the LLM's response.
 
@@ -190,7 +236,8 @@ async def run_llm(
     full_prompt = _build_full_prompt(system_prompt)
 
     try:
-        response = await client.chat.completions.create(
+        response = await _request_chat_completion(
+            client=client,
             messages=[
                 {"role": "system", "content": full_prompt},
                 {"role": "user", "content": f"# Text\n\n{text}"},
diff --git a/src/guardrails/checks/text/prompt_injection_detection.py b/src/guardrails/checks/text/prompt_injection_detection.py
index fcef929..3e2b905 100644
--- a/src/guardrails/checks/text/prompt_injection_detection.py
+++ b/src/guardrails/checks/text/prompt_injection_detection.py
@@ -36,7 +36,7 @@
 from guardrails.spec import GuardrailSpecMetadata
 from guardrails.types import GuardrailLLMContextProto, GuardrailResult
 
-from .llm_base import LLMConfig, LLMOutput
+from .llm_base import LLMConfig, LLMOutput, _invoke_openai_callable
 
 __all__ = ["prompt_injection_detection", "PromptInjectionDetectionOutput"]
 
@@ -341,9 +341,10 @@ def _create_skip_result(
 
 async def _call_prompt_injection_detection_llm(ctx: GuardrailLLMContextProto, prompt: str, config: LLMConfig) -> PromptInjectionDetectionOutput:
     """Call LLM for prompt injection detection analysis."""
-    parsed_response = await ctx.guardrail_llm.responses.parse(
-        model=config.model,
+    parsed_response = await _invoke_openai_callable(
+        ctx.guardrail_llm.responses.parse,
         input=prompt,
+        model=config.model,
         text_format=PromptInjectionDetectionOutput,
     )
 
diff --git a/tests/unit/checks/test_llm_base.py b/tests/unit/checks/test_llm_base.py
index 907f523..1d77a5f 100644
--- a/tests/unit/checks/test_llm_base.py
+++ b/tests/unit/checks/test_llm_base.py
@@ -34,6 +34,20 @@ def __init__(self, content: str | None) -> None:
         self.chat = SimpleNamespace(completions=_FakeCompletions(content))
 
 
+class _FakeSyncCompletions:
+    def __init__(self, content: str | None) -> None:
+        self._content = content
+
+    def create(self, **kwargs: Any) -> Any:
+        _ = kwargs
+        return SimpleNamespace(choices=[SimpleNamespace(message=SimpleNamespace(content=self._content))])
+
+
+class _FakeSyncClient:
+    def __init__(self, content: str | None) -> None:
+        self.chat = SimpleNamespace(completions=_FakeSyncCompletions(content))
+
+
 def test_strip_json_code_fence_removes_wrapping() -> None:
     """Valid JSON code fences should be removed."""
     fenced = """```json
@@ -64,6 +78,23 @@ async def test_run_llm_returns_valid_output() -> None:
     assert result.flagged is True and result.confidence == 0.9  # noqa: S101
 
 
+@pytest.mark.asyncio
+async def test_run_llm_supports_sync_clients() -> None:
+    """run_llm should invoke synchronous clients without awaiting them."""
+    client = _FakeSyncClient('{"flagged": false, "confidence": 0.25}')
+
+    result = await run_llm(
+        text="General text",
+        system_prompt="Assess text.",
+        client=client,  # type: ignore[arg-type]
+        model="gpt-test",
+        output_model=LLMOutput,
+    )
+
+    assert isinstance(result, LLMOutput)  # noqa: S101
+    assert result.flagged is False and result.confidence == 0.25  # noqa: S101
+
+
 @pytest.mark.asyncio
 async def test_run_llm_handles_content_filter_error(monkeypatch: pytest.MonkeyPatch) -> None:
     """Content filter errors should return LLMErrorOutput with flagged=True."""
diff --git a/tests/unit/checks/test_prompt_injection_detection.py b/tests/unit/checks/test_prompt_injection_detection.py
index 1cda87c..e0d90f5 100644
--- a/tests/unit/checks/test_prompt_injection_detection.py
+++ b/tests/unit/checks/test_prompt_injection_detection.py
@@ -120,3 +120,21 @@ async def failing_llm(*_args: Any, **_kwargs: Any) -> PromptInjectionDetectionOu
 
     assert result.tripwire_triggered is False  # noqa: S101
     assert "Error during prompt injection detection check" in result.info["observation"]  # noqa: S101
+
+
+@pytest.mark.asyncio
+async def test_prompt_injection_detection_llm_supports_sync_responses() -> None:
+    """Underlying responses.parse may be synchronous for some clients."""
+    analysis = PromptInjectionDetectionOutput(flagged=True, confidence=0.4, observation="Action summary")
+
+    class _SyncResponses:
+        def parse(self, **kwargs: Any) -> Any:
+            _ = kwargs
+            return SimpleNamespace(output_parsed=analysis)
+
+    context = SimpleNamespace(guardrail_llm=SimpleNamespace(responses=_SyncResponses()))
+    config = LLMConfig(model="gpt-test", confidence_threshold=0.5)
+
+    parsed = await pid_module._call_prompt_injection_detection_llm(context, "prompt", config)
+
+    assert parsed is analysis  # noqa: S101